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308-07A-1 308-07A-1Four Wheel Drive (4WD) Systems

DIAGNOSIS AND TESTINGVisual Inspection ChartFour Wheel Drive (4WD) Systems —

Mechanical ElectricalElectronic ShiftRefer to Wiring Diagrams Cell 34 for schematic and • Halfshafts • Junction box (JB) miniconnector information. • Integrated wheel ends fuses:

(IWE) — 11 (10A) (IWESpecial Tool(s) • Shift motor vacuum solenoid)

• Driveshaft and universal — 20 (15A)Worldwide Diagnostic System joints — 29 (15A)(WDS) • Vacuum leaks • Junction box (JB) fuseVehicle Communication Module • Fluid leaks 111 (30A)(VCM) with appropriate • Matching tire sizes • Wiring harnessadapters, or equivalent • Transfer case • Mode select switchdiagnostic tool (MSS)

• Synchronization clutch• Connector(s)• IWE vacuum solenoid73III Automotive Meter• Circuitry 105-R0057 or equivalent

3. If an obvious cause for an observed or reportedconcern is found, correct the cause (if possible)before proceeding to the next step.

4. If the cause is not visually evident, connect the88 Digital Multimeter or diagnostic tool to the data link connector andequivalent select the vehicle to be tested from the105-R0053

diagnostic tool menu. If the diagnostic tool doesnot communicate with the vehicle:

• check that the program card is correctlyinstalled (if using NGS+).

Flex Probe Kit • check the connections to the vehicle.105-R025B • check the ignition switch position.

5. If the diagnostic tool still does not communicatewith the vehicle, refer to the diagnostic tooloperating manual.

6. Carry out the data link diagnostics test. If thediagnostic tool responds with:

Inspection and Verification — Electronic• SCP+, SCP-, UBP or CAN or ISO circuitsShift

fault; all electronic control units no1. Verify the customer concern.response/not equipped, refer to Section

2. Visually inspect for obvious signs of 418-00.mechanical or electrical damage.

• No response/not equipped for powertraincontrol module (PCM). Refer to Section418-00 to diagnose module communicationproblems.

• No response/not equipped for 4x4 module(PCM), GO to Pinpoint Test J.

Copyright 2004, Ford Motor CompanyLast updated: 1/15/2009 2005 F-150, 10/2004


DIAGNOSIS AND TESTING (Continued)

• System passed, retrieve and record the 7. If the DTCs retrieved are related to the concern,continuous diagnostic trouble codes (DTCs), go to the 4x4 Module (PCM) DTC Index toerase the continuous DTCs and carry out the continue diagnostics.self-test diagnostics for the 4x4 module 8. If no DTCs related to the concern are retrieved,(PCM). GO to Symptom Chart.

4x4 Module (PCM) Diagnostic Trouble Code (DTC) Index

DTC Description Source Action

B1317 Battery Voltage High 4x4 Module CHECK the battery and charging system(PCM) for faults. REFER to Section 414-00.

CLEAR the DTC. REPEAT the self-test.

B1318 Battery Voltage Low 4x4 Module CHECK the battery and charging system(PCM) for faults. REFER to Section 414-00.

CLEAR the DTC. REPEAT the self-test.

B1342 ECU is Defective 4x4 Module CLEAR the DTC. REPEAT the self-test.(PCM) If DTC B1342 is retrieved, INSTALL a

4x4 module (integral to PCM). For 4.6Lengine, REFER to Section 303-14.REPEAT the self-test.

C1728 Transfer Case Unable to Transition 4x4 Module GO to Pinpoint Test L.Between 2WD HIGH and 4WD HIGH (PCM)

C1729 Transfer Case Unable to Transition 4x4 Module GO to Pinpoint Test M.Between 4WD HIGH and 4WD LOW (PCM)

C1979 IWE Solenoid Circuit Failure 4x4 Module GO to Pinpoint Test K.(PCM)

C1980 IWE Solenoid Circuit Short to Battery 4x4 Module GO to Pinpoint Test K.(PCM)

P1812 Transmission 4-Wheel Drive Mode Select 4x4 Module GO to Pinpoint Test L.Circuit Failure (PCM)

P1815 Transmission 4-Wheel Drive Mode Select 4x4 Module GO to Pinpoint Test L.Short Circuit to Ground (PCM)

P1820 Transfer Case Clockwise Shift Relay 4x4 Module GO to Pinpoint Test L.Coil Circuit Failure (PCM)

P1822 Transfer Case Clockwise Shift Relay 4x4 Module GO to Pinpoint Test L.Coil Short Circuit To Battery (PCM)

P1824 Transmission 4-Wheel Drive Clutch 4x4 Module GO to Pinpoint Test N.Relay Circuit Failure (PCM)

P1826 Transmission 4-Wheel Drive Low Clutch 4x4 Module GO to Pinpoint Test N.Relay Short Circuit to Battery (PCM)

P1827 Transmission 4-Wheel Drive Low Clutch 4x4 Module GO to Pinpoint Test N.Relay Short Circuit to Ground (PCM)

P1828 Transfer Case Counterclockwise Shift 4x4 Module GO to Pinpoint Test L.Relay Coil Circuit Failure (PCM)

P1830 Transfer Case Counterclockwise Shift 4x4 Module GO to Pinpoint Test L.Relay Coil Short Circuit To Battery (PCM)

P1849 Transmission Transfer Case Contact Plate 4x4 Module GO to Pinpoint Test L.A Short Circuit to Ground (PCM)

P1853 Transmission Transfer Case Contact Plate 4x4 Module GO to Pinpoint Test L.B Short Circuit to Ground (PCM)

2005 F-150, 10/2004



DTC Description Source Action

P1857 Transmission Transfer Case Contact Plate 4x4 Module GO to Pinpoint Test L.C Short Circuit to Ground (PCM)

P1861 Transmission Transfer Case Contact Plate 4x4 Module GO to Pinpoint Test L.D Short Circuit to Ground (PCM)

P1867 Transmission Transfer Case Contact Plate 4x4 Module GO to Pinpoint Test L.General Circuit Failure (PCM)

P1891 Transmission Transfer Case Contact Plate 4x4 Module GO to Pinpoint Test L.Ground Return Open Circuit (PCM)

U1900 CAN Communication BUS Fault — 4x4 Module DIAGNOSE the module communicationReceived Error (PCM) network. REFER to Section 418-00.

U2023 Fault Received From External Node 4x4 Module DIAGNOSE the module communication(PCM) network. REFER to Section 418-00.

U2051 One Or More Calibration Files 4x4 Module Method 3 programming fault. REFER toMissing/Corrupt (PCM) Section 418-00 for 4x4 module (PCM)

programming information.

Symptom Chart

Symptom Chart

Condition Possible Sources Action• No communication with the • Diagnostic tool. • GO to Pinpoint Test J.

4x4 module (PCM) • Data link connector (DLC).• 4x4 module (PCM).• Circuitry.

• The instrument cluster 4L and • Instrument cluster. • GO to Pinpoint Test R.4H indicators do not operate • Circuitry.correctly/do not operate • 4x4 module (PCM).

• The vehicle does not shift • Mode select switch (MSS). • GO to Pinpoint Test L.between 2WD and 4WD • Transfer case.modes correctly • Transfer case clutch.

• Integrated wheel ends (IWEs).• 4x4 module (PCM).• Circuitry.

• The vehicle does not shift • Transfer case. • GO to Pinpoint Test M.between 4H and 4L modes • Mode select switch.correctly • 4x4 module (PCM).

• Transmission drag torque.• 4WD does not engage at • Transfer case clutch coil. • GO to Pinpoint Test N.

speed correctly • 4x4 module (PCM).• Integrated wheel ends (IWEs).

• The front axle does not • Mode select switch. • GO to Pinpoint Test K.engage/disengage • Integrated wheel ends (IWE).correctly/makes noise in 2H • IWE solenoid.under heavy throttle • Vacuum leaks.

• 4x4 module (PCM).• Front halfshaft.

• The 4x4 system jumps out of • Transfer case. • GO to Pinpoint Test O.gear • IWE vent.

• Mode select switch (MSS).• Straightline driveline wind-up • Tire inflation pressure. • GO to Pinpoint Test P.

• Tire and wheel size.• Tire wear.• Axle ratio.

2005 F-150, 10/2004



Symptom Chart (Continued)

Condition Possible Sources Action• Grinding noise during 4WD • Front halfshaft speeds not • GO to Pinpoint Test L.

engagement, especially at turning at the same speed.high speeds • Sychronization clutch.

• Flashing 4x4 high and 4x4 • Loss of CAN communication • CHECK the instrumentlow indicators 3 times every between 4x4 module (PCM) cluster for faults. REFER to2 minutes. and instrument cluster. Section 413-01.

• No communication with the • CHECK 4x4 module (PCM)4x4 module (PCM). communication. GO to

Pinpoint Test J.• The transfer case makes noise • Tire inflation pressure. • MAKE SURE that all tires

• Tire and wheel size. and wheels are the same sizeand that the inflationpressures are correct.

• Tire tread wear. • CHECK tire tread wear to seeif there is more than 0.15 mm(0.06 in) difference in treadwear between front and rear.INTERCHANGE one frontwheel and one rear wheel.ROAD TEST again.

• Internal components. • OPERATE the vehicle in alltransmission gears. If there isnoise in the transmission inNEUTRAL, or in some gearsand not in others, REMOVEand REPAIR thetransmission. REFER toSection 307-01. If there isnoise in all gears,DISASSEMBLE the transfercase. REFER to Section308-07B. CHECK theplanetary gears, the bearings,the upper and lower drivesprockets and drive chain fordamage. INSTALL new partsas necessary.

• Fluid level. • FILL with automatictransmission fluid. REFER toSection 308-07B.

• Unable to duplicate customer • 4x4 system and/or related • CARRY OUT the electronicconcern components. shift on the fly (ESOF)

Functional Test. GO toPinpoint Test Q.

2005 F-150, 10/2004



Connector Circuit Reference

4x4 Module (PCM) C175b (body)

Pin Number(s) Circuit Designation/Description Normal Condition/Measurement

2 CKT 1827 (WH/LG) CAN Bus+ Less than 5 ohms between the DLC and thecommunications circuit. module in concern. Greater than 10,000

ohms between the DLC and ground with allnetwork modules disconnected.

3 CKT 1828 (PK/LG) CAN Bus- Less than 5 ohms between the DLC and thecommunications circuit. module in concern. Greater than 10,000

ohms between the DLC and ground with allnetwork modules disconnected.

12 CKT 1861 (RD) Power circuit to 4x4 module Hot at all times. 9 volts or greater between(PCM) for 4WD functionality. 4x4 module (PCM) and ground. 10,000 ohms

or greater between the 4x4 module (PCM)and ground with the 4x4 module (PCM)disconnected.

13 CKT 1865 (WH/OG) Power circuit to 4x4 Hot at all times. 9 volts or greater betweenmodule (PCM) for 4WD functionality. 4x4 module (PCM) and ground. 10,000 ohms

or greater between the 4x4 module (PCM)and ground with the 4x4 module (PCM)disconnected.

14 CKT 975 (BN/YE) Transfer case shift motor 10,000 ohms or greater between the 4x4clockwise rotation (low to high) relay control module (PCM) and ground with the 4x4

circuit. module (PCM) disconnected. 5 ohms or lessbetween the 4x4 module (PCM) and theclockwise rotation relay. 9 volts or greaterbetween the 4x4 module (PCM) and groundwith the clockwise relay connected.

15 CKT 976 (OG) Transfer case shift motor 10,000 ohms or greater between the 4x4counterclockwise rotation (high to low) relay module (PCM) and ground with the 4x4

control circuit. module (PCM) disconnected. 5 ohms or lessbetween the 4x4 module (PCM) and thecounterclockwise rotation relay. 9 volts orgreater between the 4x4 module (PCM) andground with the clockwise relay connected.

16 CKT 605 (RD) Integrated wheel end (IWE) 10,000 ohms or greater between the 4x4solenoid control circuit. module (PCM) and ground with the 4x4

module (PCM) and the IWE solenoiddisconnected. 5 ohms or less between the4x4 module (PCM) and IWE solenoid.

2005 F-150, 10/2004




31 CKT 682 (DB) 4WD Mode select switch 10,000 ohms or greater between the 4x4(MSS) signal return circuit. module (PCM) and ground with the 4x4

module (PCM) and MSS disconnected. 5ohms or less between the 4x4 module (PCM)and MSS.

32 CKT 780 (DB) 4WD Mode select switch 10,000 ohms or greater between the 4x4(MSS) signal circuit. module (PCM) and ground with the 4x4


51 CKT 361 (RD) VPWR circuit. Hot in RUN/START. 9 volts or greaterbetween 4x4 module (PCM) and ground.10,000 ohms or greater between the 4x4module (PCM) and ground with the 4x4module (PCM) disconnected.



67 CKT 570a (BK/WH) 4x4 module (PCM) 5 ohms or less between the 4x4 moduleground circuit. (PCM) and ground.

68 CKT 570b (BK/WH) 4x4 module (PCM) 5 ohms or less between the 4x4 moduleground circuit. (PCM) and ground.

69 CKT 570c (BK/WH) 4x4 module (PCM) 5 ohms or less between the 4x4 moduleground circuit. (PCM) and ground.

70 CKT 570d (BK/WH) 4x4 module (PCM) 5 ohms or less between the 4x4 moduleground circuit. (PCM) and ground.

2005 F-150, 10/2004



4x4 Module (PCM) C175t (transmission)


6 CKT 770 (WH) Transfer case shift motor 10,000 ohms or greater between the 4x4position contact plate encoder signal position module (PCM) and ground with the 4x4

1. module (PCM) and the transfer casedisconnected. 5 ohms or less between the4x4 module (PCM) and the transfer case.

7 CKT 771 (VT/YE) Transfer case shift motor 10,000 ohms or greater between the 4x4position contact plate encoder signal position module (PCM) and ground with the 4x4


8 CKT 772 (LB) Transfer case shift motor 10,000 ohms or greater between the 4x4position contact plate encoder signal position module (PCM) and ground with the 4x4


9 CKT 778 (OG) Transfer case shift motor 10,000 ohms or greater between the 4x4position contact plate encoder signal position module (PCM) and ground with the 4x4


46 CKT 782 (BN/WH) Transfer case shift motor 10,000 ohms or greater between the 4x4position contact plate encoder signal return. module (PCM) and ground with the 4x4

module (PCM) and the transfer casedisconnected. 5 ohms or less between the4x4 module (PCM) and the transfer case.

48 CKT 92 (LB/YE) Transfer case 10,000 ohms or greater between the 4x4synchronization clutch signal return circuit. module (PCM) and ground with the 4x4


49 CKT 779 (BN) Transfer case synchronization 10,000 ohms or greater between the 4x4clutch power supply circuit. module (PCM) and ground with the 4x4


2005 F-150, 10/2004



Mode Select Switch (MSS) C284


2 CKT 682 (DB) 4WD Mode select switch 10,000 ohms or greater between the 4x4(MSS) signal return circuit. module (PCM) and ground with the 4x4


3 CKT 780 (DB) 4WD Mode select switch 10,000 ohms or greater between the 4x4(MSS) signal circuit. module (PCM) and ground with the 4x4


Transfer Case C350


1 CKT 771 (VT/YE) Transfer case shift motor 10,000 ohms or greater between the 4x4position contact plate encoder signal position module (PCM) and ground with the 4x4


5 CKT 770 (WH) Transfer case shift motor 10,000 ohms or greater between the 4x4position contact plate encoder signal position module (PCM) and ground with the 4x4


9 CKT 772 (LB) Transfer case shift motor 10,000 ohms or greater between the 4x4position contact plate encoder signal position module (PCM) and ground with the 4x4


2005 F-150, 10/2004




10 CKT 782 (BN/WH) Transfer case shift motor 10,000 ohms or greater between the 4x4position contact plate encoder signal return. module (PCM) and ground with the 4x4


12 CKT 92 (LB/YE) Transfer case 10,000 ohms or greater between the 4x4synchronization clutch signal return circuit. module (PCM) and ground with the 4x4


13 CKT 778 (OG) Transfer case shift motor 10,000 ohms or greater between the 4x4position contact plate encoder signal position module (PCM) and ground with the 4x4


14 CKT 785 (BK/LG) Transfer case shift motor 10,000 ohms or greater between thecounterclockwise rotation power supply counterclockwise rotation relay and ground

circuit. with the counterclockwise relay and transfercase disconnected. 5 ohms or less betweenthe counterclockwise relay and the transfercase.

15 CKT 786 (RD) Transfer case shift motor 10,000 ohms or greater between theclockwise rotation power supply circuit. clockwise rotation relay and ground with the

clockwise relay and transfer casedisconnected. 5 ohms or less between theclockwise relay and the transfer case.

16 CKT 779 (BN) Transfer case synchronization 10,000 ohms or greater between the 4x4clutch power supply circuit. module (PCM) and ground with the 4x4


Integrated Wheel End (IWE) Solenoid C1290


1 CKT 605 (RD) IWE solenoid control circuit. 10,000 ohms or greater between the IWEsolenoid and ground with the IWE solenoidand the 4x4 module (PCM) disconnected. 5ohms or less between the IWE solenoid andthe 4x4 module (PCM).

2 CKT 883 (PK/LB) IWE solenoid power Hot at all times. 9 volts or greater betweensupply circuit. the IWE solenoid and ground. 10,000 ohms

or greater between the IWE solenoid andground with the IWE solenoid disconnected.

2005 F-150, 10/2004



Shift Motor Clockwise Rotation Relay/Shift Motor Counterclockwise Rotation Relay


1 (CW) CKT 975 (BN/YE) Transfer case shift motor 10,000 ohms or greater between theclockwise rotation relay control circuit. clockwise relay and ground with the

clockwise relay and the 4x4 module (PCM)disconnected. 5 ohms or less between theclockwise relay and the 4x4 module (PCM).

1 (CCW) CKT 976 (OG) Transfer case shift motor 10,000 ohms or greater between thecounterclockwise rotation relay control clockwise relay and ground with the

circuit. clockwise relay and the 4x4 module (PCM)disconnected. 5 ohms or less between theclockwise relay and the 4x4 module (PCM).

2 (CW) CKT 704d (DG/LG) Transfer case shift Hot at all times. 9 volts or greater betweenmotor clockwise rotation relay power supply the clockwise relay and ground.

circuit.

2 (CCW) CKT 704b (DG/LG) Transfer case shift Hot at all times. 9 volts or greater betweenmotor counterclockwise rotation relay power the clockwise relay and ground.

supply circuit.

3 (CW) CKT 786 (RD) Transfer case shift motor 10,000 ohms or greater between theclockwise rotation power supply circuit. clockwise rotation relay and ground with the

clockwise relay and transfer casedisconnected. 5 ohms or less between theclockwise relay and the transfer case.

3 (CCW) CKT 785 (BK/LG) Transfer case shift motor 10,000 ohms or greater between thecounterclockwise rotation power supply clockwise rotation relay and ground with the

circuit. clockwise relay and transfer casedisconnected. 5 ohms or less between theclockwise relay and the transfer case.

4 CKT 57a/b (BK) Relay ground circuit. 5 ohms or less between connector pin andground.

Possible CausesPinpoint Tests

• Power supply:Pinpoint Test J: No Communication With the4x4 Module (PCM) — circuit 1861 (RD)

Refer to Wiring Diagrams Cell 34 for schematic and — circuit 1865 (WH/OG)connector information. • Power distribution junction box (PDJB)

mini-fuses:Normal OperationIn order for the 4x4 module (PCM) to communicate — 20 (15A)with the scan tool, the operating voltage required to — 29 (15A)supply the 4x4 module (PCM) is in a range between

• Charging system.9 and 16 volts. Voltage is supplied by circuit 1861(RD) and circuit 1865 (WH/OG). • Battery.

2005 F-150, 10/2004


DIAGNOSIS AND TESTING (Continued)PINPOINT TEST J: NO COMMUNICATION WITH THE 4x4 MODULE (PCM)

NOTICE: Use the Flex Probe Kit for all test connections to prevent damage to the wiringterminals. Do not use standard multimeter probes.

Test Step Result / Action to TakeJ1 CHECK FOR DIAGNOSTIC TOOL COMMUNICATION WITH THE

VEHICLE• Verify diagnostic tool communication with the vehicle.

— If using the using WDS, follow the directions and carry outYesthe network test.GO to J2.— If using NGS, verify that the correct cable is used and the

vehicle and engine selection information is correct. No• WDS: Does the network test pass for the PCM? REFER to the appropriate diagnostic tool

NGS: Does the diagnostic tool communicate with the PCM? manual for further diagnosis.J2 CHECK FOR VOLTAGE INPUT TO THE 4x4 MODULE (PCM)

• Disconnect: 4x4 Module (PCM) C175b. Yes• Measure the voltage between C175b-12, circuit 1861 (RD), GO to J6.harness side and ground; and between C175b-13, circuit 1865(WH/OG) and ground. No

• Are the voltages greater than 9 volts? GO to J3.J3 CHECK THE POWER DISTRIBUTION JUNCTION BOX (PDJB)

MINI-FUSES• Check PDJB mini-fuses 20 (15A) and 29 (15A). Yes• Are the fuses okay? GO to J4.

NoCHECK circuit 1861 (RD) and circuit 1865(WH/OG). REPAIR as necessary.REPEAT the self-test.

J4 CHECK FOR BATTERY VOLTAGE FROM THE JUNCTION BOX(JB)• Ignition ON. Yes• Measure the voltage between JB input side fuse cavity 20 and REPAIR or INSTALL new components as

ground; and between JB input side fuse cavity 29 and ground. necessary. REPEAT the self-test.• Are the voltages greater than 9 volts? No

GO to J5.J5 CHECK THE BATTERY VOLTAGE WITH THE ENGINE RUNNING

• Start the engine. Measure the battery voltage at the positive Yesbattery terminal. REPAIR circuit 1861 (RD) or 1865

• Is the voltage greater than 9 volts? (WH/OG). REPEAT the self-test.NoCHECK the charging system. REFER toSection 414-00.

J6 CHECK THE GROUND CIRCUITS FOR AN OPEN• Disconnect the battery ground cable. Refer to Section 414-01.• Disconnect: 4x4 Module (PCM) C175b. Yes• Measure the resistance between C175b-66, circuit 567 (LB/YE) GO to J7.and ground; and between C175b-67, circuits 570a C175b-68,

circuit 570b C175b-69, circuits 570c C175b-70 circuit 570d, No(BK/WH) and ground. REPAIR the affected circuit(s). REPEAT

• Are the resistances less than 5 ohms? the self-test.J7 CHECK THE VOLTAGE ON GROUND CIRCUITS

• Measure the voltage between C175b-66, circuit 567 (LB/YE) and Yesground; and between C175b-67, circuit 570a, C175b-68, circuit REPAIR the affected circuit(s). REPEAT570b, C175b-69, circuit 570c, C175b-70, circuit 570d and the self-test.ground. No• Is voltage present? Disconnect all 4x4 module (PCM)

connectors. CHECK for corrosion, and/orpushed-out pins. The condition may havebeen caused by a loose or corrodedconnector. REPAIR or CLEAN asnecessary.If not, INSTALL a new 4x4 module(integral to the PCM). REFER to Section303-14. TEST the system for normaloperation.

2005 F-150, 10/2004



Possible CausesPinpoint Test K: The Front Axle Does NotEngage/Disengage Correctly/Makes Noise In • Mode select switch2H Under Heavy Throttle

• Integrated wheel end (IWE)Normal Operation

• IWE solenoidIn 2WD, the 4x4 module (PCM) supplies a ground• Transfer casepath to the IWE solenoid to apply vacuum to the

integrated wheel ends (disengaging the front hubs • Vacuum leaksfrom the front axle). In 4WD, the 4x4 module

• Front axle assembly(PCM) does not supply the ground path to the IWE

• 4x4 module (PCM)solenoid, vacuum is not applied to the integratedwheel ends and an internal spring keeps the hubs • Circuit 605 (RD)engaged. Systematically check the necessary inputs • Circuit 883 (BK/LB)and outputs at the 4x4 module (PCM), internal

• CJB fuse 11 (10A)components of the transfer case, mode select switch,IWE components and drive axles.

PINPOINT TEST K: THE FRONT AXLE DOES NOT ENGAGE/DISENGAGE CORRECTLY/MAKES NOISE IN2H UNDER HEAVY THROTTLE

Test Step Result / Action to TakeK1 CHECK FOR DTCs

• Ignition OFF. Yes• Connect the scan tool. If DTC C1979 is retrieved, GO to K13.• Ignition ON. If DTC C1980 is retrieved, GO to K15.• Carry out the on-demand self test.

No• Are DTCs C1979 or C1980 present?GO to K2.

K2 CHECK FOR GRINDING NOISES AT HIGH SPEEDS• Turn the MSS from 2WD to 4WD at rest. Drive the vehicle.• Turn the MSS from 2WD to 4WD while driving the vehicle at low Yesspeed. REFER to Section 205-00 to diagnose• Turn the MSS case from 2WD to 4WD while driving the vehicle excessive front axle noise/chatter/grindingat high speed. during 4X4 engagement.• Is the axle system fully functional at rest, but there is a

grinding noise during engagement, especially at high Nospeed? GO to K3.

K3 CHECK THE TRANSFER CASE SHIFT TO 2H• Ignition OFF.• Connect the scan tool.• Ignition ON.• NOTE: If it is difficult to read the motor position, use the active

command to energize the transfer case motor contact plateposition return circuit.Monitor the 4x4 module (PCM) PID for the contact plate positionwhile switching the MSS to 2H.

Contact Plate PositionMode Select1 (A) 2 (B) 3 (C) 4 (D)Switch Position

2H CLOSED OPEN CLOSED CLOSED

4H OPEN CLOSED CLOSED OPEN

Yes4L OPEN CLOSED OPEN CLOSEDGO to K4.

• Does the 4x4 module (PCM) PID and instrument cluster Noindicator lamp indicate that vehicle shifted into 2H? GO to Pinpoint Test L.

K4 CHECK THE IWE DISENGAGEMENT• Raise and support the vehicle off the ground until the front

wheels can be spun freely. Refer to Section 100-02.

(Continued)

2005 F-150, 10/2004


DIAGNOSIS AND TESTING (Continued)PINPOINT TEST K: THE FRONT AXLE DOES NOT ENGAGE/DISENGAGE CORRECTLY/MAKES NOISE IN

2H UNDER HEAVY THROTTLE (Continued)

Test Step Result / Action to TakeK4 CHECK THE IWE DISENGAGEMENT (Continued)

• NOTE: The engine must be idling during the following steps tosupply vacuum to the IWE solenoid.Start the engine and allow to idle.

• Switch the MSS to 2H.• Rotate the left front tire one revolution forward and one Yesrevolution backward while observing the left front halfshaft. GO to K10.• Rotate the right front tire one revolution forward and one

revolution backward while observing the right front halfshaft. No• Did either front halfshaft rotate? GO to K5.

K5 CHECK THE TRANSFER CASE SHIFT INTO 4H• NOTE: If it is difficult to read the motor position, use the active

command to energize the transfer case motor contact plateposition return circuit.Monitor the 4x4 module (PCM) PID for the contact plate positionwhile switching the MSS to 4H.



4H OPEN CLOSED CLOSED OPEN

Yes4L OPEN CLOSED OPEN CLOSEDGO to K6.

• Does the 4x4 module (PCM) PID and instrument cluster Noindicator lamp indicate that the MSS in 4H? GO to Pinpoint Test L.

K6 CHECK THE IWE ENGAGEMENT• Raise and support the vehicle off the ground until the front

wheels can be spun freely. Refer to Section 100-02.• NOTE: The engine must be idling during the following steps to

supply vacuum to the IWE solenoid.YesStart the engine and allow to idle. CHECK that all driveline fasteners are• Switch the MSS to 4H. present and tightened to specification.• Rotate the left front tire one revolution forward and one REFER to Section 205-00 for furtherrevolution backward while observing the left front halfshaft. diagnosis of the front axle.• Rotate the right front tire one revolution forward and one

revolution backward while observing the right front halfshaft. No• Did both front halfshafts rotate? GO to K7.

K7 CHECK THE IWE SOLENOID OUTPUT IN 4H• NOTE: The engine must be idling during the following steps to

supply vacuum to the IWE solenoid.Start the engine. Yes• Disconnect the output vacuum line at the IWE solenoid. Key in OFF position. GO to K25.• Switch the MSS to 4H.

• Measure the vacuum at the output port of the IWE solenoid. No• Is the vacuum less than 25 mm (1 in) Hg? GO to K8.

K8 CHECK THE IWE SOLENOID OUTPUT IN 4H WITH THEDIAGNOSTIC TOOL• Ignition OFF.• Connect the scan tool.• NOTE: The engine must be idling during the following steps to

supply vacuum to the IWE solenoid.Start the engine.

• Enter the following diagnostic mode on the diagnostic tool:Active Command. Yes• Using the diagnostic tool, command the IWE solenoid to engage End active command. GO to K19.the IWEs (solenoid OFF).

• Measure the vacuum at the output port of the IWE solenoid. No• Is the vacuum less than 25 mm (1 in) Hg? GO to K9.

(Continued)

2005 F-150, 10/2004




Test Step Result / Action to TakeK9 CHECK THE IWE SOLENOID

• Disconnect: IWE Solenoid C1290. Yes• Measure the vacuum at the output port of the IWE solenoid. End active command. GO to K17.• Is the vacuum less than 25 mm (1 in) Hg? No

End active command. INSTALL a newIWE solenoid. REPEAT the self-test.

K10 CHECK THE IWE SOLENOID OUTPUT VACUUM IN 2WD• NOTE: The engine must be idling during the following steps to

supply vacuum to the IWE solenoid.Start the engine. Yes• Disconnect the output vacuum line at the IWE solenoid. GO to K20.• Switch the MSS to 2H.

• Measure the vacuum at the output port of the IWE solenoid. No• Is the vacuum greater than 254 mm (10 in) Hg? GO to K11.

K11 CHECK THE IWE SOLENOID INPUT VACUUM• Measure the vacuum at the input port of the IWE solenoid. Yes• Is the vacuum greater than 254 mm (10 in) Hg? GO to K12.

NoREPAIR the vacuum leak. CLEAR theDTCs. REPEAT the self-test.

K12 CHECK THE IWE SOLENOID OUTPUT IN 2WD WITH THEDIAGNOSTIC TOOL• Ignition OFF.• Connect the scan tool.• NOTE: The engine must be idling during the following steps to

supply vacuum to the IWE solenoid.Start the engine.

• Enter the following diagnostic mode on the diagnostic tool:Active Command. Yes• Using the diagnostic tool, command the IWE solenoid to End active command. GO to K19.disengage the IWEs (IWE solenoid ON).

• Measure the vacuum at the output port of the IWE solenoid. No• Is the vacuum greater than 254 mm (10 in) Hg? End active command. GO to K13.

K13 CHECK CIRCUIT 883 (BK/LB) FOR VOLTAGE• Ignition OFF.• Disconnect: IWE Solenoid C1290.• Measure the voltage between IWE solenoid C1290-2, circuit 883

(BK/LB) and ground.

YesGO to K14.NoCHECK CJB fuse 11 (10A). VERIFY thatthe fuse blows when the air conditioning(A/C) system compressor cycles. If thisoccurs, REFER to Section 412-00.REPAIR the circuit as necessary. CLEAR

• Is the voltage greater than 9 volts? the DTCs. REPEAT the self-test.K14 CHECK THE IWE SOLENOID OPERATION

• Connect: IWE Solenoid C1290.

(Continued)

2005 F-150, 10/2004




Test Step Result / Action to TakeK14 CHECK THE IWE SOLENOID OPERATION (Continued)

• NOTE: The engine must be idling during the following steps tosupply the vacuum required for the IWEs to engage anddisengage.

YesStart the engine. DISCONNECT the fused jumper. GO to• Connect a 10 amp fused jumper wire between the IWE solenoid K15.C1290-1, circuit 605 (RD), component side and ground.• Measure the vacuum at the IWE solenoid output vacuum port. No• Is the IWE solenoid output port vacuum greater than 254 INSTALL a new IWE solenoid. CLEAR the

mm (10 in) Hg? DTCs. REPEAT the self-test.K15 CHECK CIRCUIT 605 (RD) FOR A SHORT TO VOLTAGE

• Ignition OFF.• Disconnect: IWE Solenoid C1290.• Disconnect: 4x4 Module (PCM) C175b.• Ignition ON.• Measure the voltage between IWE solenoid C1290-1, circuit 605

(RD), harness side and ground.

YesREPAIR the circuit. CLEAR the DTCs.REPEAT the self-test.No

• Is voltage present? GO to K16.K16 CHECK CIRCUIT 605 (RD) FOR AN OPEN

• Ignition OFF.• Measure the resistance between IWE solenoid C1290-1, circuit

605 (RD), harness side and 4x4 module (PCM) C175b-16, circuit605 (RD), harness side.

YesGO to K17.NoREPAIR the circuit. CLEAR the DTCs.

• Is the resistance less than 5 ohms? REPEAT the self-test.K17 CHECK CIRCUIT 605 (RD) FOR A SHORT TO GROUND

• Ignition OFF.• Disconnect: 4x4 Module (PCM) C175b.

(Continued)

2005 F-150, 10/2004




Test Step Result / Action to TakeK17 CHECK CIRCUIT 605 (RD) FOR A SHORT TO GROUND

(Continued)

• Measure the resistance between IWE solenoid C1290-1, circuit605 (RD), harness side and ground.

YesGO to K18.NoREPAIR the circuit. CLEAR the DTCs.

• Is the resistance greater than 10,000 ohms? REPEAT the self-test.K18 CHECK THE IWE SOLENOID RESISTANCE

• Measure the resistance between IWE solenoid C1290-1 andC1290-2, component side.

YesGO to K19.NoINSTALL a new IWE solenoid. CLEAR the

• Is the resistance between 68 and 78 ohms? DTC(s). REPEAT the self-test.K19 CHECK THE 4x4 MODULE

• Disconnect all 4x4 module (PCM) connectors. Yes• Check for: INSTALL a new 4x4 module (integral to

PCM). For 4.6L engine, REFER to Section— corrosion 303-04A. For 5.4L engine, REFER to— pushed-out pins Section 303-04B. CLEAR the DTCs.• Connect all 4x4 module (PCM) connectors and make sure they REPEAT the self-test.are seated correctly.• Operate the system and verify the concern is still present. No• Is the concern still present? The system is operating correctly at this

time. Concern may have been caused bya loose or corroded connector. CLEAR theDTCs. REPEAT the self-test.

K20 CHECK THE IWE VACUUM SYSTEM• Ignition OFF.• Disconnect both vacuum lines from the IWE solenoid. Yes• Using a vacuum pump, apply 508 mm (20 in) Hg of vacuum to GO to K21.the IWE system through the apply vacuum circuit.• Observe the vacuum reading. No• Did the vacuum drop more than 25 mm (1 in) Hg per CONNECT the vacuum lines to the IWE

minute? solenoid. GO to K24.

(Continued)

2005 F-150, 10/2004




Test Step Result / Action to TakeK21 CHECK THE RH IWE LEAK RATE

• Raise and support the vehicle on a hoist. Refer to Section100-02. Yes• Disconnect the vacuum line from the larger port on the RH IWE. INSTALL a new IWE. REFER to Section• Apply 508 mm (20 in) Hg of vacuum to the RH IWE port and 205-04. GO to K19.observe vacuum reading.

• Did the vacuum drop more than 25 mm (1 in) Hg per Nominute? GO to K22.

K22 CHECK THE LH IWE LEAK RATE• Disconnect the vacuum line from the larger port at the LH IWE. Yes• Apply 508 mm (20 in) Hg of vacuum to the LH IWE port and INSTALL a new IWE. REFER to Section

observe vacuum reading. 205-04. GO to K20.• Did the vacuum drop more than 25 mm (1 in) Hg per Nominute? GO to K23.

K23 CHECK THE IWE VACUUM SUPPLY TUBE• Disconnect both vacuum lines from the IWE solenoid. Yes• Plug both LH and RH IWE vacuum lines. Apply 508 mm (20 in) INSTALL new vacuum lines as necessary.Hg of vacuum to the IWE apply vacuum circuit and observe the GO to K19.vacuum reading.• Did the vacuum drop more than 25 mm (1 in) Hg per No

minute? GO to K24.K24 CHECK THE IWE VACUUM SUPPLY AT EACH IWE IN 2H

• Connect a hand-held vacuum gauge to the LH IWE vacuumsupply tube.

• NOTE: The engine must be idling during the following steps tosupply the vacuum required for the IWEs to engage and

Yesdisengage.GO to K27.Start the engine.

• Switch the MSS to 2H while observing the vacuum gauge. No• Repeat these steps for the RH IWE. INSTALL new vacuum lines as necessary.• Are the vacuum readings greater than 254 mm (10 in) Hg? GO to K20.

K25 CHECK THE LH IWE VACUUM LINE FOR AN OBSTRUCTION• Disconnect both vacuum lines from the IWE solenoid.• Raise and support the vehicle on a hoist. Refer to Section Yes100-02. INSTALL a new vacuum line. CLEAR the• Disconnect the vacuum line at the LH IWE. DTCs. REPEAT the self-test.• Connect a hand vacuum pump to the LH IWE vacuum line and

attempt to draw a vacuum on the line. No• Did the vacuum pump draw a vacuum on the LH IWE CONNECT the vacuum line to the LH

vacuum line? IWE. GO to K26.K26 CHECK THE RH IWE VACUUM LINE FOR AN OBSTRUCTION

• Disconnect the larger vacuum line at the RH IWE. Yes• Connect a vacuum pump to the RH IWE vacuum line and INSTALL a new vacuum line. CLEAR the

attempt to draw a vacuum on the line. DTCs. REPEAT the self-test.• Did the vacuum pump draw a vacuum on the RH IWE Novacuum line? CONNECT the vacuum line to the RH

IWE. GO to K27.K27 CHECK THE LH IWE OPERATION

• Raise and support the vehicle on a hoist. Refer to sectionSection 100-02. Yes• Connect a vacuum pump to the larger IWE vacuum port. GO to K28.• Observe the LH halfshaft while rotating the LH front tire. Applyand release vacuum to manually engage and disengage the LH NoIWE. INSTALL a new LH IWE. REFER to

• Did the LH IWE disengage between 152 and 203 mm (6 to 8 Section 205-04. CLEAR the DTCs.in) Hg? REPEAT the self-test.

(Continued)

2005 F-150, 10/2004




Test Step Result / Action to TakeK28 CHECK THE RH IWE OPERATION

• Connect a vacuum pump to the larger RH IWE vacuum port. Yes• Observe the RH halfshaft while rotating the RH front tire. Apply CLEAR the DTC(s). REPEAT the self-test.

and release vacuum to manually engage and disengage the LH GO to Pinpoint Test Q.IWE. No• Did the RH IWE disengage between 152 and 203 mm (6 to 8 INSTALL a new RH IWE. REFER toin) Hg? Section 205-04. CLEAR the DTCs.

REPEAT the self-test.

Possible CausesPinpoint Test L: The Vehicle Does Not ShiftBetween 2WD And 4WD Modes Correctly • Transfer caseNormal Operation • Integrated wheel ends (IWE)The mode select switch communicates the operator’s

• IWE solenoidchoice to the 4x4 module (PCM). The 4x4 module

• 4x4 module (PCM)(PCM) then controls the transfer case clutch,transfer case motor and integrated wheel ends • Front axle assembly(IWEs) as necessary. If the vehicle is not • Circuit 605 (RD)responding to the operator’s intentions,

• Circuit 883 (BK/LB)systematically check the necessary inputs andoutputs of the 4x4 module (PCM), components of • Mode select switch (MSS)the transfer case, IWE components and halfshafts.Check all circuits for opens and shorts to power orground.

PINPOINT TEST L: THE VEHICLE DOES NOT SHIFT BETWEEN 2WD AND 4WD MODES CORRECTLY

Test Step Result / Action to TakeL1 CHECK FOR DTCs

• Connect the scan tool. Yes• Carry out the 4x4 module (PCM) on-demand self test. If DTC P1812, GO to L5. If DTC P1815,• Are DTCs retrieved? GO to L7. DTC P1867 or P1891, GO to

L15. If DTC P1849, P1853, P1857, orP1861, GO to L17. If DTC P1820 orP1828, GO to L21. If DTC P1822 orP1830, GO to L28.NoGO to L2.

L2 CHECK THE IGNITION SWITCH STATUS PID• Ignition ON. Yes• Monitor the ignition switch status PID. GO to L3.• Do the ignition switch PIDs match the ignition switch Nopositions? CHECK the ignition switch. REFER to

Section 413-00. After the fault is repaired,CLEAR the DTC. REPEAT the self-test.

L3 CHECK THE MODE SELECT SWITCH (MSS) POSITION PIDS• Ignition OFF. Yes• Connect the scan tool. GO to L8.• Ignition ON.• Monitor each MSS PID while cycling through each MSS position. No• Does each MSS PID agree with each switch position? GO to L4.

L4 CHECK THE MSS• Ignition OFF.• Disconnect: MSS C284.• Measure the resistance between MSS C284, terminals 2 and 3,

while rotating the switch through all positions. Refer to thefollowing chart.

(Continued)

2005 F-150, 10/2004


DIAGNOSIS AND TESTING (Continued)PINPOINT TEST L: THE VEHICLE DOES NOT SHIFT BETWEEN 2WD AND 4WD MODES CORRECTLY

(Continued)

Test Step Result / Action to TakeL4 CHECK THE MSS (Continued)

Mode Select Switch (MSS)Position Resistance

4L 130 ohms

4H 270 ohms

2H 620 ohms

YesGO to L5.NoINSTALL a new MSS. REFER to ModeSelect Switch (MSS). CLEAR the DTC(s).

• Are the resistance values within specification? REPEAT the self-test.L5 CHECK CIRCUITS 682 (DB) AND 780 (DB) FOR AN OPEN

• Measure the resistance between MSS C284-2, harness side and4x4 module (PCM) C175b-31, harness side, circuit 682 (DB).

YesGO to L6.

• Measure the resistance between MSS C284-3, harness side and No4x4 module (PCM) C175b-32, harness side, circuit 780 (DB). REPAIR the affected circuit(s). CLEAR the

• Is the resistance less than 5 ohms? DTC(s). REPEAT the self-test.

(Continued)

2005 F-150, 10/2004



(Continued)

Test Step Result / Action to TakeL6 CHECK CIRCUITS 682 (DB) AND 780 (DB) FOR SHORT TO

VOLTAGE• Measure the voltage between MSS C284-2, harness side and

ground.

YesREPAIR the affected circuit(s). CLEAR theDTC(s). REPEAT the self-test.• Measure the voltage between MSS C284-3, harness side and

ground. No• Is voltage present? GO to L7.

L7 CHECK CIRCUITS 682 (DB) AND 780 (DB) FOR SHORT TOGROUND• Measure the resistance between MSS C284-2, harness side and

ground.

YesGO to L29.

• Measure the resistance between MSS C284-3, harness side and Noground. REPAIR the affected circuit(s). CLEAR the

• Is the resistance greater than 10,000 ohms? DTC(s). REPEAT the self-test.L8 CHECK FOR 4H WIND-UP

• Switch the MSS to 4H. Yes• Drive the vehicle on a dry, hard surface in turns. GO to L11.• Is wind-up present in turns? No

GO to L9.L9 CHECK FOR TRANSFER CASE ENGAGEMENT

• Raise and support the vehicle. Refer to Section 100-02. Yes• Rotate the rear driveshaft. GO to L10.• Observe the front driveshaft. No• Did the front driveshaft rotate? GO to L13.

(Continued)

2005 F-150, 10/2004



(Continued)

Test Step Result / Action to TakeL10 CHECK FOR IWE ENGAGEMENT

• NOTE: The engine must be at idle during the following steps tosupply vacuum for IWE engagement/disengagement.Start the engine and allow to idle. Yes• Rotate the left front tire one revolution forward and one CHECK that all driveline fasteners arerevolution backward while observing the left front halfshaft and present and tightened to specification.universal joint. REFER to Section 205-00 for further• Rotate the right front tire one revolution forward and one diagnosis of the front axle.revolution backward while observing the right front halfshaft anduniversal joint. No

• Did the front halfshafts rotate? GO to Pinpoint Test K.L11 CHECK FOR IWE DISENGAGEMENT

• Switch the MSS to 2H.• Rotate the left front tire one revolution forward and one

revolution backward while observing the left front halfshaft anduniversal joint. Yes• Rotate the right front tire one revolution forward and one GO to Pinpoint Test K.revolution backward while observing the right front halfshaft anduniversal joint. No

• Did either front axle shaft and universal joint rotate? GO to L12.L12 CHECK FOR TRANSFER CASE DISENGAGEMENT

• Raise the vehicle on hoist. Refer to Section 100-02. Yes• Rotate the rear driveshaft while observing the front driveshaft. The system is functioning correctly.• Does the front driveshaft rotate? No

GO to L13.L13 CHECK THE TRANSFER CASE CONTACT PLATE POSITION

PIDS• Connect the scan tool.• Monitor the transfer case contact plate position PID.• NOTE: If it is difficult to read the motor position, use the active

command to energize the transfer case motor contact plateposition return circuit.Switch the MSS from 2H to 4H.



4H OPEN CLOSED CLOSED OPEN YesGO to L30.4L OPEN CLOSED OPEN CLOSEDNo

• Does the transfer case contact plate PID indicate 4H? GO to L14.L14 CHECK THE TRANSFER CASE SHIFT MOTOR OPERATION

• Remove the transfer case shift motor from the transfer case,leaving the wiring connector connected. Yes• Observe the transfer case shift motor while switching the MSS GO to L30.from 2H to 4H.

• Does the transfer case shift motor rotate from the 2H Noposition to the 4H position? GO to L15.

L15 CHECK CIRCUITS 770 (WH), 771 (VT/YE), 772 (LB), 778 (OG)AND CIRCUIT 782 (BN/WH) FOR AN OPEN• Ignition OFF.• Disconnect: Transfer Case C350.• Disconnect: 4x4 Module (PCM) C175t.• Measure the resistance of the following circuits between 4x4

module (PCM) C175t, harness side and transfer case C350,harness side:

(Continued)

2005 F-150, 10/2004



(Continued)

Test Step Result / Action to TakeL15 CHECK CIRCUITS 770 (WH), 771 (VT/YE), 772 (LB), 778 (OG)

AND CIRCUIT 782 (BN/WH) FOR AN OPEN (Continued)

Circuit C175t C350

770 (WH) 6 5

771 (VT/YE) 7 1

772 (LB) 8 9

778 (OG) 9 13

782 (BN/WH) 46 10

YesGO to L16.NoREPAIR the circuit. CLEAR the DTC(s).

• Are the resistances less than 5 ohms? REPEAT the self-test.L16 CHECK CIRCUITS 770 (WH), 771 (VT/YE), 772 (LB), 778 (OG)

AND CIRCUIT 782 (BN/WH) FOR A SHORT TO VOLTAGE• Measure the voltage between the following circuits at 4x4

module (PCM) C175t, harness side and ground:

Circuit Pin

770 (WH) 6

771 (VT/YE) 7

772 (LB) 8

778 (OG) 9

782 (BN/WH) 46

YesREPAIR the circuit. CLEAR the DTC(s).REPEAT the self-test.No

• Is voltage present? GO to L17.

(Continued)

2005 F-150, 10/2004



(Continued)

Test Step Result / Action to TakeL17 CHECK CIRCUITS 770 (WH), 771 (VT/YE), 772 (LB), 778 (OG)

AND CIRCUIT 782 (BN/WH) FOR A SHORT TO GROUND• Measure the resistance between the following circuits at 4x4

module (PCM) C175t, harness side and ground:

Circuit Pin

770 (WH) 6

771 (VT/YE) 7

772 (LB) 8

778 (OG) 9

782 (BN/WH) 46


• Are the resistances greater than 10,000 ohms? REPEAT the self-test.L18 CHECK THE SHIFT MOTOR FOR AN INTERNAL SHORT TO

GROUND• Measure the resistance between shift motor C350 pins 1, 5, 9,

10, 13 component side and ground.

YesGO to L19.NoINSTALL a new transfer case shift motor.CLEAR the DTC(s). REPEAT the self-test,

• Is the resistance greater than 10,000 ohms? then GO to L29.L19 CHECK CIRCUITS 785 (BK/LG) AND 786 (RD) FOR POWER

DURING ACTIVE COMMANDS• Enter the active command mode on the diagnostic tool.

(Continued)

2005 F-150, 10/2004



(Continued)

Test Step Result / Action to TakeL19 CHECK CIRCUITS 785 (BK/LG) AND 786 (RD) FOR POWER

DURING ACTIVE COMMANDS (Continued)

• Enter the clockwise transfer case shift motor relay activecommand ON and OFF and measure the voltage betweentransfer case C350-15, circuit 786 (RD), harness side andground. Enter the counterclockwise transfer case shift motorrelay active command ON and OFF and measure the voltagebetween transfer case C350-14, circuit 785 (BK/LG), harnessside and ground.

YesINSTALL a new transfer case shift motor.CLEAR the DTC(s). REPEAT the self-test,then GO to L29.

• Are the voltages 9 volts or greater on the circuit being Nocommanded? GO to L20.

L20 CHECK THE CW/CCW RELAY CIRCUITS FOR VOLTAGE• Ignition OFF.• Disconnect: Clockwise (CW) Relay C1129.• Disconnect: Counterclockwise (CCW) Relay C1173.• Measure the voltage between CW motor relay C1129-86 and 87,

circuit 704 (DG/LG), harness side and ground.

YesGO to L21.

• Measure the voltage between CCW motor relay C1173-86 and No87, circuit 704 (DG/LG), harness side and ground. REPAIR the circuit. CLEAR the DTC(s).

• Is the voltage 9 volts or greater? REPEAT the self-test.

(Continued)

2005 F-150, 10/2004



(Continued)

Test Step Result / Action to TakeL21 CHECK THE CW/CCW RELAY GROUND CIRCUITS

• Measure the resistance between CW motor relay C1129-87a,circuit 57b (BK), harness side and ground.

YesGO to L22.

• Measure the resistance between CCW motor relay C1173-87a, Nocircuit 57a (BK), harness side and ground. REPAIR the circuit. CLEAR the DTC(s).

• Is the resistance less than 5 ohms? REPEAT the self-test.L22 CHECK CW/CCW RELAY CONTROL CIRCUITS

• Using the diagnostic tool active commands, command the motorto CW (low to high) and CCW (high to low).

• Measure the resistance between CW relay C1129-85, circuit 975(BN/YE) and ground; and between CCW relay C1173-85, circuit976 (OG) and ground when commanded to move CW (low to Yeshigh) or CCW (high to low). GO to L23.• Is pin 1 of the appropriate relay grounded (5 ohms or lessresistance) when the shift motor is commanded to move in Nothat direction? GO to L26.

L23 CHECK CIRCUIT 785 (BK/LG) AND CIRCUIT 786 (RD) FOR ANOPEN• Ignition OFF.• Disconnect: CW Motor Relay C1129.• Disconnect: CCW Motor Relay C1173.

(Continued)

2005 F-150, 10/2004



(Continued)

Test Step Result / Action to TakeL23 CHECK CIRCUIT 785 (BK/LG) AND CIRCUIT 786 (RD) FOR AN

OPEN (Continued)

• Measure the resistance between transfer case C350-14, circuit785 (BK/LG), harness side and CCW motor relay C1173-30,circuit 785 (BK/LG), harness side; and between transfer caseC350-15, circuit 786 (RD), harness side and clockwise motorrelay C1129-30, circuit 786 (RD), harness side.


• Are the resistances less than 5 ohms? REPEAT the self-test.L24 CHECK CIRCUIT 785 (BK/LG) AND CIRCUIT 786 (RD) FOR

SHORT TO POWER• Ignition ON.• Measure the voltage between transfer case C350-14, circuit 785

(BK/LG), harness side and ground; and between transfer caseC350-15, circuit 786 (RD), harness side and ground.


• Is voltage present? GO to L25.L25 CHECK CIRCUIT 785 (BK/LG) AND CIRCUIT 786 (RD) FOR

SHORT TO GROUND• Ignition OFF.

(Continued)

2005 F-150, 10/2004



(Continued)

Test Step Result / Action to TakeL25 CHECK CIRCUIT 785 (BK/LG) AND CIRCUIT 786 (RD) FOR

SHORT TO GROUND (Continued)

• Measure the resistance between transfer case C350-14, circuit785 (BK/LG), harness side and ground; and between thetransfer case C350-15, circuit 786 (RD), harness side andground.

YesINSTALL a new relay. CLEAR the DTC(s).REPEAT the self-test.NoREPAIR the circuit. CLEAR the DTC(s).

• Are the resistances greater than 10,000 ohms? REPEAT the self-test.L26 CHECK THE RELAY CONTROL CIRCUIT 975 (BN/YE) AND

CIRCUIT 976 (OG) FOR AN OPEN• Disconnect: 4x4 Module (PCM) C175b.• Measure the resistance between 4x4 module (PCM) C175b-14,

circuit 975 (BN/YE), harness side and CW motor relayC1129-85, circuit 975 (BN/YE), harness side; and between 4x4module (PCM) C175b-15, circuit 976 (OG), harness side andcounterclockwise motor relay C1173-85, circuit 976 (OG),harness side.


• Are the resistances less than 5 ohms? REPEAT the self-test.L27 CHECK CIRCUIT 975 (BN/YE) AND CIRCUIT 976 (OG) FOR A

SHORT TO GROUND• Ignition OFF.

(Continued)

2005 F-150, 10/2004



(Continued)

Test Step Result / Action to TakeL27 CHECK CIRCUIT 975 (BN/YE) AND CIRCUIT 976 (OG) FOR A

SHORT TO GROUND (Continued)

• Measure the resistance between 4x4 module (PCM) C175b-14,circuit 975 (BN/YE), harness side and ground; and between 4x4module (PCM) C175b-15, circuit 976 (OG), harness side andground.


• Are the resistances greater than 10,000 ohms? REPEAT the self-test.L28 CHECK CIRCUIT 975 (BN/YE) AND CIRCUIT 976 (OG) FOR A

SHORT TO POWER• Ignition ON.• Measure the voltage between 4x4 module (PCM) C175b-14,

circuit 975 (BN/YE), harness side and ground; and between 4x4module (PCM) C175b-15, circuit 976 (OG), harness side andground.


• Is voltage present? GO to L29.L29 ATTEMPT TO DUPLICATE THE CONCERN

• Inspect and, if necessary, clean the 4x4 module (PCM) and YesCW/CCW relays and connectors. INSTALL a new 4x4 module (PCM).

• Drive the vehicle and attempt to duplicate the concern. REFER to Section 303-04A for 4.6L• Is the concern still present? engine or Section 303-04B for 5.4L

engine. REPEAT the self-test.NoCLEAR the DTC(s). REPEAT the self-test.

L30 SHIFT THE TRANSFER CASE TO 4H MANUALLY• Remove the transfer case shift motor from the transfer case. Yes• Using a suitable wrench, rotate the shift cam to the 4H position. GO to L31.• Rotate the rear driveshaft and watch the front driveshaft. No• Does the transfer case shift to 4H and the front driveshaft REPAIR the transfer case. REFER torotates? Section 308-07B.

(Continued)

2005 F-150, 10/2004



(Continued)

Test Step Result / Action to TakeL31 CHECK THE TORQUE REQUIRED TO SHIFT THE TRANSFER

CASE• Rotate the shift cam by hand through 4L, N and 4H positions. Yes• Measure the torque required to perform the shift. GO to L32.• Is the torque required to shift 45 Nm (33 lb-ft) or less? No

REPAIR the transfer case. REFER toSection 308-07B.

L32 SHIFT THE TRANSFER CASE TO 2H MANUALLY• Rotate the shift cam to the 2H position. Yes• Rotate the rear driveshaft and watch the front driveshaft. GO to L33.• Does the transfer case shift to 2H and the front driveshaft Nodoes not rotate? REPAIR the transfer case. REFER to in

Section 308-07B.L33 SHIFT THE TRANSFER CASE TO 4L MANUALLY

• Rotate the shift cam by hand to the 4L position. Yes• Rotate the rear driveshaft and watch the front driveshaft. INSTALL a new 4x4 shift motor, then GO• Does the transfer case shift to 4L and the front driveshaft to L29.

rotates? NoREPAIR the transfer case. REFER toSection 308-07B.

Possible CausesPinpoint Test M: The Vehicle Does Not ShiftBetween 4H And 4L Modes Correctly • Transmission neutral switchNormal Operation • Brake ON/OFF switch (BOO)The high-low shift occurs when the reduction shift

• ABS wheel speed inputsfork moves the high-low collar to lock the planetary

• CAN communication networkgear set to the output shaft. The torque transmittedthrough the sun gear from the input shaft turns thefront planetary gear set assembly. The frontplanetary gear set assembly, now engaged, providestransfer case speed reduction. Certain criteria, suchas vehicle speed, transmission range selection andbrake applied must be met before this shift canoccur. Systematically check the necessary inputsand outputs of the 4x4 module (PCM), componentsof the transfer case, IWE components andhalfshafts.

PINPOINT TEST M: THE VEHICLE DOES NOT SHIFT BETWEEN 4H AND 4L MODES CORRECTLY

Test Step Result / Action to TakeM1 CHECK THE 2WD TO 4WD SHIFT

• Drive the vehicle and shift from 2WD to 4WD. Yes• Does the vehicle shift between 2WD and 4WD correctly? GO to M2.

NoGO to Pinpoint Test L.

M2 CHECK THE 4H TO 4L SHIFT• Drive the vehicle and shift MSS from 4H to 4L. Yes• Does the transfer case shift from 4H to 4L correctly and the Transmission neutral drag is excessive.

complaint is related to a clunk noise during the shift? REFER to Section 307-01 for transmissiondiagnosis.NoGO to M3.

(Continued)

2005 F-150, 10/2004


DIAGNOSIS AND TESTING (Continued)PINPOINT TEST M: THE VEHICLE DOES NOT SHIFT BETWEEN 4H AND 4L MODES CORRECTLY

(Continued)

Test Step Result / Action to TakeM3 CHECK THE TRANSMISSION, BRAKE ON/OFF (BOO) AND

WHEEL SPEED PIDS• Connect the scan tool. Yes• Ignition ON. If all three PIDS are accurate, GO to• A. Monitor the 4x4 module (PCM) transmission neutral PID while Pinpoint Test L.

shifting the transmission through gear ranges. No• B. Monitor the brake ON/OFF (BOO) switch PID while pressing A. REFER to Section 307-01 for furtherand releasing the brake pedal. diagnosis of the TR sensor and the CAN• C. Monitor the wheel speed PID. communication network.• A. Does the 4x4 module (PCM) transmission neutral PIDB. REFER to Section 206-09 for furtherindicate NEUTRAL when the transmission is shifted todiagnosis of the brake pedal positionNEUTRAL?switch and the CAN communicationB. Does the BOO switch PID agree with the actual brake network.pedal positions?C. REFER to Section 206-09 for furtherC. Do the wheel speed PIDs indicate 0 km/h (0 mph)? diagnosis of the ABS system and the CANcommunication network.

Possible CausesPinpoint Test N: 4WD Does Not Engage AtSpeed Correctly • Transfer case clutch coilNormal Operation • Transfer caseWhen the operator selects 4WD the 4x4 module

• 4x4 module (PCM)(PCM) engages a clutch for approximately 5

• Front axle assemblyseconds to synchronize the front and rear driveshaftsallowing a mechanical engagement of the transfer • Circuit 779 (BN)case. The 4x4 module (PCM) also removes the • Circuit 92 (LB/YE)ground path from the IWE solenoid, whichremoves vacuum from the IWEs, allowing them toengage the front axle shaft. Systematically check thenecessary inputs and outputs at the 4x4 module(PCM), internal components of the transfer case,IWE components and drive axles.

PINPOINT TEST N: 4WD DOES NOT ENGAGE AT SPEED CORRECTLY

Test Step Result / Action to TakeN1 RETRIEVE DTCs

• Connect the scan tool. Yes• Carry out the 4x4 module (PCM) self-test. If DTC 1826, GO to N15. If DTC 1824• Are any DTCs retrieved? and/or 1827, GO to N10. For all other

DTCs, GO to Symptom Chart.NoGO to N2.

N2 CHECK 4H ENGAGEMENT AT REST• Switch the MSS from 2H to 4H. Yes• While on the road, drive the vehicle in turns and check for GO to N3.

wind-up. No• Does 4H engage at rest correctly? GO to Pinpoint Test L.N3 CHECK 2H TO 4H SHIFT AT SPEED

• Switch the MSS to 2H.• Ignition ON.• Drive the vehicle and carry out a 2H to 4H shift while driving

approximately at 16 km/h (10 mph). Yes• Stop the vehicle, shift to 2H, drive the vehicle and carry out a GO to Pinpoint Test K.2H to 4H shift while driving at approximately 64 km/h (40 mph).• Does 4H engage correctly (or much better) at 16 km/h (10 No

mph) than at 64 km/h (40 mph)? GO to N4.

(Continued)

2005 F-150, 10/2004


DIAGNOSIS AND TESTING (Continued)PINPOINT TEST N: 4WD DOES NOT ENGAGE AT SPEED CORRECTLY (Continued)

Test Step Result / Action to TakeN4 CHECK THE TRANSFER CASE CLUTCH COIL LOCKUP

• Connect the scan tool.• Ignition ON.• Switch the MSS to 4H.• Using the diagnostic tool, command the transfer case clutch to

98 percent.• Raise and support the vehicle on a hoist. Refer to Section

100-02.• Remove the transfer case shift motor from the transfer case,

leaving the electrical connector connected. Yes• Using a suitable wrench, shift the transfer case shift cam to 2H. GO to N5.• Rotate the rear driveshaft while observing the front driveshaft.• Does the front driveshaft rotate when the rear driveshaft is No

rotated at 98 percent clutch capacity 30 Nm (86 lb-ft)? GO to N8.N5 CHECK THE TRANSFER CASE CLUTCH COIL RELEASE

• Using the diagnostic tool, command the transfer case clutch to 0 Yespercent. GO to N14.• Rotate the rear driveshaft while observing the front driveshaft.• Does the front driveshaft rotate when the rear driveshaft is No

rotated? GO to N6.N6 CHECK THE TRANSFER CASE SYNCHRONIZATION (ON A

HOIST)• Start the engine.• Place the transmission range (TR) selector in DRIVE and Yesincrease speed to between 16 km/h (10 mph) and 24 km/h (15 GO to N7.mph).• While observing the front driveshaft, switch the MSS to 4H. No• Did the front driveshaft start to spin? GO to N16.

N7 CHECK THE TRANSFER CASE DISENGAGEMENT• Shift to 2H. Yes• Rotate the rear driveshaft while observing the front driveshaft. GO to N16.• Did the front driveshaft rotate? No

GO to Pinpoint Test K.N8 CHECK CIRCUIT 779 (BN) FOR VOLTAGE

• Disconnect: Transfer Case C350.• While still active commanding 98 percent, measure the voltage

between transfer case C350-16, circuit 779 (BN), harness sideand the transfer case housing.

YesEnd the active command. INSTALL a newtransfer case synchronization clutch.REFER to Section 308-07B. CLEAR theDTC(s). REPEAT the self test.No

• Is the voltage greater than 9 volts? GO to N9.

(Continued)

2005 F-150, 10/2004



Test Step Result / Action to TakeN9 CHECK THE TRANSFER CASE CHASSIS GROUND

• While still in active command 98 percent, measure the voltagebetween transfer case C350-16, circuit 779 (BN), harness sideand chassis ground.

YesEnd the active command. REPAIR thetransfer case ground connection betweenthe transfer case and the chassis. CLEARthe DTC(s). REPEAT the self-test.No

• Is the voltage greater than 9 volts? End the active command. GO to N10.N10 CHECK CIRCUIT 779 (BN) FOR A SHORT TO GROUND

• Disconnect: 4x4 Module (PCM) C175t.• Measure the resistance between transfer case C350-16, circuit

779 (BN) and ground.

YesGO to N11.NoREPAIR the circuit. CLEAR the DTC(s).

• Is the resistance greater than 10,000 ohms? REPEAT the self-test.N11 CHECK CIRCUIT 779 (BN) FOR AN OPEN

• Measure the resistance between transfer case C350-16, circuit779 (BN), harness side and the 4x4 module (PCM) C175t-49,circuit 779 (BN), harness side.


• Is the resistance less than 5 ohms? REPEAT the self-test.

(Continued)

2005 F-150, 10/2004



Test Step Result / Action to TakeN12 CHECK CIRCUIT 92 (LB/YE) FOR A SHORT TO POWER

• Measure the voltage between transfer case C350-12, circuit 92(LB/YE), harness side and ground.


• Is voltage present? GO to N13.N13 CHECK CIRCUIT 92 (LB/YE) FOR AN OPEN

• Measure the resistance between transfer case C350-12, circuit92 (LB/YE), harness side and the 4x4 module (PCM) C175t-48,circuit 92 (LB/YE), harness side.


• Is the resistance less than 5 ohms? REPEAT the self-test.N14 CHECK CIRCUIT 779 (BN) FOR VOLTAGE

• While in active command greater than 10%, measure the voltagebetween transfer case C350-16, circuit 779 (BN), harness sideand ground.

YesEnd active command. GO to N15.NoEnd active command. INSTALL a newtransfer case synchronization clutch.REFER to Section 308-07B. CLEAR the

• Is voltage present? DTC(s). REPEAT the self-test.

(Continued)

2005 F-150, 10/2004



Test Step Result / Action to TakeN15 CHECK CIRCUIT 779 (BN) FOR A SHORT TO POWER

• While in active command 0%, measure the voltage betweentransfer case C350-16, circuit 779 (BN), harness side andground.


• Is voltage present? GO to N16.N16 CHECK FOR CORRECT 4x4 MODULE OPERATION

• Disconnect all 4x4 module (PCM) connectors. Yes• Check for: INSTALL a new 4x4 module (integral to

PCM). REFER to Section 303-14.— corrosion REPEAT the self-test.— pushed-out pins• Connect all 4x4 module (PCM) connectors and make sure they No

are seated correctly. The system is operating correctly at this• Operate the system and verify the concern is still present. time. Concern may have been caused by• Is the concern still present? a loose or corroded connector. CLEAR the

DTC(s). REPEAT the self-test.

Possible CausesPinpoint Test O: The 4x4 System Jumps OutOf Gear • IWE vent line(s)Normal Operation • Mode select switchOnce the 4x4 system engages the user selected

• Transfer casemode, that mode should be maintained. If the 4x4system does not stay in the selected positionsystematically check the 4x4 system components.

PINPOINT TEST O: THE 4x4 SYSTEM JUMPS OUT OF GEAR

Test Step Result / Action to TakeO1 CHECK FOR OBSTRUCTED IWE VENT LINES

• Raise and support the vehicle on a hoist. REFER to Section100-02.

• NOTE: The IWE vent port is the smaller of the 2 vacuum ports.YesDisconnect the LH IWE line from the vent port. INSTALL new IWE vent lines as• Attach a vacuum pump to the IWE vent line. necessary.• Attempt to draw and hold a vacuum. Repeat Steps 1, 2 and 3

for the RH side of the vehicle. No• Can a vacuum be held on either IWE vent line? GO to O2.

O2 VERIFY THE CONCERN• Drive the vehicle and attempt to duplicate the concern. Yes• Is the concern an uncommanded range shift (in or out of GO to O5.

low range)? NoGO to O3.

O3 CHECK THE MODE SELECT SWITCH (MSS) POSITION PIDS• Ignition OFF.• Connect the scan tool.

(Continued)

2005 F-150, 10/2004


DIAGNOSIS AND TESTING (Continued)PINPOINT TEST O: THE 4x4 SYSTEM JUMPS OUT OF GEAR (Continued)

Test Step Result / Action to TakeO3 CHECK THE MODE SELECT SWITCH (MSS) POSITION PIDS

(Continued)

• Ignition ON. Yes• Drive the vehicle. GO to O4.• Dynamically monitor the MSS PID while driving the vehicle ineach shift position. No

• Does the MSS PID always agree with the switch position? GO to Pinpoint Test L.O4 CHECK FOR DTCs

• Carry out the on-demand self test. Yes• Are DTCs present? REFER to the 4x4 module (PCM) DTC

Index.NoGO to Pinpoint Test Q.

O5 CHECK THE 4x4 INDICATORS• Stop the vehicle.• Transmission in NEUTRAL. Yes• Depress the brake pedal. GO to O3.• Observe the 4x4 indicators in the instrument cluster while cycling

through each MSS position. No• Do the 4x4 indicators match MSS switch positions? GO to O6.

O6 CHECK FOR DTCs• Transmission in PARK. Yes• Release the brake pedal. REFER to the 4x4 Module (PCM) DTC• Carry out the on-demand self test. Index.• Are DTCs present? No

CHECK the transfer case fluid level.REFER to Section 308-07B. If the fluidlevel is okay, CHECK for internal transfercase faults. REFER to Section 308-07B.

Possible CausesPinpoint Test P: Straightline DrivelineWind-up • Unmatched tire sizesNormal Operation • Unequal amounts of tire wearIn order for the 4WD system to function correctly,

• Unequal tire inflation pressurestires and wheels must be the same size, be in good

• Unmatched front and rear axle ratioscondition, and the front and rear axle ratios mustmatch.

PINPOINT TEST P: STRAIGHTLINE DRIVELINE WIND-UP

NOTE: 4x4 high/low (4H/4L) is not intended for driving on hard/dry surfaces.Test Step Result / Action to Take

P1 VERIFY THE CONCERN• Drive the vehicle and shift from 2H to 4H. There should be Yes

minimal wind-up in 4H mode during straight line maneuvers, GO to P2.(wind-up in turns is normal; 4x4 high/low is not intended for Nodriving on hard/dry surfaces). RETURN the vehicle to the customer.• Is excessive wind-up present? ADVISE about correct 4x4 system

operation and normal vehicle behavior.P2 CHECK FOR MATCHING WHEEL AND TIRE SIZES

• Check the wheel and tire sizes. Yes• Do the 4 wheel and tire sizes match? GO to P3.

NoADVISE the customer that 4x4 systemsrequire 4 matched, correctly inflated,correctly maintained tires to operatecorrectly.

(Continued)

2005 F-150, 10/2004


DIAGNOSIS AND TESTING (Continued)PINPOINT TEST P: STRAIGHTLINE DRIVELINE WIND-UP (Continued)

Test Step Result / Action to TakeP3 CHECK TIRE WEAR

• Check each of the 4 tires for wear. Yes• Are the 4 tires worn evenly? GO to P4.

NoADVISE the customer that 4x4 systemsrequire 4 matched, correctly inflated,correctly rotated tires to operate correctly.

P4 CHECK TIRE INFLATION PRESSURE• Check the inflation pressure in each tire. Refer to vehicle Yes

certification label. GO to P5.• Are the tire inflation pressures correct? No

ADJUST the tire pressure as necessary.TEST the vehicle for normal operation.ADVISE the customer that 4x4 systemsrequire 4 matched, correctly inflated,correctly maintained tires to operatecorrectly.

P5 CHECK THE FRONT AND REAR AXLE RATIOS• Check that front and rear axle ratios match. Refer to Section Yes

205-03. RETURN the vehicle to the customer and• Do the front and rear axle ratios match? ADVISE about correct 4x4 usage and

normal vehicle behavior.NoCHECK the vehicle identification label.INSTALL the correct axle(s). REFER toSection 205-00.

Possible CausesPinpoint Test Q: Electronic Shift On The Fly(ESOF) Functional Test • Transfer case and related componentsNormal Operation • IWE and related componentsWhen operating in 4-wheel drive, the transfer case

• Wheel/tire assembliesand both IWEs are locked. When in 4x4 low (4L),the transfer case low range gear set provides anadditional 2.64 gear reduction. When operating in2WD, the transfer case and both IWEs areunlocked.

PINPOINT TEST Q: ELECTRONIC SHIFT ON THE FLY (ESOF) FUNCTIONAL TEST

NOTE: 4x4 high/low (4H/4L) is not intended for driving on hard/dry surfaces.Test Step Result / Action to Take

Q1 CHECK FOR 4x4 INDICATOR PROVE OUT• Ignition OFF. Yes• Ignition ON. GO to Q2.• Do the 4x4 indicators illuminate at prove out? No

CHECK the instrument cluster for faults.REFER to Section 413-01.

Q2 CHECK 2WD OPERATION• Stop the vehicle. Yes• Transmission in NEUTRAL. GO to Q5.• Depress the brake pedal.• Switch the MSS to 2H. No• Do the 4WD indicators turn off? GO to Q3.

(Continued)

2005 F-150, 10/2004


DIAGNOSIS AND TESTING (Continued)PINPOINT TEST Q: ELECTRONIC SHIFT ON THE FLY (ESOF) FUNCTIONAL TEST (Continued)

Test Step Result / Action to TakeQ3 CHECK FOR DTCs

• Transmission in PARK. Yes• Release the brake pedal. REFER to the 4x4 Module (PCM) DTC• Connect the scan tool. Index for diagnosis.• Carry out the on-demand self test. No• Are DTCs retrieved? GO to Q4.

Q4 CHECK FOR WIND-UP IN 2WD• Drive the vehicle on a dry, hard surface while executing turns. Yes• Is wind-up present in turns? GO to Pinpoint Test M.

NoGO to Pinpoint Test R.

Q5 CHECK FOR WIND-UP IN 2WD• Drive the vehicle on a dry, hard surface while executing turns. Yes• Is wind-up present in turns? REPAIR the transfer case. REFER to

Section 308-07B.NoGO to Q6.

Q6 CHECK 4H OPERATION• Switch the MSS to 4H. Yes• Does the 4H indicator illuminate correctly? GO to Q9.

NoGO to Q7.

Q7 CHECK FOR DTCs• Transmission in PARK. Yes• Release the brake pedal. REFER to the 4x4 Module (PCM) DTC• Connect the scan tool. Index for diagnosis.• Carry out the on-demand self test. No• Are DTCs retrieved? GO to Q8.

Q8 CHECK FOR WIND-UP IN 4H• Drive the vehicle on a dry, hard surface while executing turns. Yes• Is wind-up present in turns? GO to Pinpoint Test R.


Q9 CHECK FOR 4H WIND-UP• Drive the vehicle on a dry, hard surface. Yes• Is straightline wind-up present? GO to Pinpoint Test P.

NoGO to Q10.

Q10 CHECK 4H WIND-UP IN TURNS• Drive the vehicle in 4H while turning. Yes• Is wind-up present in turns? GO to Q11.


Q11 CHECK 4L OPERATION• Bring the vehicle to a stop with the brake applied, transmission Yes

in NEUTRAL, switch the MSS to 4L. GO to Q14.• Does the 4WD low indicator illuminate correctly? No

GO to Q12.Q12 CHECK FOR DTCs


(Continued)

2005 F-150, 10/2004


DIAGNOSIS AND TESTING (Continued)PINPOINT TEST Q: ELECTRONIC SHIFT ON THE FLY (ESOF) FUNCTIONAL TEST (Continued)

Test Step Result / Action to TakeQ13 CHECK FOR WIND-UP IN 4L

• Drive the vehicle on a dry, hard surface while executing turns. Yes• Is wind-up present in turns? GO to Pinpoint Test R.

NoGO to Pinpoint Test M.

Q14 CHECK FOR 4L WIND-UP IN TURNS• Drive the vehicle on a dry, hard surface while executing turns. Yes• Is wind-up present and 4L functioning? GO to Q15.

NoCHECK for 4x4 module (PCM) DTC(s).REFER to the Inspection and Verificationprocedure in this section. IF no DTC(s)are present, GO to Pinpoint Test M.

Q15 CHECK 4L TO 2H SHIFT• With the vehicle at a stop, brake applied and transmission in Yes

NEUTRAL, switch the MSS from 4L to 2H. GO to Q18.• Do the 4WD indicators turn OFF? No

GO to Q16.Q16 CHECK FOR DTCs


Q17 CHECK FOR WIND-UP IN 2WD• Drive the vehicle on a dry, hard surface while executing turns. Yes• Is wind-up present in turns? GO to Pinpoint Test M.

NoGO to Pinpoint Test R.

Q18 CHECK FOR TRANSFER CASE DISENGAGEMENT• Raise and support the vehicle on a hoist. Refer to section Yes

Section 100-02. REFER to Section 308-07B.• Rotate the rear driveshaft while observing the front driveshaft. No• Does the front driveshaft rotate? GO to Q19.

Q19 CHECK FOR LH AND RH IWE DISENGAGEMENTNOTE: The engine must be at idle during the following steps tosupply vacuum for IWE engagement/disengagement.• Start the engine and allow to idle.• Rotate the left front tire one revolution forward and one

revolution backward while observing the left front halfshaft anduniversal joint. Yes• Rotate the right front tire one revolution forward and one GO to Pinpoint Test K.revolution backward while observing the right front halfshaft anduniversal joint. No

• Does the LH or RH front halfshaft rotate? GO to Q20.Q20 CHECK FOR IWE VACUUM LEAKS

• Ignition OFF.• Disconnect both vacuum lines from the IWE solenoid. Yes• Using a vacuum pump, apply 508 mm (20 in) Hg of vacuum to CHECK the IWE and related componentsthe IWE apply vacuum circuit. for leaks. GO to Pinpoint Test K.• Observe the vacuum reading.• Did the vacuum drop more than 25 mm (1 in) Hg per No

minute? GO to Q21.Q21 CHECK 2H TO 4H SHIFT AT SPEED ABOVE 32 KM/H (20 MPH)

• Switch the MSS to 2H. Yes• Drive the vehicle on the road and shift from 2H to 4H while The 4x4 system is functioning correctly.

driving above 32 km/h (20 mph). No• Does the transfer case shift to 4H satisfactorily? GO to Pinpoint Test N.

2005 F-150, 10/2004



Possible CausesPinpoint Test R: The Instrument Cluster 4LAnd 4H Indicators Do Not Operate • 4x4 system faultCorrectly/Do Not Operate/Flash

• CAN circuits:Normal Operation

— 1827 (WH/LG)The 4x4 high indicator status is transmitted to the— 1828 (PK/LG)instrument cluster from the 4x4 module (PCM)

through the controller area network (CAN), circuits • 4x4 module (PCM)1827 (WH/LG) and 1828 (PK/LG). A steady

• Instrument clusterindicator displays whether the vehicle is in 4x4LOW or 4x4 HIGH, according to the driverselection. Flashing 4x4 high and 4x4 low indicatorsis an indication that the instrument cluster has lostcommunication with the 4x4 module (PCM). Forinformation about CAN, refer to Section 418-00.

PINPOINT TEST R: THE INSTRUMENT CLUSTER 4L AND 4H INDICATORS DO NOT OPERATECORRECTLY/DO NOT OPERATE/FLASH

Test Step Result / Action to TakeR1 CHECK THE 4x4 INDICATOR PROVE-OUT

• Ignition OFF. Yes• Ignition ON. GO to R2.• Do the 4x4 indicators prove out correctly? No

CHECK the instrument cluster for faults.REFER to Section 413-00.

R2 CHECK FOR DTCs• Connect the scan tool. Yes• Carry out the on-demand self-test. REFER to the 4x4 Module (PCM) DTC• Are DTCs present? index for diagnosis.

NoGO to R3.

R3 CHECK THE INDICATORS IN 2H• Switch the MSS to 2H. Yes• Do any of the 4x4 indicator(s) illuminate? GO to R5.

NoGO to R4.

R4 CHECK THE INDICATORS IN 4H• Switch the MSS to 4H. Yes• Monitor the 4H instrument cluster indicator. GO to R6.• Does only the 4H instrument cluster indicator illuminate? No

GO to R7.R5 CHECK THE PIDS IN 2H

• NOTE: If it is difficult to read the motor position, use the activecommand to energize the transfer case motor contact plateposition return circuit.Monitor the IWE solenoid state PID and transfer case shift motorcontact plate PIDS in 2H.



4H OPEN CLOSED CLOSED OPEN YesCHECK the instrument cluster for faults.4L OPEN CLOSED OPEN CLOSEDREFER to Section 413-01.

• Do the PIDs indicate that IWE solenoid is energized (or ON) Noand that the motor is in the 2H position? GO to Pinpoint Test L.

(Continued)

2005 F-150, 10/2004


DIAGNOSIS AND TESTING (Continued)PINPOINT TEST R: THE INSTRUMENT CLUSTER 4L AND 4H INDICATORS DO NOT OPERATE

CORRECTLY/DO NOT OPERATE/FLASH (Continued)

Test Step Result / Action to TakeR6 CHECK THE INDICATORS IN 4L

• With the vehicle at a stop, brake applied and transmission in YesNEUTRAL, switch the MSS to 4L. The 4x4 indicators are operating correctly.

• Monitor the 4L instrument cluster indicator. CARRY OUT the electronic shift on the fly• Does only the 4L instrument cluster indicator illuminate? (ESOF) functional TEST. GO to Pinpoint

Test Q.NoGO to R8.

R7 CHECK THE PIDS IN 4H• Switch the MSS to 4H.• NOTE: If it is difficult to read the motor position, use the active

command to energize the transfer case motor contact plateposition return circuit.Monitor the IWE solenoid state PID and transfer case shift motorcontact plate PIDS in 4H.




• Do the PIDs indicate that IWE solenoid is de-energized (or NoOFF) and that the motor is in 4H position? GO to Pinpoint Test L.

R8 CHECK THE PIDS IN 4L• NOTE: If it is difficult to read the motor position, use the active

command to energize the transfer case motor contact plateposition return circuit.Monitor the IWE solenoid state PID and the transfer case shiftmotor contact plate PIDs in 4L.




• Do the PIDs indicate that IWE solenoid is de-energized (or NoOFF)? GO to Pinpoint Test M.

2005 F-150, 10/2004

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