essential characteristics of the obd family

Annex to partial model information document no.LZW6407BC5-E5 Annex D

Title: Essential characteristics of the OBD family Drawing no. :none Regulation : Directive :--- Type:LZW6407BC5-E5

SAIC GM Wuling Automobile Co., Ltd.

Essential characteristics of the OBD family

1 Make of OBD system : Continental Automotive(ChangChun) Co. Ltd.

2 Version of OBD system : NBFEU5

3 Engine

- Combustion process : Positive-ignition

- Method of engine fuelling : Manifold Port Injection

4 Emission control system

- Type of catalytic converter : Three-way

- Type of particulate trap : Not applicable

- Secondary air injection : Not applicable

- Exhaust gas recirculation : With EGR

5 OBD parts and functioning

The methods of OBD functional : See Annex D monitoring, malfunction diction and malfunction indication to the vehicle diver

6 Vehicles types within this family : N300, N300 MAX




Catalogue

1. Communication Protocol of OBD .............................................................................................. 41.1 Services Using KWP2000 Communication (All excepting EOBD) ........................................ 41.2 Services Using KWP2000 Communication (Only for EOBD) ................................................ 4

2. Description and Drawing of the MIL .......................................................................................... 53. Criteria for MI Activation and Deactivation ............................................................................... 54. List of all OBD Output Fault Codes ........................................................................................... 6

4.1 Table1-Diagnosis Trouble Code List and information ............................................................ 65．Manufacturer Declaration .......................................................................................................... 156. Security Mechanisms ................................................................................................................ 157. ANNEX-- General OBD working principles ............................................................................ 16

7.1 Catalyst Monitoring ............................................................................................................... 167.1.1 Legal Requirements ........................................................................................................ 167.1.2 General Description ........................................................................................................ 167.1.3 Catalyst diagnosis authorisation ..................................................................................... 18

7.2 Misfire Detection ................................................................................................................... 207.2.1 Misfire Detection Fade out conditions ............................................................................ 23

7.3 Fuel System Monitoring ........................................................................................................ 247.4 Oxygen Sensor Diagnosis ...................................................................................................... 277.5 Coolant Temperature Sensor Diagnosis ...................................... Error! Bookmark not defined.7.6 Canister Purge Solenoid Diagnosis ........................................................................................ 30

8. Additional information for the original type approval of the vehicle ...................................... 30




OVER VIEW

The engine management system consists of fuel injection system and ignition system. A serial of sensors are equipped. And their signals are basic information for EMS to control fuel injection and ignition.

The injection system is an internal part of the engine management system; the ignition system's function is to initiate combustion in the flammable air-fuel mixture by igniting it at precisely the right timing. Ignition coil produces sparks in each cylinder. Moreover, there are some control functions integrated including idle control, lambda closed loop control, knock control, lambda delay control, evaporative emission control and EGR control.

A tree-way catalyst is used for emission reduction. One binary upstream lambda sensor and one binary downstream lambda sensor are important parts for emission control.




1. Communication Protocol of OBD

1.1 Services Using KWP2000 Communication (All excepting EOBD) This specification is based on the on actual program version of Basic-Software. This implementation of diagnostic communication protocol KWP2000 is on Serial K line. This implementation and the description of diagnostic communication protocol

KWP2000 on kline is based on the following standards: ISO 14230-1:1997 Road vehicles - Diagnostic systems - Keyword Protocol 2000 – Part

1: Physical layer ISO 14230-2:1997 Road Vehicles - Diagnostic systems - Keyword Protocol 2000 – Part

2: Data link layer VDA / WD 14230-3: 1997 Keyword Protocol 2000 - Part 3 Implementation VDA - Recommended Practice ISO 14230-4 Road vehicles - Keyword protocol 2000 for

diagnostic systems – Part 4: Requirements for emission-related systems

Applicability Applicability Applicability Applicability OSI 7 layer OSI 7 layer OSI 7 layer OSI 7 layer EmissionsEmissionsEmissionsEmissions----related diagnostics related diagnostics related diagnostics related diagnostics

Seven layer

according

to ISO/IEC

7498 and

ISO/IEC

10731

Physical (layer 1) ISO 14230-1

Data link (layer 2) ISO 14230-2

Network (layer 3) ---

Transport (layer 4) ---

Session (layer 5) ---

Presentation (layer

6)

---

Application (layer

7)

ISO/DIS 15031-5 ISO 14230 – 4 and ISO 14230-3

1.2 Services Using KWP2000 Communication (Only for EOBD) �This set of specification provides the implemented diagnostic protocol functionality in the project.

�This implementation and the description of diagnostic communication protocol are based on the following standards:




Standard Name Standard Name Standard Name Standard Name Description Description Description Description

ISO/DIS 15031-5:2006-01-15 Road Vehicles – Communication between vehicle and external equipment for emission related diagnostics

Part 5:Emission-related diagnostic services

SAE J1979 May 2007: This document supersedes SAE J1979 2007-04 draft edition,

and is technically equivalent to ISO 15031-5:2006, with the

addition of new capabilitiesrequired by revised

regulations from the California Air Resources Board

2. Description and Drawing of the MIL

Legislation requires the display of faults relevant to exhaust emissions by a fault lamp (MIL) in the dash board. For check engine or error, it should display the following sign when triggered:

3. Criteria for MI Activation and Deactivation

The MIL must illuminate for Key-ON and standing engine for functional control. For detected faults which are relevant to exhaust emissions and the emission exceeds the legally permission, the MIL must illuminate. For special faults (e.g. detection of misfire rates damaging the catalyst), the MIL must blink immediately with 1 Hz. The MIL may extinguish after the legally permissible debouncing of healing, following detected healing of all faults.

There are two types of the MIL activation criteria: -type A: illuminate MI when the failure occurs one time. -type B: illuminate MI when the failure occurs at two consecutive trips. Remark：A trip means a driving cycle in which all the OBD diagnosis can be completed. For EOBD, it can be based a Euro-Ⅳ emission test cycle . The extinguishment of MIL：

In 3 continuous trips, if there is no more failure is detected by the function which cause MIL-on, and no other fault to illuminate the MI too, the MIL extinguishes.




To clear Fault Code: If a fault is not been detected in consecutive 40 warm-up drive cycle, the OBD system will clear the fault code and the freeze frame.

4. List of all OBD Output Fault Codes

4.1 Table1-Diagnoses Trouble Code List and information

DTC Description Light ON CYC

OFF CYC

P0031 Upstream oxygen heater 1 short to ground or line break YES 2 3

P0032 Upstream oxygen heater 1 short to battery YES 2 3

P0036 Downstream oxygen heater Resistance diagnosis resistance

out of limits NO nun nun

P0645 A/C Clutch Relay Control Circuit-Open Circuit NO N/A N/A

P0646 A/C Clutch Relay Control Circuit-Short to Ground NO N/A N/A

P0647 A/C Clutch Relay Control Circuit-Short to Battery NO N/A N/A

P0325 Knock Sensor Circuit-Knock acquisition chain diagnosis error YES 2 3

P0325 Knock Sensor Circuit-Basic knock signal diagnosis error YES 2 3

P0504 Brake Switch Signal Correlation Implausible NO N/A N/A

P0341 Intake Camshaft Period out of Range NO N/A N/A

P0341 Intake camshaft signal plausibility NO N/A N/A

P0016 Intake Camshaft Position out of Range YES 2 3

P0011 Enduring Intake Camshaft Position Deviation At Steady

Setpoint YES 2 3




P0341 Intake camshaft diagnostic for engine synchronization YES 2 3

P0340 Intake Camshaft For Engine Synchronization Implausible YES 2 3

P0420 Catalyst System Efficiency Below Threshold YES 2 3

P0336 crankshaft signal missing YES 2 3

P0336 crankshaft signal implausible YES 2 3

P0336 crankshaft synchronization lost YES 2 3

P0373 Crankshaft Signal Implausible YES 2 3

P0373 crankshaft tooth period out of range YES 2 3

P0691 Cooling Fan Relay 1 Open Circuit YES 2 3

P0691 Cooling Fan Relay 1 Short to Ground YES 2 3

P0692 Cooling Fan Relay 1 Circuit -Short to Battery YES 2 3

P0693 Cooling Fan Relay 2 Open Circuit YES 2 3

P0693 Cooling Fan Relay 2 Short to Ground YES 2 3

P0694 Cooling Fan Relay 2 Circuit -Short to Battery YES 2 3

P2413 EGR valve sensor adaptation error YES 2 3

P0488 EGR position control error YES 2 3

P0487 EGR valve power stage diagnosis open circuit YES 2 3

P0489 EGR valve power stage diagnosis short circuit ground YES 2 3

P0490 EGR valve power stage diagnosis short circuit plus YES 2 3




P0444 Evap. Emission Control System - Purge Control Valve Circuit YES 2 3

P0458 Evap. Emission Control System - Purge Control Valve Circuit

-Short to Ground YES 2 3

P0459 Evap. Emission Control System - Purge Control Valve Circuit

-Short to Battery YES 2 3

P0113 Intake Air Temperature Sensor Circuit High YES 2 3

P0112 Intake Air Temperature Sensor Circuit -Short to Ground YES 2 3

P2100 ETC open circuit YES 1 3

P2101 ETC Overheat Protection YES 1 3

P2100 ETC Short Circuit YES 1 3

P0638 ETC Position Controller Output 1 Implausible YES 1 3

P0639 ETC Position Controller Output 2 Implausible YES 1 3

P0133 Upstream Oxygen Sensor Slow Response YES 2 3

P0171 System Too Lean-Bank 1 YES 2 3

P0172 System Too Rich-Bank 1 YES 2 3

P0171 System Too Lean-Bank 1 YES 2 3

P0172 System Too Rich-Bank 1 YES 2 3

P0351 Ignition Coil A Circuit YES 2 3

P0352 Ignition Coil B Circuit YES 2 3

P0353 Ignition Coil C Circuit YES 2 3

P0354 Ignition Coil D Circuit YES 2 3




P2300 Ignition Coil A Circuit Low YES 2 3

P2303 Ignition Coil B Circuit Low YES 2 3

P2306 Ignition Coil C Circuit Low YES 2 3

P2309 Ignition Coil D Circuit Low YES 2 3

P2301 Ignition Coil A Circuit -Short to Battery YES 2 3

P2304 Ignition Coil B Circuit -Short to Battery YES 2 3

P2307 Ignition Coil C Circuit -Short to Battery YES 2 3

P2310 Ignition Coil D Circuit -Short to Battery YES 2 3

P0506 Idle Speed Control too Low NO N/A N/A

P0507 Idle Speed Control too High NO N/A N/A

P0201 Cylinder 1 Injector Circuit YES 2 3




P0261 Cylinder 1 Injector Circuit Low YES 2 3




P0262 Cylinder 1 Injector Circuit High YES 2 3







P2096 Fuel trim diagnosis - maximum limit of trim controller reached NO N/A N/A

P2097 Fuel trim diagnosis - minimum limit of trim controller reached NO N/A N/A

P0037 O2 Heater Control Circuit -Open or Short Circuit (Bank1

Sensor2) YES 2 3


Sensor2) YES 2 3

P0038 O2 Heater Control Circuit -Short to Battery (Bank1 Sensor2) YES 2 3


Sensor1) YES 2 3

P0031 O2 Heater Control Circuit -Open or Short Circuit (Bank1 Sensor1)

YES 2 3

P0032 O2 Heater Control Circuit /(Bank1 Sensor1)Short circuit to battery YES 2 3

P0106 Manifold air pressure sensor signal Implausible YES 2 3

P0107 Manifold air pressure sensor signal short to ground YES 2 3

P0108 Manifold air pressure sensor signal short to battery voltage YES 2 3

P0606 microcontroller communication fault NO N/A N/A

P0650 MIL Lamp circuit Open circuit NO N/A N/A

P0650 MIL Lamp circuit Short Circuit to Ground NO N/A N/A

P0650 MIL Lamp circuit Short Circuit to Battery NO N/A N/A

P0301 Misfire 0 (Cylinder #1) YES 2 3







P0300 Multiple Misfire YES 2 3

P060A General monitoring error YES 1 3

P060C Processor Monitoring Failure YES 1 3

P061C Internal Control Module Engine RPM Performance YES 1 3

P0141 O2 sensor (down) heater plausibility diagnose YES 2 3

P0135 O2 sensor (up) heater plausibility diagnose YES 2 3

P0136 Downstream Oxygen Sensor Circuit YES 2 3

P0130 Upstream Oxygen Sensor Circuit YES 2 3

P2120 Acceleration pedal disconnection diagnosis YES 1 3

P2299 Brake Pedal Position/Accelerator Pedal Position Incompatible YES 2 3

P2123 Pedal Position Sensor 1 Circuit High Input YES 2 3

P2128 Pedal Position Sensor 2 Circuit High Input YES 2 3

P2122 Pedal Position Sensor 1 Circuit Low Input YES 2 3

P2127 Pedal Position Sensor 2 Circuit Low Input YES 2 3

P2138 Pedal Position Sensor 1/2 Voltage Implausible Correlation YES 2 3

P0134 Upstream Oxygen Sensor not ready YES 2 3




P0325 Knock Sensor Circuit-Relative knock signal diagnosis error YES 2 3

P0627 Fuel Pump Relay Circuit YES 2 3

P0628 Fuel Pump Relay Circuit Low YES 2 3

P0629 Fuel Pump Relay Circuit -Short to Battery YES 2 3

P0685 Main Relay Circuit Open Circuit NO N/A N/A

P0686 Main Relay Circuit Short to Ground NO N/A N/A

P0687 Main Relay Circuit Short to Battery NO N/A N/A

P0137 Downstream Oxygen Sensor Circuit Low YES 2 3

P0131 Upstream Oxygen Sensor Circuit Low YES 2 3

P0138 Downstream Oxygen Sensor Circuit -Short to Battery YES 2 3

P0132 Upstream Oxygen Sensor Circuit -Short to Battery YES 2 3

P0315 Flywheel Segment Adaptation At The Limit NO N/A N/A

P0075 Intake IVVT Solenoid Valve Circuit YES 2 3

P0076 Intake IVVT Solenoid Valve Circuit Low YES 2 3

P0077 Intake IVVT Solenoid Valve Circuit -Short to Battery YES 2 3

P1315 Engine roughness segment time acquisition error NO N/A N/A

P0537 A/C Evaporator Temperature Sensor Circuit Low NO N/A N/A

P0538 A/C Evaporator Temperature Sensor Circuit High NO N/A N/A

P0117 Coolant Temperature Sensor Circuit Low YES 2 3




P0118 Coolant Temperature Sensor Circuit High or Circuit YES 2 3

P0119 Coolant Temperature Sensor TCO Gradient Failure YES 2 3

P0016 Intake Camshaft Drift of Position NO N/A N/A

P2176 lower position not reached YES 1 3

P2176 lower mec. stop adaptation outside range YES 1 3

P2176 error lower return spring check YES 1 3

P2176 adaptation conditions exceeded YES 1 3

P2176 limp-home adaptation outside range YES 1 3

P2176 Upper position not reached YES 1 3

P2176 error upper return spring check YES 1 3

P2118 ETC position sensor difference symptom; System deviation outside the valid range YES 1 3

P0121 Throttle Position Sensor 1 Signal Implausible YES 1 3

P0221 Throttle Position Sensor 2 Signal Implausible YES 1 3

P2135 Throttle Position Sensor1/2 Voltage Correlation Implausible YES 1 3

P061A Internal Control Module Engine Torque Performance YES 1 3

P061B Actual or Requested Torque Higher Than Allowed Limit YES 1 3

P0643 Sensor Reference Voltage 0 Circuit High YES 1 3

P0642 Sensor Reference Voltage 0 Circuit Low YES 1 3

P0653 Sensor Reference Voltage 1 Circuit High YES 1 3




P0652 Sensor Reference Voltage 1 Circuit Low YES 1 3

P0406 Voltage of EGR valve actuator position sensor high YES 2 3

P0405 Voltage of EGR valve actuator position sensor low YES 2 3

P0563 Battery voltage too high NO N/A N/A

P0563 Battery voltage too high NO N/A N/A

P0562 Battery voltage too low NO N/A N/A

P0562 Battery voltage too low NO N/A N/A

P0123 Throttle Position Sensor 1 circuit High Input YES 2 3

P0122 Throttle Position Sensor 1 circuit Low Input YES 2 3

P0223 Throttle Position Sensor 2 circuit High Input YES 2 3

P0222 Throttle Position Sensor 2 circuit Low Input YES 2 3

P0500 Vehicle Speed Sensor Signal Implausible YES 2 3

P2158 Wheel Speed Sensor Signal Implausible NO N/A N/A




5．．．．Manufacturer Declaration

3% misfires will cause the emission exceed OBD limit in Type I test cycle.

Following misfire rate can cause damaged of catalytic converter. Misfire Rate (%)

N/load mis 30 40 50 60 80 100 992 25.0 25.0 25.0 25.0 25.0 20.0

2000 20.0 25.0 20.0 20.0 20.0 12.5

3000 20.0 20.0 16.7 16.7 12.5 10.0

3500 20.0 16.7 14.3 11.1 6.7 8.3

4000 14.3 14.3 12.5 9.1 8.3 7.1

4500 16.7 14.3 12.5 9.1 6.7 5.9

6. Security Mechanisms

The effects resulting from user actions during a reprogramming session or caused by unauthorized manipulation are not predictable. So a protection is necessary to avoid erroneous flash contents as a consequence of such an influence. Checksum calculation The software is divided into four parts: 1、Boot-SW，2、ECU-SW，3、Calibration Data，4、Volcano. To guaranty the validity of the reprogrammed data transmitted through the communication line an independent checksum value is stored in each area (ECU-SW, Calibration data, Volcano). This checksum is tested at the end of a reprogramming session. If the calculated values do not fit with the stored values in ECU-SW area, Calibration data area or Volcano area, the applicative software is inhibited and there is no engine operation. Coherence System The Coherence System ensures that the four independent SW-parts fit together. The coherence identifiers are implemented in the Boot-SW, the ECU-SW, the Calibration data and Volcano and are checked at the end of a reprogramming session and at start-up of the ECU. If the four identifiers do not fit together, the applicative software is inhibited and there is no engine operation.




7. ANNEX-- General OBD working principles

7.1 Catalyst Monitoring

7.1.1 Legal Requirements

The diagnostic must monitor the performance of the catalyst system. An Error exists if the exhaust emissions increase above the EOBD threshold over the emission drive cycle.

7.1.2 General Description

Solution chosen to fulfill OBD’s requirement is based on Oxygen Storage Capacity (OSC):

During a controlled stimulus (special A/F pulses in engine steady state conditions); the downstream O2 sensor signal is analyzed to evaluate the OSC of the catalyst.

The OSC is correlated experimentally with the global HC efficiency and HC emission during cycle. It represents the quantity of oxygen that is really used for the oxidation-reduction reaction by the catalytic converter (stored in lean excursion and consumed in the rich excursion).

Description of the open loop diagnosis Catalyst monitoring is a sequential diagnosis made on steady state conditions and this monitoring is intrusive.

Three phases are composing the diagnosis:

Engine stabilization Controlled stimuli – stabilisation Controlled stimuli – diagnosis

If a problem has occurred with the downstream sensor during the catalyst diagnosis, a sensor diagnosis is done.




During the ‘Controlled stimuli – diagnosis phase’ the downstream sensor activity is measured and corresponds to the OSC of the catalyst. If this activity is high (low OSC) the diagnosis criteria is high.

If one of the monitoring conditions is not met or if the mass air flow deviates too much from the value stored at the start of this test phase, the test is interrupted and the system returns to the “out of diagnosis “state.

New cat Good limit cat

Bad limit cat

Damage cat

Limit cat Failure threshold

Down sensor dynamic (DOWN_DYN_CAT)

Emission threshold




Downstream sensor diagnosis phase:

If throughout the Controlled Stimuli phase, repeated several times, the downstream sensor has not moved, the A/F closed loop mode is delayed in order to test the sensor.

If the downstream sensor sends a signal indicating a rich (lean) mixture), the injection time is forced to lean (rich) until the sensor switches over or until the end of a delay. If this delay expires, the sensor is treated as failed. The following reasons may apply:

A leak in the exhaust line, A damaged sensor.

Electrical failure (short circuit and open circuit of signal and heater are treated as comprehensive components .

If the catalyst diagnosis has been done without any problem, the downstream sensor is treated as “ good ”and a sensor diagnosis is not required.

If monitoring conditions for the diagnosis are fulfilled, the system informs the OBD sequencer and waits for its authorization to start catalyst diagnosis. The OBD sequencer manages the priorities in case of multiple diagnosis requests (catalyst diagnosis and O2 sensor diagnosis).

7.1.3 Catalyst diagnosis authorisation

If the monitoring conditions for the diagnosis are fulfilled, the system informs the OBD sequencer and waits for its authorization to start catalyst diagnosis. The OBD sequencer manages the priorities in case of multiple diagnosis requests (catalyst diagnosis and O2sensor diagnosis). The EVAP re-circulation has to be stopped when a catalyst diagnosis is requested, unless evaporative re-circulation gets priority in the case of very high canister load.

Monitoring conditions:

No stored failure on misfiring type A or B4, No stored failure for the coolant temperature sensor. No stored failure for the air temperature sensor.




No stored failure for the crank senor signal, No stored failure for the camshaft sensor signal, No stored failure for the Throttle position sensor, No stored failure for the Fuel System, No stored failure for the upstream and downstream O2 sensors signal, No stored failure for the upstream and downstream O2 sensors heating, No stored failure for the manifold air pressure sensor, No stored failure for canister purge solenoid valve, The condition for the A/F closed loop are met (LV_LSCL_i) The condition for engine temperature is met (hot engine) MAF criteria are met : window and stability Engine speed window Vehicle speed window The condition for catalyst temperature is met (based on temperature model). Altitude is lower than 2500m.




7.2 Misfire Detection

Legal requirements

The diagnosis must monitor the engine for misfiring. If misfiring is detected, the cylinder (s) that has (have) misfired must be identified. An error condition exists, if misfire rates occur in the monitoring ranges which result in damage to the catalyst or increase exhaust emissions to values above the EOBD thresholds

General Description

The system checks for misfiring by monitoring the crankshaft acceleration. Misfiring causes the angular velocity of the crankshaft to drop in an angular range specific to the cylinder in question. The misfiring detection is based on the observation of this variation of segment period (180° CRK).

To compute an engine roughness value, 5 continuous valid segments are required for a 4 cylinder engine.

Main causes of misfire: injector shut off, fuel pressure problems, fuel combustion problems, ignition cut off….

Strategy description

Segment period correction




The prerequisite for reliable misfire detection is accurate segment period measurement. However, the period between two TDC, at constant speed, is subject to variations due to manufacturing tolerances and off centre installation. These inaccuracies are systematic, so they can be “learned “during fuel cut off periods and used for compensation. By this way, the systematic error introduced by the tolerances of the target wheel is largely eliminated. Misfire Algorithm




OBD statistic flowchart

Misfiring threshold

The irregular (misfiring) engine roughness values computed from the segment periods measured and corrected are compared to load and engine speed dependent thresholds THD_ER. If |ER| > |THD_ER| => a single misfire event is detected.

Threshold determination THD_ER: the threshold is influenced mainly by the engine speed and load. Other influencing parameters are the engine temperature and the target wheel learning degree, thus the threshold is corrected in cold coolant temperature conditions, and until a first flywheel learning is complete.




7.2.1 Misfire Detection Fade out conditions

The misfire is monitored continuously, except in low engine speed and load:

Variation in the engine torque caused by other phenomenon than misfiring is recognised in order to inhibit misfire monitoring (fade out conditions) temporary:

Maximum air mass gradient too large Maximum throttle gradient too large Ignition retardation without change limitation. e.g. Gear shift Air conditioning compressor activation Rough road detection Traction Control activation.

Furthermore, the detection has to be suppressed in case of:

Failure on Manifold Air Pressure sensor, Failure on Throttle position sensor, Failure on Crank signal sensor, Failure on Cam signal sensor Failure on Main Relay Failure on Battery Voltage




7.3 Fuel System Monitoring

General Overview

The fuel system diagnosis shall monitor the fuel delivery system for its ability to provide compliance with emission standards.

The fuel system diagnosis checks if the sum of short-term fuel trim (only based on upstream sensor voltage monitoring) and long term fuel trim (one additive & one multiplicative term) are within a band.

Out of this band a failure is detected.

Different fuel system problems may occur:

Fuel pressure problem: short term fuel trim deviation which induces emissions problem, but no effect on the catalyst window set point because of homogenous mixture, in steady engine conditions. Cylinder misdistribution problem due to injector failure: short-term fuel trim deviation with effect on the catalyst window set point because non-homogeneous mixture.

Example: lean engine




LAM_MAX = restriction for rich limit LAM_MIN = restriction for lean limit C_FAC_LAM_MAX = LAM_MAX_FSD C_FAC_LAM_MIN = LAM_MIN_FSD




Fuel system monitors Authorisation

This diagnosis is continuously performed if entry conditions are fulfilled.

Engine Speed Mass Airflow Coolant temperature Intake air temperature Ambient Pressure Closed Loop Fuel Control

Detection is suppressed in case of the following failures

Type A or B Misfire detected Failure on Manifold Air Pressure sensor, Failure on Intake Air Temperature sensor Failure on Engine Coolant temperature sensor Failure on Canister Purge solenoid Failure on Electronic Throttle, Failure on Crank signal sensor, Failure on Cam signal sensor Failure on Ignition Coil Failure on Oxygen sensors




7.4 Oxygen Sensor Diagnosis

Legal requirements

In order to meet the legal requirements for EOBD oxygen sensor diagnosis, the oxygen sensor switching times and therefore the control frequency of the oxygen control must be monitored in addition to the standard oxygen sensor diagnosis functions. An error condition of the oxygen sensors upstream from the catalyst exists when the response times exceed the defined limits, thereby causing one of the exhaust emissions to exceed the EOBD limit.

General Description

The upstream sensor will cause emission increase when its response time increases too much (A/F Loop period or frequency check).




The rich and lean dwell times are evaluated to check the oxygen sensor control frequency. This is then compared to the limits for the maximum rich and lean dwell times are derived from a map of engine speed versus load.

The oxygen sensor is ok when the oxygen controller dwell period measured in the rich or lean range is below the corresponding limit.

Oxygen Sensor Monitor Authorisation:

no stored failure on misfiring type A and B4, no stored failure for the coolant temperature sensor, no stored failure for the crank sensor signal, no stored failure for the camshaft sensor signal, no stored failure for the Throttle position sensor, no stored failure for upstream O2 sensors signal electrical, no stored failure for the upstream O2 sensors heating, no stored failure for the downstream O2 sensor heating, no stored failure for the manifold air pressure sensor, no stored failure on Canister Purge solenoid the conditions for the A/F closed loop are met The condition for engine temperature is met (hot engine) O2 sensor heating ready and in normal operating rate, Canister load stabilised Mass Airflow window Engine speed window Vehicle speed window The condition for catalyst temperature is met (based on temperature model). Altitude lower than 2500m

Oxygen Sensor Monitor Flow Chart




7.5 Canister Purge Solenoid Diagnosis

Electrical Canister Purge Solenoid Diagnosis (CPS) The purpose is to diagnose electrical errors detected by the hardware (depending of output driver used). The signal for evaporative emission control valve is pulse-width modulated.

If the corrected PWM signal for CPS opening exceeds the minimum threshold for SCB diagnosis window, then “Short circuit to battery” fault is detected. If the corrected PWM signal for CPS opening exceeds the maximum threshold for SCG diagnosis window, then “Short circuit to Ground” fault is detected. If the corrected PWM signal for CPS opening exceeds the minimum threshold for OC diagnosis window, then “Open Circuit” fault is detected.

8. Additional information for the original type approval of the

vehicle

Component Fault

code

Monitoring

strategy

Fault detection

criteria

MI

activation

criteria

Secondary

parameters

Pre

conditioning

Demo

nstrati

on test

Catalyst Out

of emission

P0420 Oxygen

sensor 1 and

2 signals

Difference

between sensor

1 and 2 signals

3rd Type I

cycle

Engine speed,

engine load,

A/F ratio,

catalyst

temperature

Two Type I

cycles

Type I

Multiple

Misfire

Misfire0(cyli

nder#1) to

misfire(cylin

der#4)

P0300

to

P0304

Fluctuation

of crankshaft

speed.

Change of

segment time

3rd Type I

cycle

Camshaft

signal, engine

speed, engine

load

Two Type I

cycles

Type I

Upstream

oxygen

sensor 1

P0133 O2 sensor 1

signal

Difference

between lean

and rich time of

3rd Type I

cycle

A/F mode,

engine speed,

engine load

Two Type I

cycles

Type I




Slow

response

sensor

Canister

Purge

Solenoid line

break

P0444 Circuit check Open circuit 3rd Type I

cycle

Ignition switch

on

Two Type I

cycles

Type I

essential characteristics of the obd family

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