Clean Brakes Mean Less Chance For Noise; Brake noise is high on the list of many customer brake complaints. Often this noise is a result of something built in by the tech performing the brake reline. Improper cleaning and preparation of brake drums, and greasy smudges on new brake linings almost always results in a noise the customer returns to complain about. Take some masking tape and apply it to the linings before assembly. Then remove the tape when you’re ready to reinstall the drum. Don’t forget to clean the drum. (Notice the masking tape on the brake shoe in the picture to the right?). - Ray Grooms Ford Diesel Scan Tool Parameter Quick Checks; Check KOEO (Key On Engine Off) MAP, EP, and Baro, (Manifold Absolute Pressure, Exhaust Pressure, and Barometric Pressure) all should read approximately the same as pressure is equalized when the engine is not running (within 1.5 psi of each other). During cranking try graphing the ICP and IPR (Injector Control Pressure and Injector Pressure Regulator). ICP should reach a minimum of 500psi during crank-ing and climb above 725psi within 6 -15 seconds of cranking. Normal IPR values would be be-low 30% during idle and approximately 14% during cranking. IPR values can range from 7% to 65%. - Eric Irwin Exhaust Backpressure (EBP) Sensor KOEO & KOER Normal Values; The EBP sensor is a critical input for the DPF monitoring system. EBP is given in millibars and a normal KOEO value is 2mbar, KOER (idle) would be approximately 8mbar. A high KOER reading indicates excessive backpressure, restrictions in the exhaust system are likely at fault. Low readings indicate a lack of backpressure and / or reference line damage. DPF Monitoring systems will typically illuminate the DPF warning indicators if EBP stays above 180mbar for longer than 36 seconds. - Sal Guerrero

Scope It!: Injection, Conventional Negatively Saturated Injector

Scope Settings; Channel A is measuring injector current, select the 60A Amp Probe and use the 20A mode option. Channel B is being used to measure injector voltage, select the x20 probe and be sure to install the 20:1 attenuator (injectors have an inductive kickback, attenuation is necessary to avoid potential damage). Set the Channel A range to +/- 5a and Channel B range to +/- 100v. A time base of 1ms per division with a repeat trigger will give you 1 injection event, setting the scope to a longer time base, like 200ms, is more prefer-able as you can use the windowed zoom tool to analyze the waveform in greater detail. Measuring the Injector Waveform; Make sure the 60A clamp is zeroed prior to clamping it around the injector wiring. Clamp the Amp Probe around either of the 2 wires at the injec-tor, if the waveform is upside down, flip the amp clamp around for correct polarity. With the red scope lead back probe the switched side of the injector ct. at the injector connector (the conventional negatively saturated injector is a ground switched injector). Install an alliga-tor clip onto the scope’s black lead and install it at the negative battery post (these injectors are measured between the switched ground control and battery negative). Key Points; Point A shows the source voltage (red trace) which should be B+. Point B is the ground offset and between Points B and D is the injector on-time. Injec-tor control usually ranges from 2.5ms to 16ms, depending on eng. size, 2.5-5ms is common at idle. Point C shows the injector amperage (usually .5-.75a), the hump is the point where the injector physically opens. Point E is the inductive spike created when amperage is turned off. In this capture the kickback voltage is at 40v, others can reach as high as 120v or more. Point F shows the physical closing of the injector. When both the injector’s volts and amps are meas-ured we get a fuller picture of what is going on, however not all injectors will show the action of the injector pintle as it opens and closes. This may be normal and varies between different injectors. Other injector types include; Peak and Hold, and Pulse Width Modulated Injectors. - Eric Irwin

Tech Tips!

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Newsletter Editors Eric Irwin

Ray Grooms Sal Guerrero

Announcements • Factory Ford diesel tech books & Motor article now in the Tech Tips folder on the Y drive!

• Tech Tips needed! Have them published and share with everyone!

4

ICP and IPR respond correctly during startup and test drive. Initial ICP

reached 1250psi, IPR at 14% (KOEO), 55% during hard acceleration (KOER),

& 24% at idle. ICP reaches 2,500 psi during the test drive.

The masking tape en-sures the brake linings remain clean and “like new” while you com-plete the related brake work.

A B

C

E

F

D

Technician Recognition Bart Matson; Bart fixed a Suburban that had been in the shop multiple times for an intermittent P0102, Bart found that the 2-way radio was causing MAF signal interference and setting the P0102 intermittently,

the problem would occur when the mic was keyed. Armando Carrillo; Mando repaired an intermittent no start, upon inspection of the starter a cracked

armature brush was found to be at fault.

Today’s automotive technologies range from infrared lasers used in parking assist systems to high speed communication systems. Test equipment has become more sophisticated and practically everything on a vehicle is either actuated via computer output lines or measured in some way for computer inputs. With high tech moni-toring and control systems the diagnosis procedure is more important than ever. As technicians we all develop a systematic approach to problem solving, unfortunately, not all processes are born equal! Is it time to rethink your repair process? Keeping a problem solving process in mind while diagnosing a vehicle will help us be more effi-cient and thorough with the repair process. These steps below should be followed in most cases; 1. Verify the concern; If needed, get more details from the vehicle’s driver. In some cases a con-cern may be intermittent and repeating the condition may be impossible. 2. Visual Inspection; Start with the basics and always eliminate the easiest suspects first. 3. Gather Information; Hook up a scan tool and check for DTC’s, monitor status, mode 6 data, and review module parameters. Check for TSB’s, service campaigns, and gather your service litera-ture. 4. Isolate the failure; Using the resources gathered in step 3, isolate and pinpoint the cause of the failure. 5. Repair; Once the failure has been identified and isolated, repair it. 6. Verify the repair; Perhaps the most critical step in the repair process; verifying the repair proves your diagnosis and repair. Often time’s repairs can be verified by a final test drive and re-viewing scan tool data. Both you and your customer can sleep easier! Making a habit out of good practices will help prevent misdiagnosis and wasted time. Once a solid problem solving approach is adopted by a technician repairing vehicles is a matter of gathering resources and executing a planned diagnosis. Technicians face new problems everyday and finding solutions to these problems requires a proven repair process, which is why reviewing and refining your process will benefit all!

For safety, many repair procedures call for disconnecting the battery. Anytime the battery is disconnected, "Keep Alive" memory to the ECM and other modules is, of course, lost. This means that drivability symptoms may occur on initial restart,

OBD2 monitors will need to be reset before a smog test can be conducted, and all driver settings will be lost. Many of us have used the "memory savers" that use a 9v battery plugged into the cigarette lighter, only to quickly discover that the 9v battery doesn't last long if a door is opened, and often the memory circuits are NOT on the same circuit as the lighter. It has a sealed 12v battery inside, and plugs into the DLC pins 4 and 5 (grounds) and pin 16 (battery voltage). Check any schematic...this connection keeps a 12 volt power supply every-where there is normally a 12v supply "at all times". I would only add one minor detail to using this tool. You need to protect the positive battery cable end from shorting to ground when disconnected from the battery.

Cover Story: Time To Rethink The Repair Process?

Tools & Equipment; EZ Red Computer Memory Saver!

Volume 1 Issue 3

Tech Tips! “By The Techs, For The Techs”

Contributions Needed! • Tech Tips is a new

quarterly publication

• Our goal is to provide up to date news and technical insight as related to vehicle repair.

• We will happily accept articles from you to be presented in this newsletter

• Help us keep the newsletter alive! Your participation is needed!

October 2011

1

Ray Grooms

Ray Grooms

In This Issue Cover Story 1 Time To Rethink The Repair Process Tools & Equip. 1 EZ Red Memory Saver Case Study 2 98 Ford Contour Misfire & Driveability Industry News 3 Laser Ignition! Auto 101 3 HD 9-Pin DLC Tech Tips 4 Clean Brakes Ford Diesel Quick Checks HD EBP Values Scope It! 4 Injectors

Case Study: 98 Ford Contour Misfire & Driveability Vehicle; 1998 Ford Contour 2.0L (Bi-fuel / CNG) Symptoms; Hard misfire Preliminary Inspection; Misfire present at all times. Visual inspection was good, no obvious problems were found. Test Results & Repair; Perform scan test, no DTC’s were present, mode $06 misfire test results were incomplete. A review of the PCM PIDS (powertrain control module parameter ID’s) shows that the misfire monitor isn’t running so we’ll have to diagnose this the old fashioned way. A simple power balance test revealed the misfire was due to a bad ignition coil, when the plug lead was removed the coil fired through a crack in the coil housing to ground. The coil was replaced along with a set of spark plugs and igni-

tion cables for main-tenance. Once a new coil was installed the motor was ran and brought to normal operating temperature and a test drive was performed to allow for adaptive values to be relearned. The engine appears to be running normally but in order to properly verify a repair we need to see what’s going on inside the PCM. Another scan test was done and this is where the real trouble began to show itself. Looking at Fig. 1 we can see that the TFT’s (Total

Fuel Trims = STFT + LTFT) are as high as 28%(should be under 10%)! On top of this the inferred Baro is reading really low at 150.9hz (sea level should result in approx. 161hz.) and the ignition timing seems overly advanced at 27 degrees (a range of 10-20 is

more common at idle). I also noticed my B1S1 O2S (oxygen sensor) appeared to momentarily flat-line at 0 on the EASE scanner (Fig. 2), it also confirmed what the FT’s were telling us, this thing is running lean. From here I decided to scope the O2S and the MAF (Mass Air Flow) sensor, in Fig.3 we can see the O2S signal falls near -.1v! An O2S should never go below 0v, if it does it should be re-placed. The MAF ST test (snap throttle) peaked at 4.02v which is less than the ideal 4.5v. Cleaning the MAF resulted in a slightly increased peak reading of 4.23v and an improved updated Baro

pid of 155hz. Replacing the O2S produced a signal w/ a low of .05v (Fig. 4). Despite the improvements the TFT’s were still high at 20%. My next step was to remove and inspect the air intake system. Once the air intake was removed the problem was found. On the bottom side of the air intake box (between the throttle plate and MAF sensor) I found an open threaded port, it must've been the inlet for the CNG fuel. The CNG system had been disabled and the inlet port left open. So I removed and cleaned the throttle body while I was in there, then plugged the leak with a threaded cap plug. With the scan tool hooked up I started the vehicle and the STFT instantly dropped to -12%, (Fig. 5), this is exactly what we wanted to see! A final test drive allowed for the adaptive values to settle down and the Baro PID to update, the final results in Fig. 6 verify the repair. LTFT at 7.8%, STFT near 0% (TFT’s at 8%), baro at 163hz, and ignition timing at 21degrees. The only question left is why the misfire monitor is not running? Unleaded 1998 model year Fords with 4 cyl. engines use a LDR (Low Data Rate) misfire monitor, this requires wheel profile corrections to be learned, which requires up to 3 separate 60 to 40 mph no braking decels. The wheel profile refers to the crankshaft reluctor wheel, the LDR refers to the number of teeth the reluctor wheel has with low meaning fewer teeth for the CKP sensor to read. The Baro pid also updates with this profile correction process. The Baro did update yet the mis-fire wheel profile correction failed to complete. Ford vehicles will also store a P1000 if any of the monitors are incomplete. This vehicle didn’t set any DTC’s, the conditions to satisfy the profile correction had been met, and the Baro pid updated. My only conclusion for the moment is that Bi-fuel 98 Ford 4 cyl. vehicles were not required to run the misfire monitor and therefore the PCM monitor strategy has been removed. I’ve seen something similar before...Ford trucks over 14,000 lbs. were not required to meet OBD2 requirements and are technically OBD1 compliant, the only functional monitor is the CCM (Comprehensive Component Monitor).

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- Eric Irwin

Fig. 1

Fig. 2

Fig. 3

Fig. 4

These points appeared to flat-line at 0v!

0v line

Notice how the signal falls below 0v?

This EASE screenshot shows the new O2S w/ a minimum value of .05v

The highest this O2S hits here is less than .8v!

Fig. 5

Fig. 6

0 Line

At the recent Conference on Lasers and Electro-Optics (CLEO) held in Baltimore, a team of scientists from Japan’s Institute of Natural Sciences and Romania's National Institute for Laser, Plasma and Radiation physics presented a paper that discussed the possibility of using laser energy to start the combustion process in automobile engines. Ideally, laser ignition results in lower emissions and higher energy efficiency. The idea of lasers being used to ignite an air/fuel mixture is nothing new, early designs go back to the mid 1970’s. The big difference between now and then is the cost of the technology. The Japan based team is boasting affordable production and major improvements in combustion efficiency. Scientists at Liverpool University and engineers at car giants Ford have already developed an ignition system which uses focused beams of laser light to ignite the fuel. Ford hopes to put the laser ignition system into their top of the range vehicles within the next couple of years before making it more widely available (2009).

So what are the key advantages of laser ignition systems? Lasers would potentially offer hotter ignition, which would allow for leaner a/f mixtures allowing for even further reduction of harmful vehicle emissions. Ignition by photon beam would also offer the option of focusing the hot spot in the center of the cylinder rather than generating it at the top. This would allow the "flame front" of the exploding mixture to spread out in all directions and act more efficiently. Multiple focal points can be used as well, offering a much better chance of ignition. Some of the laser can be reflected back from inside the cylinder to provide information for the car on the type of fuel being used and the level of ignition, allowing the car to adjust the quanti-ties of air and fuel automatically to optimize the performance. Speed is also an advantage of laser ignition, laser ignition occurs in nanoseconds compared to spark ignition which occurs in milliseconds. This all boils down to faster, more precise ignition and better con-trol of the combustion forces due to controlled placement of the focal beam. The possi-bility of fuel mixture feedback from within the combustion chamber also opens up the door for potential “mixed fuel” vehicles as the temperature and ignition point within the chamber may potentially be controlled allowing for a broader range of fuel types to be used. So where does the technology stand right now?

The Japan based team has come up with a way of making small, high-power lasers out of ceramics. Their prototype unit is made from two yttrium-aluminum-gallium (YAG) segments, one doped with neodymium, the other with chromium. It is just 9mm in diameter and 11mm long, and by using bursts of pulses less than a nanosecond in du-ration it can ignite a volume of lean fuel-air mix at two points simultaneously. The ce-ramic laser material is thought to be easily tough enough to stand up to conditions in a running car engine. To read more info visit the Y drive Tech Tips folder, a full article is available as well as the Japan Teams research paper!

Auto 101: J1939 9-Pin DLC Pinout & Quick Tests

Industry News: Laser Ignition Systems!

3

- Sal Guerrero

The J1939 Data Link Connector (DLC) is a standardized 9-pin Deutsch connector used in the heavy duty truck industry. It allows a PC or diagnostic tool to communicate with the vehicles onboard diagnostic network. Pins A, B, C, D and E are standard for all 9-pin J1939 DLC’s. The remaining pins are reserved for manufacturer use. The table to the right show the pin orientation and lists the standard pins. Quick Tests at the 9-Pin DLC; 1.)Pin A is battery negative, testing the integrity of your vehicles ground can be done by measuring voltage drop from the battery negative post to Pin A of the 9-pin DLC while using the ground supplied to Pin A as a ground for a light bulb (see Tech Tips Vol. 1 Issue. 1 and Vol. 1 Issue. 2 for more information on voltage drop testing). 2.) Pin B is battery positive and should have system voltage present (B+). Pin A supplies the power for your diagnostic tool. If you’re having problems with scan tool communica-tion Pin A (and B) is the first thing to check. You can also measure voltage drop while loading the ct. with a light bulb at Pin A. 3.) Pins C and D are CAN High and Can Low (in that order). The CAN network uses terminating resistors and a biased voltage, so you should see slightly different voltage levels at the 2 pins. With power disconnected measure the resistance between Pins C and D, there should be 60ohms, if there is 120ohms then one of the terminating resistors is “missing”. If it measures OL then it’s an open ct. A reading of less than 1ohm indicates the data bus wiring is shorted. 4.) Even though Pins F, G, H, and I aren’t standardized we do know that they are there as manufacturer specific network communication protocols. Scoping Pins F and G will allow us to see if the net-work is “talking”. If the pins aren’t used by the manufacturer the cavities will usually be left empty. - Sal Guerrero