P0202 duramax

P0202 duramax DEFAULT

Injector trouble codes

LLY Intermittent SES/MIL Lamp Illuminated, Reduced Engine Power, Fuel Injector Driver Circuit DTCs P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208 and Cylinder Bank Shut Down DTCs P2146 or P2149 (Replace Affected Injector Connector Pigtail Harness)






Models:

2004–2005 Chevrolet Kodiak C4500/C5500 Series, Silverado Models







2004–2005 GMC Sierra Models, TopKick C4500/C5500 Series







with 6.6L Duramax™ Diesel Engine (VIN 2 — RPO LLY)



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This bulletin is being revised to update the Kent Moore tool number used on inspecting the injector connections. Please discard Corporate Bulletin Number 06-06-04-026 (Section 06 — Engine/Propulsion System).
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Condition


Some customers may comment that the Service Engine Soon lamp is illuminated and/or intermittent along with a significant reduction in engine power (limp home mode). Upon investigation, the technician may find one or multiple injector driver circuit diagnostic trouble codes (DTCs) P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208 and bank shut down DTCs P2146 or P2149.

Correction

Important: If the published diagnostics lead to an injector connector on cylinders 2 and 7, the 2 and 7 cylinder injector connectors must be repaired and supported as per bulletin 05-06-04-047B.


If the published diagnostics lead to an injector connector on cylinders 1, 3, 4, 5, 6 or 8, replace the affected injector connector pigtail harness with P/N 88988963 using the following repair procedure.




1.

Complete normal SI diagnosis for the trouble codes set.





2.

Injector circuit or injector coil tests may be normal until the engine reaches operating temperature. Recheck circuit/injector resistance readings with a warm engine.







Important: Dealer technicians are to repair wire chafes at the Fuel Injection Control Module (FICM) as needed. Follow the correct SI wiring repair procedures. Insulate the harness from the aluminum retaining bracket with suitable material (electrical conduit or heater hose) so the harness will not chafe again.







Important: When diagnostics are being completed for Injector Driver Fault codes, the dealer technician may notice the Fuel Injection Control Module (FICM) connector is wet or has a wet residue on it. The FICM connectors do have a type of dielectric grease that may be mistaken for diesel fuel. The FICM should not be replaced if this type of wet residue is found. Clean and dry the connectors as needed. No extra dielectric grease needs to be added to the FICM connectors.





3.

Inspect for wire harness chafes on the Fuel Injection Control Module (FICM) wiring harness retaining bracket. This is an aluminum bracket very close to the FICM connectors. If any part of the taped portion of the harness is touching the FICM wiring harness retaining bracket, then you must look for chaffing on the wiring harness. It must be disconnected from the FICM and bent back towards the engine. Look for any chafes into the tape. If necessary peel the tape from the area and look for any chafes into the wires. Some of these chafes are very small, possibly the size of a pen tip, but could still cause injector circuit concerns.





4.

If diagnosis is inconclusive, inspect the injector connections on all related cylinders. Pin drags and terminal tension can be checked with Kent Moore tool number J 35616-35.





5.

Clear the trouble codes and then wiggle test the related injector connectors to see if the trouble codes can be induced. If the vehicle had only injector circuit codes for P0202 or P0207 (with bank shutdown P2146 or P2149), and the wiggle test induces a P0202 or P0207 to reset, use bulletin number 05-06-04-047B to repair the injector connectors and install the injector harness support kit.





6.

If the trouble codes or customer concern is induced during the wiggle test on any other cylinders (other then P0202/P0207), replace the affected injector connector pigtail with P/N 88988963. This replacement pigtail can be used to repair any cylinder except number 2 and number 7. The 2 and 7 cylinder connectors must be repaired and supported as per bulletin 05-06-04-047B.


Parts Information









Part Number




Description






88988963




Pigtail Harness, Fuel Injector Connector

 

Sours: https://www.plowsite.com/threads/injector-trouble-codes.141141/

P0202 code definition

The P0202 code is a general OBD-II diagnostic trouble code (DTC) associated with the injector circuit.

  • Note: This code may be seen with P0200, P0201, or P0203-P0212. P0202 may also be seen with misfire codes and lean or rich condition codes.

What the P0202 code means

P0202 indicates that the ECM has detected a malfunction for the cylinder 2 injector circuit. The code is set once the ECM detects out-of-range voltage or resistance.

The malfunction causes the ECM to set a Check Engine Light and a failsafe mode. This failsafe mode is to protect the vehicle from further damage. Failsafe is enabled until normal injector operation is found or the fault is repaired.

What causes the P0202 code?

  • Failing or failed cylinder 2 fuel injector
  • Faulty ECM
  • Open or short in the wiring harness for the cylinder 2 injector circuit
  • Poor or broken electrical connection

What are the symptoms of the P0202 code?

  • Check Engine Light present
  • Rich or lean engine conditions causing poor gas mileage
  • Lack of power and poor acceleration
  • Vehicle may stutter or die while running and not restart

How does a mechanic diagnose the P0202 code?

First, a technician will use a scanner to find out what codes are stored in the ECM. These codes will have freeze frame data associated with each code which tells the technician what the vehicle conditions were when the malfunction was detected. All codes will then be cleared and a road test of the vehicle will be done, preferably under conditions similar to when the fault was first detected.

Next, a visual inspection will be performed for the injector circuit looking for any damaged wiring, loose or broken connectors, or components with damage. After the visual inspection, the scan tool will be used to check for injector operation and voltage and resistance.

A digital multimeter will then be used to check for voltage present at the cylinder 2 fuel injector. The technician will then use a noid light installed between the injector and the wiring to test the pulse of the fuel injector.

Lastly, the ECM will be tested if the vehicle passes all other checks.

Common mistakes when diagnosing the P0202 code

Mistakes when repairing and diagnosing the vehicle can be costly and can waste valuable time and money. Care should be taken when performing diagnosis to follow all steps in their entirety and in the correct order. The injector circuit must be fully tested before the fuel injector is replaced to make sure there are no other faults.

How serious is the P0202 code?

P0202 can present serious issues if left unresolved, such as the vehicle dying and not being able to restart. This can be a result of the ECM enabling failsafe mode to protect the vehicle or a failed component, such as a fuel injector. In either circumstance, it is advised to have professional help as soon as possible to get the vehicle back to its normal operation.

What repairs can fix the P0202 code?

A professional will use specialty tools in the diagnostic process of P0202. These are used to ensure accurate diagnosis and to avoid guesswork. A noid light set is used to monitor the pulse width and duration of the fuel injectors a factor that is important in fuel delivery.

Technicians will also need an advanced scan tool that allows live data to be read and graphed will be required as well. Scanners such as these show voltage, ohms, and changes over time that aid in diagnosis.

As vehicles age in years and milage, dirt and contamination can build up in the fuel system causing the fuel system to not operate as designed. Cleaners such as Seafoam can be used to refresh the system and can aide in the repair for P0202.

Need help with a P0202 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

Check Engine Light

P0202

trouble codes

No more waiting rooms! Our mechanics will come to you to diagnose and fix the P0202 code.

Sours: https://www.yourmechanic.com/article/p0202-obd-ii-trouble-code-injector-circuit-malfunction-cylinder-2-by-spencer-clayton
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Chevy Silverado P0202 Check Engine Diagnosis

P0202 is a very common OBD2 trouble code.  It indicates that cylinder 2 in the firing order has a fuel injector malfunction.  It’s generic code, which means that it means the same thing for the Chevy Silverado as it would for any other vehicle.

When the PCM sees voltage at cylinder 2 that is out of the normal operating range, it’ll trigger this code.  P0202 is usually caused by a bad fuel injector or wiring issue.  If the misfire were in cylinder 1, you’d get P0201.

 P0202 is usually caused by a bad fuel injector or wiring issue.

P0202 Chevy Silverado

Chevy Silverado:  P0202 Symptoms

This code is usually accompanied by noticeable symptoms.  Here are the most common ones:

 

  • Misfire– If your Silverado’s fuel injector is not getting the right amount of fuel into cylinder two, it’ll misfire.  A misfire will hurt the acceleration of the vehicle and cause fuel mileage to suffer.
  • Check Engine Light– The check engine light will obviously be on, but you may or may not get a flashing check engine light as well. 

 

P0202 Causes:  Chevy Silverado

The good news when diagnosing P0202 in your Silverado is that you only need to look at the fuel injector in cylinder two, since the computer has pinpointed the location of the problem for you.  

Bad Fuel Injector

Bad fuel injectors are the most common reason that P0202 is thrown by the PCM.  You still want to take a look at the wiring harness.  You’ll also want to test the injector.  There’s a YouTube video directly above that shows how to do that.  A new fuel injector is relatively affordable.

Fuel injectors can make your Silverado’s PCM throw P0202 if they are plugged, dirty, or defective.

 

Wiring Issue

When diagnosing P0202, taking a look at the wiring around the injector is a great place to start.  You want to make sure that it doesn’t look visibly damaged.

Make sure that the voltage at the injector matches the injectors that aren’t getting the code.  If they aren’t that’s a good indication that something is wrong with the wiring harness.

 

Bad PCM

This is the last place that you’d want to look, but a bad PCM can be the reason why your Silverado is getting P0202. 

 

Conclusion:  P0202 Chevy Silverado

It’s usually not too hard to track down P0202, thanks to the fact that it is specific to the first cylinder.  If there is anything you would like to add that could help the next person with their Silverado, please leave a comment.  Good luck!

 

Categories Chevy SilveradoSours: https://www.700r4transmissionhq.com/p0202-chevy-silverado/
Common Problem with LLY Duramax - *FIXED*

The Duramax Dilemma: Injector Circuit Diagnostics

Click Here to Read More

The owner of this GM Duramax was headed to Montana on vacation with his family and camper trailer in tow. After stopping for lunch, the owner was dismayed to find that his Duramax immediately went into “limp mode” as the engine started. A shop in a nearby town recommended replacing four fuel injectors. A red flag went up in the owner’s mind because the GMC had been bought from a private owner who claimed that all eight injectors had been replaced prior to the sale. The current owner called a mutual friend of ours who works as a heavy-duty mechanic for a local construction company. This friend then called me to see if I could diagnose the problem causing the limp-mode operation. I consented. This set me on my path of wandering through a weed patch of expensive repairs and less-than-precise service information.

Modern technology is overwhelming the modern automotive technician, and I’m no exception. That being said, I’ll warn you in advance that this story is going to be as much about the current state of our diagnostic trade as it is about General Motors Duramax diagnostics. To begin my “weed patch” story, you should know the local shops in my area were overwhelmed this summer with tourists and summertime residents. Most shops were booked out two or three weeks, which is why I was called to diagnose a 2003 GMC Sierra 3500 equipped with the Duramax diesel.

Not that I’m a diesel specialist, but I did teach diesel maintenance during my final year as an auto mechanics instructor during the 1970s. One of the basics I taught regarding mechanical diesel fuel injection was the T.A.M.P. principle (Timing, Atomization, Metering and Pressure). These are the four variables required to be in sync for a direct-injection fuel system to properly perform on a compression ignition engine. Eliminate, or alter, any of those four functions, and the engine will either fail to start or not perform as designed. While these four principles are as valid today as they were 40 years ago, the technology driving each has changed dramatically.

A cast-aluminum bracket (lower center) causes harness chaffing problems. The FICM is located at the center of the photo.

DTCs U1800 and P2149

Since the owner had also reported a fuel gauge malfunction, I successfully completed a gauge sweep and checked for powertrain “P” codes, body control “B” codes and communication “U-codes.” I found codes U1800 and P2149. An underhood inspection revealed that the previous shop that had worked on the car disconnected several wiring harnesses and had broken open the plastic loom cover to the Fuel Injection Control Module (FICM), which is bolted to the passenger-side valve cover.

General Motors details a chafing problem in the FICM wiring harness (TSB #09-06-04-034) as it passes behind the alternator mounted on the front passenger side of the engine. This problem is caused by a poorly designed metal mount for the harness and requires a thorough inspection of the FICM harness where it passes behind the alternator. The previous shop had obviously been aware of this TSB and had taken the harness apart for inspection. 

In brief, the U1800DTC is related to communication issues with the FICM. Due to several harnesses having been disconnected from the engine, I ignored the U1800 DTC for the moment. That said, the enabling criteria for P2149 indicated that P2149 would not run in the presence of U1800. That was a little confusing, but P2149 proved to be the more problematic of the two codes.

DTC P2149

The FICM separates the high-voltage injector circuits into two groups: cylinders #2, #3, #5 and #8 and cylinders #1, #4, #6 and #7. The firing order is 1-2-7-8-4-5-6-3 with the odd-numbered cylinders located on the passenger side of the engine and the even-numbered cylinders located on the driver’s side. DTC P2149 sets when the FICM detects a fault in the high-voltage circuits of fuel injectors #2, #3, #5 and #8. According to the circuit description, DTCs P0202, P0203, P0205and P0208 should also set. DTC P2146 will set if similar high-voltage circuit problems are detected in fuel injectors #1, #4, #6 and #7. Keep in mind that a P0200 references an electrical circuit problem, while a P0300 references a minor change in crankshaft speed due to a mechanical fuel injection or cylinder compression issue.

The FICM, intake ducting, air filter/MAF assembly, and many other items must be removed to gain access to the passenger-side rocker arm cover.

 

The P2149 Dilemma

Since the FICM disables the electrical circuits of all four injectors in each group, testing the injector circuits with a lab scope is a waste of time. According to service information, the correct diagnostic procedure is to use a professional volt/ohmmeter to measure the resistance of each fuel injector circuit. The specified resistance at room temperature is between 0.3 to 0.4 ohms.

Before measuring the resistance of any circuit, remove the negative cable on each battery. Since .3 ohms is a very small resistance, the ohmmeter leads must be clean and the meter must be perfectly “zeroed” by crossing the leads and pushing the “relative” button. If the ohmmeter doesn’t have the “rel” feature, jot down the leads’ resistance and subtract that from the total reading when measuring circuit resistance. Last, connect the negative ohmmeter lead to a clean engine ground. Since we’re measuring through the connector side of the harness, I used a needle-point probe to avoid deforming the female connector pins.

The injector circuit resistance is measured between the B+ source in the FICM C1 and C2 connectors and their injector “command” circuits. The command circuit pulls the injector to ground through the FICM, while the control circuit reports injector activity to the PCM. With the FICM connectors removed, the control circuit should measure infinity. In the case of our 2003 Sierra, each injector measured a perfect 0.3 ohms, which became this month’s Diagnostic Dilemma.

Dollars and Cents

It was at this point that I understood why the previous shop had recommended replacing all four injectors. Sure, it’s easy to talk about pinpoint diagnostics, but with the fourth pin-out on the FICM C1 and C2 connectors yielding the same results, I really didn’t have any place to go with the diagnostics except to replace the FICM as recommended by service information.

The wiring on the injectors is very simple: One wire powers the injector while the FICM fires the injector by grounding the other.

The recommended resale from my supplier on these remanufactured injectors is about $1,600 for the set of four. Replacing all four injectors required removing both right- and left-bank rocker arm covers and the overlay of wiring harnesses and ducting covering of each. Quoting from one source, the labor time for removing and replacing both covers is about 9.2 hours for “severe service” cases. While the math varies according to parts sourcing and local labor rates, my estimated price came out at about $3,000 for replacing all four injectors. Of course, the owner had assumed that all eight injectors had been recently replaced, and I had no way of verifying that claim other than the engine appeared very clean for 138,000 miles of use. If we replaced all eight injectors, my estimated price would approach $5,000. Due to warranty issues and the labor times involved, it’s understandable why some shops would replace at least four, if not all eight, injectors. Fair or not, these are the economic realities of dealing with modern technology.

Into the Weed Patch

Since all eight injectors measured within OE specification, the diagnostic flowchart indicated that the FICM module should be replaced. After 30 years of reading factory flowcharts, a technician develops an intuitive sense when a diagnosis is headed into the weed patch. My aftermarket case study information indicated that the odds of finding a bad fuel injector or a bad FICM module causing the P1249 DTC were about even. Here again, I had no place to go with the diagnosis except to follow service information. The dealership price for a reman FICM edged into four digits. My aftermarket supplier supplied a similar reman for half that much. I hedged my bet by choosing the less expensive aftermarket FICM to limit my losses if the diagnosis proved wrong, which of course, it did.

Uncharacteristically, I kept the GMC Sierra for over a month, primarily because we didn’t have time or space to replace the fuel injectors and also because I didn’t want to replace thousands of dollars in unnecessary parts for a young guy with a young family. With all other options exhausted, we finally decided to replace all four fuel injectors. Not one to give up, I decided that I would once again go through the diagnostic and pin-out procedure. I cleared the P1249 DTC, turned on the switch and cranked the engine a few turns.

Low and behold, the P1249 had returned as it had numerous times before. But the only code displayed was a P0205, which indicated a circuit fault on #5 fuel injector. Working quickly before the cylinder heads warmed up, we removed the FICM connectors and repeated the pin test. Sure enough, #5 fuel injector measured well under specification at 0.2 ohms while the remaining seven injectors measured their normal 0.3 ohms. Evidently, the extra-cold morning had tipped the scales in our favor by revealing a shorted injector circuit on #5 fuel injector. With the new injector and the original FICM in place, the engine ran perfectly. End of story? Not so fast!

As seen in this photo, the FICM harness has been repaired and is shielded from further chafing by a length of large-diameter split loom.

Modern Technology and Training Issues

When I worked at a dealership in the 1970s, General Motors maintained an excellent training center for our mountain-area states. I received a great deal of my early technical training at that facility. However, the last time I saw it, its parking lot was overcome by weeds — an image that perfectly symbolizes the state of modern technical training. As I understand it, the majority of dealership training is now delivered via the Internet or DVD. The fact is, hands-on training provided by experienced instructors has, in many cases, become a thing of the past.

Currently, most of the training I receive is through trade shows and individual classes offered by parts manufacturers. Sadly, the attendance record for individual classes is dismal. A few years ago, I made a 275-mile round-trip journey to attend an eight-hour class on gasoline direct fuel injection that was offered by a major supplier. Including fuel and an overnight stay, my overall cost was about $500. The attendance at that class was fewer than 20 technicians. While the training was excellent, it was apparent that independent shops scattered throughout the mountain states had failed to support the class.

I contend that the diagnostic weed patch I detailed at the beginning of this story can be directly correlated to the physical weed patch surrounding our former General Motors training center. Times have changed, and training isn’t what it used to be.

I discovered in my experience with my Duramax Dilemma that having access to OE service information often isn’t enough to arrive at an accurate service recommendation. What I really needed was the advice of an experienced instructor to warn me of the pitfalls associated with diagnosing the infamous P2149 and P2146 DTCs. I also needed a far better understanding of system operating principles than those that were supplied by the service information. While blind luck ended up helping me successfully conclude this month’s Diagnostic Dilemma, I can only hope to be so lucky in the future.

Sours: https://www.underhoodservice.com/duramax-dilemma-injector-circuit-diagnostics/

Duramax p0202

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  1. 10-25-2002, 20:58#1
    Join Date
    Nov 2001
    Location
    Salt Lake City, UT USA
    Posts
    54

    Question

    A couple nights ago truck goes into Limp Mode on Highway. THought it was same problem with tranny had before.

    Took to dealer and this is what they came up with.

    "51879 Checked for the check engine light coming on. Checked the PCM for codes and found that it had a code P0202 Injector Supply Voltage Circuit. Done the diagnostic for the code could not duplicate the code resetting"

    So basically the truck broke down, had to be towed in, reset itself overnight and now they say nothings wrong.

    ANy ideas what this is and should I be worried?

    THanx
    Jim
    2001 Chevy 3500 Ext Cab (white), Duramax Diesel, Allison Tranny, K&N Breather.

  2. 10-29-2002, 11:52#2
    Join Date
    Nov 2001
    Location
    Salt Lake City, UT USA
    Posts
    54

    Post

    Update,
    After picking up the truck on Friday from dealer who said they could not duplicate the error it broke down again yesterday. Seems like the same problem and truck is back at dealer.

    Has anybody else had this code problem? And if so what was the resolution to the problem.

    THank you
    Jim
    2001 Chevy 3500 Ext Cab (white), Duramax Diesel, Allison Tranny, K&N Breather.

  3. 10-29-2002, 15:22#3
    Join Date
    Mar 2002
    Location
    Albuquerque, New Mexico
    Posts
    13

    Talking

    Jim,
    Have the dealership check their diagnostic procedure. I have copied it here as well, but some of the setups have been eliminated. The general idea is listed below.
    Tom


    DTC P0201-P0208
    Circuit Description
    The fuel injection control module (FICM) supplies high voltage to each fuel injector on the injector supply voltage circuits. The FICM enables each fuel injector by grounding the command circuit between the FICM and the fuel injector. The FICM monitors the status of the injector supply voltage circuits and the fuel injector command circuits. When a fuel injector circuit condition is detected by the FICM, all of the fuel injectors on the affected injector supply voltage circuit will be disabled. If a circuit condition is detected on a fuel injector circuit for cylinders 1, 4, 6, or 7, DTCs P0201, P0204, P0206, P0207 will set, along with DTC P1261. If a circuit condition is detected on a fuel injector circuit for cylinders 2, 3, 5, or 8, DTCs P0202, P0203, P0205, P0208 will set, along with DTC P1262.

    Conditions for Running the DTC
    DTCs U1800, and U2104 are not set.
    The engine is running.
    The charging system voltage is between 6-18 volts.
    Conditions for Setting the DTC
    The FICM detects an incorrect current on a fuel injector circuit.
    The condition exists for less than 1 second.
    Action Taken When the DTC Sets
    The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
    The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records.
    The control module disables the set of fuel injectors that have a concern.
    Conditions for Clearing the MIL/DTC
    The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
    A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
    A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
    Clear the MIL and the DTC with a scan tool.
    Test Description
    The numbers below refer to the step numbers on the diagnostic table.

    This step verifies that the condition is not intermittent.

    This step determines which set of fuel injectors the circuit condition is affecting. If DTC P1261 is set, then a condition exists on cylinders 1, 4, 6, or 7. If DTC P1262 is set, then a condition exists on cylinders 2, 3, 5, or 8.

    This step tests if a ground is constantly being applied to the fuel injectors.

    This step isolates which circuit is causing the condition. If the test lamp turns OFF when a multi-way connector is disconnected, test the affected circuits for a short to ground.

    This step tests for an open circuit. If the DMM displays OL on all of the fuel injector circuits, the ignition voltage circuit is open.

    This step tests for an open circuit. If the DMM displays OL on one of the fuel injector circuits, the fuel injector command circuit is open.

    This step tests for excessive resistance in a fuel injector circuit.

    This step is testing for a short between the ignition feed circuit, and the fuel injector command circuit. If the resistance of the circuits is less than 0.3 ohms, test for a short between the circuits. If a short cannot be found, the fuel injector may be the cause of the condition. The normal fuel injector resistance is between 0.3-0.4 ohms.

    This step tests for a short to voltage on a fuel injector circuit. If the DMM displays battery voltage, a short to voltage is the cause of the condition.

    This step isolates which circuit is causing the condition. If the DMM display changes to 0 volts when a multi-way connector is disconnected, test the affected circuits for a short to voltage.

    This step tests if a ground is constantly being applied to the fuel injectors.

    This step isolates which circuit is causing the condition. If the DMM displays OL when a multi-way connector is disconnected, test the affected circuits for a short to ground.

    This step tests for an open circuit. If the DMM displays OL on all of the fuel injector circuits, the ignition voltage circuit is open.

    This step tests for an open circuit. If the DMM displays OL on one of the fuel injector circuits, the fuel injector command circuit is open.

    This step tests for excessive resistance in a fuel injector circuit.

    This step is testing for a short between the ignition feed circuit, and the fuel injector command circuit. If the resistance of the circuits is less than 0.3 ohms, test for a short between the circuits. If a short cannot be found, the fuel injector may be the cause of the condition. The normal fuel injector resistance is between 0.3-0.4 ohms.

    This step tests for a short to voltage on a fuel injector circuit. If the DMM displays battery voltage, a short to voltage is the cause of the condition.

    This step isolates which circuit is causing the condition. If the DMM display changes to 0 volts when a multi-way connector is disconnected, test the affected circuits for a short to voltage.

    Step
    Action
    Values
    Yes
    No

    Schematic Reference: Engine Controls Schematics

    Connector End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls Connector End Views

    1
    Did you perform the Diagnostic System Check-Engine Controls?
    --
    Go to Step 2
    Go to Diagnostic System Check - Engine Controls

    2
    Observe the DTC information with a scan tool.

    Are DTCs P0201, P0204, P0206, P0207, or P0202, P0203, P0205, P0208 set?
    --
    Go to Step 4
    Go to Step 3

    3
    Observe the Freeze Frame/Failure Records for this DTC.
    Turn OFF the ignition for 30 seconds.
    Start the engine.
    Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.
    Did the DTC fail this ignition?
    --
    Go to Step 4
    Go to Intermittent Conditions

    4
    Is DTC P1261 also set?
    --
    Go to Step 13
    Go to Step 5

    5

    Important
    Refer to Engine Controls Component Views for fuel injector locations. Failure to identify the correct cylinder will result in misdiagnosis.


    Turn OFF the ignition.
    Disconnect the FICM.
    Measure the resistance between the injector supply voltage circuit for cylinders 2, 3, 5 and 8, and the ground with a DMM.
    Does the DMM display OL?
    --
    Go to Step 7
    Go to Step 6

    6
    Disconnect each multi-way harness connector of the fuel injectors one at a time, while monitoring the DMM.

    Does the DMM display OL when any of the fuel injector harness connectors are disconnected?
    --
    Go to Step 21
    Go to Step 34

    7

    Important
    The DMM and test leads must be calibrated to 0 ohms in order to prevent misdiagnosis. Use the J 39200 DMM to perform this test. Refer to the DMM User Manual for calibration procedure.


    Measure the resistance between the ignition voltage circuit and the injector command circuits for cylinders 2, 3, 5 and 8 with a DMM.

    Does the DMM display OL for all of the circuits?
    --
    Go to Step 35
    Go to Step 8

    8
    Does the DMM display OL for any of the circuits?
    --
    Go to Step 23
    Go to Step 9

    9
    Does the DMM display a resistance above the specified value for any fuel injector circuit?
    0.8 ohms
    Go to Step 26
    Go to Step 10

    10
    Does the DMM display a resistance below the specified value for any fuel injector circuit?
    0.3 ohms
    Go to Step 28
    Go to Step 11

    11
    Turn ON the ignition, with the engine OFF.
    Probe the ignition voltage circuit for cylinders 2, 3, 5 and 8 with a DMM connected to ground.
    Does the DMM display battery voltage?
    --
    Go to Step 12
    Go to Step 29

    12
    Disconnect each multi-way harness connector of the fuel injectors one at a time, while monitoring the DMM.

    Does the DMM display the specified voltage when any of the fuel injector harness connectors are disconnected?
    0 V
    Go to Step 32
    Go to Step 31

    13

    Important
    Refer to Engine Controls Component Views for fuel injector locations. Failure to identify the correct cylinder will result in misdiagnosis.


    Turn OFF the ignition.
    Disconnect the FICM.
    Measure the resistance between the injector supply voltage circuit for cylinders 1, 4, 6 and 7, and the ground with a DMM.
    Does the DMM display OL?
    --
    Go to Step 15
    Go to Step 14

    14
    Disconnect each multi-way harness connector of the fuel injectors one at a time, while monitoring the DMM.

    Does the DMM indicate OL when any of the fuel injector harness connectors are disconnected?
    --
    Go to Step 21
    Go to Step 34

    15

    Important
    The DMM and test leads must be calibrated to 0 ohms in order to prevent misdiagnosis. Refer to the DMM User Manual for calibration procedure.


    Measure the resistance between the injector supply voltage circuit and the injector command circuits for cylinders 1, 4, 6 and 7 with a DMM.

    Does the DMM display OL for all of the circuits?
    --
    Go to Step 35
    Go to Step 16

    16
    Does the DMM display OL for any of the circuits?
    --
    Go to Step 23
    Go to Step 17

    17
    Does the DMM display a resistance above the specified value for any fuel injector circuit?
    0.8 ohms
    Go to Step 26
    Go to Step 18

    18
    Does the DMM display a resistance below the specified value for any fuel injector circuit?
    0.3 ohms
    Go to Step 28
    Go to Step 19

    19
    Turn ON the ignition, with the engine OFF.
    Probe the injector supply voltage circuit for cylinders 1, 4, 6 and 7 with a DMM connected to ground.
    Does the DMM display battery voltage?
    --
    Go to Step 20
    Go to Step 29

    20
    Disconnect each multi-way harness connector of the fuel injectors one at a time, while monitoring the DMM.

    Does the DMM display the specified voltage when any of the fuel injector harness connectors are disconnected?
    0 V
    Go to Step 32
    Go to Step 31

    21
    Measure the resistance from the fuel injector command circuit to ground between the FICM and the multi-way connector for the cylinder that caused the DMM to display OL.

    Does the DMM display continuity?
    --
    Go to Step 33
    Go to Step 22

    22
    Test both of the fuel injector circuits, of the isolated cylinder, between the fuel injector and the multi-way connector for a short to ground. Refer to Testing for Short to Ground and Wiring Repairs in Wiring Systems.

    Did you find and correct the condition?
    --
    Go to Step 38
    Go to Step 30

    23
    Disconnect the multi-way connector of the fuel injector that displayed OL.
    Test the command circuit of the fuel injector, between the FICM and the multi-way connector, for the following:
    An open circuit
    A poor connection
    Refer to Connector Repairs or Wiring Repairs in Wiring Systems.
    Did you find and correct the condition?
    --
    Go to Step 38
    Go to Step 24

    24
    Test the ignition voltage circuit of the fuel injector, between the multi-way connector and the splice, for the following:
    An open circuit
    A poor connection
    Refer to Connector Repairs or Wiring Repairs in Wiring Systems.
    Did you find and correct the condition?
    --
    Go to Step 38
    Go to Step 25

    25
    Test both of the fuel injector circuits between the fuel injector and the multi-way connector for an open. Refer to Testing for Continuity and Wiring Repairs in Wiring Systems.

    Did you find and correct the condition?
    --
    Go to Step 38
    Go to Step 30

    26
    Disconnect the multi-way connector for the circuit with high resistance.
    Test for the following conditions:
    Excessive resistance in the fuel injector circuits between the FICM and the multi-way connector
    Poor connections at the multi-way connector of the fuel injector
    Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Wiring Systems.
    Did you find and correct the condition?
    --
    Go to Step 38
    Go to Step 27

    27
    Test both of the fuel injector circuits between the fuel injector and the multi-way connector for high resistance. Refer to Testing for Continuity and Wiring Repairs in Wiring Systems.

    Did you find and correct the condition?
    --
    Go to Step 38
    Go to Step 30

    28
    Test for a short between the injector supply voltage ignition circuit and the fuel injector command circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

    Did you find and correct the condition?
    --
    Go to Step 38
    Go to Step 36

    29
    Inspect for poor connections at the harness connector of the FICM. Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Wiring Systems.

    Did you find and correct the condition?
    --
    Go to Step 38
    Go to Step 37

    30
    Inspect for poor connections at the harness connector of the fuel injector. Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Wiring Systems.

    Did you find and correct the condition?
    --
    Go to Step 38
    Go to Step 36

    31
    Repair the short to voltage in the injector supply voltage circuit. Refer to Wiring Repairs in Wiring Systems.

    Did you complete the repair?
    --
    Go to Step 38
    --

    32
    Repair the short to voltage in the fuel injector command circuit that turned OFF the test lamp. Refer to Wiring Repairs in Wiring Systems.

    Did you complete the repair?
    --
    Go to Step 38
    --

    33
    Repair the short to ground in the fuel injector command circuit. Refer to Wiring Repairs in Wiring Systems.

    Did you complete the repair?
    --
    Go to Step 38
    --

    34
    Repair the short to ground in the injector supply voltage circuit. Refer to Wiring Repairs in Wiring Systems.

    Did you complete the repair?
    --
    Go to Step 38
    --

    35
    Repair the open in the injector supply voltage circuit. Refer to Wiring Repairs in Wiring Systems.

    Did you complete the repair?
    --
    Go to Step 38
    --

    36

    Important
    Refer to Engine Controls Component Views for fuel injector locations.


    Replace the appropriate fuel injector. Refer to Fuel Injector Replacement .

    Did you complete the replacement?
    --
    Go to Step 38
    --

    37
    Replace the FICM. Refer to Fuel Injection Control Module Replacement .

    Did you complete the replacement?
    --
    Go to Step 38
    --

    38
    Clear the DTCs with a scan tool.
    Turn OFF the ignition for 30 seconds.
    Start the engine.
    Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.
    Did the DTC fail this ignition?
    --
    Go to Step 2
    Go to Step 39

    39
    Observe the Capture Info with a scan tool.

    Are there any DTCs that have not been diagnosed?
    --
    Go to Diagnostic Trouble Code (DTC) List
    System OK

    2002 2500HD 4x4 CC 8.1/allison Indigo Blue/Tan Luvern Steps

  4. 10-29-2002, 19:32#4
    Join Date
    Jul 2002
    Location
    illinois
    Posts
    517

    Cool

    you Da,man,Tom......I am betting they didn't do the scan properly...

    The guy at Gm corporate told me "We encourage owner participation in vehicle diognostics and repairs."

    but the dealers don't seem to like it..
    2002 GMC...Dmax in Black of course..X-cab 4 by 4..<br />Goodmark Cowl Inducton Hood<br />Lund Screen front<br />Stainless nerf Bars<br />aux tank<br />Jardine 4\" Exhaust<br />and some more stuff

  5. 10-29-2002, 21:29#5
    Join Date
    Jun 2002
    Location
    Birmingham, AL
    Posts
    561

    Post

    Heck, I'd just call JK and ask him what's up? Probably just a week connection. The heat makes it sag enough, or swell, making the ground.


    Just a guess... .02$ worth


    Burner
    2003 GMC SLT CC 4x4 SB-Cooper Tires-Speed Liner-Activator II-Full length ICI SS step bars B&W Goose & more to come
    -- Member #7527
    E-Mail --&gt;Twomuchplay(at)AOL(dot)com

  6. 10-30-2002, 11:42#6
    Join Date
    Nov 2001
    Location
    Salt Lake City, UT USA
    Posts
    54

    Post

    Wednesday update

    Dealer confirms it is a voltage problem with #1 cylinder. Either bad injector or bad wiring. They are diagnosing now...

    Would this be covered under engine warranty? I hope so....

    Jim
    2001 Chevy 3500 Ext Cab (white), Duramax Diesel, Allison Tranny, K&N Breather.

  7. 10-30-2002, 21:18#7
    Join Date
    Nov 2001
    Location
    Salt Lake City, UT USA
    Posts
    54

    Post

    Dealer called today and said the fuel rail was loose and causing a short. Also said they messed up a seal when retightening and should be fixed tomorrow.

    Does this sound plausible?

    THanx
    2001 Chevy 3500 Ext Cab (white), Duramax Diesel, Allison Tranny, K&N Breather.

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