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Information on Identifying Non-GM Calibration Usages for LMM Duramax Diesel Engine

Subject:Information on Identifying Non-GM Calibration Usages for LMM Duramax® Diesel Engine

Models:2005-2008 Chevrolet Express, Kodiak, Silverado
2005-2008 GMC Savana, Sierra, TopKick
with 6.6L Duramax® Diesel Engine (VINs D, 2 , 6 -- RPOs LBZ, LLY, LMM)


This bulletin is being revised to add additional model years, a Caution statement regarding likely Powertrain damage and information about documenting non-GM calibration information. Please discard Corporate Bulletin Number 08-06-04-006A (Section 06 -- Engine/Propulsion System).

Caution: Customers should be informed that even after the calibration has been returned to a GM certified configuration, it is likely that engine, transmission, transfer case and/or other driveline components were weakened to the point of premature failure, while subjected to the higher stresses from the non-GM calibration (Power-Up Kit). Engine, transmission, transfer case and/or other driveline components where a non-GM engine calibration has been verified are not covered under the terms of the New Vehicle Warranty.

Power-Up Kit Detection

For 2007-2008 applications, an Engine Control Module (ECM) algorithm was implemented that records the engine calibration part number and Calibration Verification Number (CVN) for the last 10 flash programming events. The ECM only records the engine calibration part number because it contains the parameters for increasing torque and fueling rates.

Some customers may have re-programmed the ECM with a non-GM released calibration. The (Power-Up Kit) powertrain calibration changes fueling and timing parameters and likely contributes to the following vehicle conditions:

    • Poor Performance
    • Black Smoke (This symptom is not valid for the 6.6L (LMM) diesel equipped with the diesel particulate filter (DPF). The DPF will trap black smoke unless the DPF is cracked, melted or has been removed from the exhaust system.)
    • Knocking Noise
    • Engine Damage

If a vehicle comes in for service for a driveability/powertrain concern as a result of a Power-Up Kit installation, the dealership technician now can read the last 10 engine calibration part numbers and CVN history using a Tech 2 ®.

The dealership technician would input each ECM calibration part number into the SPS/TIS2WEB CVN database to confirm the CVN history information. Refer to Tech 2 path table in this bulletin to verify ECM calibration.

2007-2008 LMM Tech 2 Powertrain Output Controls Path Table for NON-GM ECM Calibration

  1. Build the vehicle with the Tech 2.
  2. Select F0: Engine Control Module.
  3. Select F5: Module Identification Information.
  4. Select F1: Programming History.
  5. Turn Ignition On and Engine Off. Press ENTER Key to Continue.

    6. Important: An original production engine operation part number programmed in the ECM from the supplier, which is the last part number shown, would not be in the SPS/TIS2WEB database.

  6. Record the Calibration I.D. Numbers and Verification Numbers from the Tech 2 Programming History Screen.
  7. From SPS/TIS2WEB, record the Calibration Part Number into the CVN Database. Get CVN.
    8. •  If the CVN does not match the CVN database, an unauthorized engine calibration part was flash programmed into the ECM.
    •  If the CVN matches the CVN database, we can assume a Power-Up Kit that flash programs engine calibrations was not used.

2005-2007 LLY and LBZ Instructions for Confirming Calibration Verification Number (CVN)

  1. Go to TIS2WEB
  2. Select "Calibration Information (SPS Info)"
  3. Enter VIN
  4. Select "Get Cal ID"
  5. Select "ECM Engine Control Module"
  6. Select "Next"
  7. Select "Complete History"
  8. Print
  9. Take the printout to the vehicle along with the Tech 2®
  10. Plug in the Tech 2®
  11. Go to diagnostics and build the vehicle
  12. Select "Powertrain"
  13. Select "Engine"
  14. *Select "Engine Control Module"
  15. *Select "Module ID Information" or "I/M Information System" if module ID information selection is not available.
  16. *If "I/M information System" was selected in step 15, it may be necessary to select "Vehicle Information" in order to display the calibration information.
  17. Compare the calibration ID and Calibration Verification Numbers (CVN) to the Calibration Verification Numbers (CVN) on the printout.

* Steps may vary by controller.

Although the part numbers will be the same for each, it's the CVN that will determine if the calibration is GM issued. If ALL of the CVN's are EXACTLY the same, the calibration is GM issued.

If the part numbers match and ANY CVN's DO NOT match the printout, it is likely that a non-GM certified calibration has been installed.

If the CVN information is displayed as "N/A", it will be necessary to contact the TCSC to obtain the CVN information.

If a non-GM calibration is found to be in the ECM (CVN's on the Tech 2 do not match TIS printout) - In order to document the case -- a CLEAR digital picture should be taken of the Tech 2® screen showing the VIN and the CVN's that do not match the TIS2WEB printout. The picture, VIN and reason the vehicle is currently in for service should be emailed to [email protected] for verification. Please copy your GM District Service Manager (DVM) on the e-mail. GM will verify if the CVN's are not GM issued and respond via e-mail within 72 hours.