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Identifying Aftermarket Engine and Transmission Calibrations Gas Powered Engines Only and Automatic Transmissions

Subject:Identifying Aftermarket Engine and Transmission Calibrations 2.0L, 2.2L, 2.4L, 2.8L, 2.9L, 3.0L, 3.1L, 3.2L, 3.4L, 3.5L, 3.6L, 3.8L, 3.9L, 4.2L, 4.3L, 4.4L, 4.6L, 4.8L, 5.0L, 5.3L, 5.7L, 6.0L, 6.2L, 7.0L, 7.4L, 8.1L Gas Powered Engines Only and 6T40/45 (MH8), 6T70/75 (MH2, MH4, MH6, MY9), 6L50 (MYB) 6L80 (MYC) or 6L90 (MYD) Automatic Transmission

Models:2006-2009 GM Passenger Cars and Light Duty Trucks
2006-2009 HUMMER H2, H3
EXCLUDING Pontiac Vibe, Wave, Chevrolet Aveo, All Saturn and Saab Models


This bulletin is being revised to remove the Pontiac G8 from the list of excluded vehicles. Please discard Corporate Bulletin Number 08-06-04-033A (Section 06 -- Engine/Propulsion System).

Important: This bulletin applies to Gas Powered Engines ONLY. For Diesel Powered Engines, refer to Service Bulletin #08-06-04-006A.

If a suspicious hard part failure is observed in the engine, transmission, transfer case or driveline, perform the calibration verification described to determine if a non-GM issued engine calibration is installed. Non-GM issued engine calibrations subject driveline components to stresses different than the calibrations which these components were validated to. Repairs to 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.

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" or "TCM Transmission 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" or "PCM" or "TCM"
  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 or TCM (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 CVNs 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] and [email protected] for verification. Please copy your GM District Service Manager (DVM) on the e-mail. GM will verify if the CVNs are not GM issued and respond via e-mail within 72 hours.