Section 1

1. Engine, Transmission, Transfer Case, Rear Axle Components and Catalytic Converter Failures Due to Non-GM Engine and/or Transmission Control Module Calibrations Being Installed - Including GM Calibration Verification Requires and Recommends Notices

Notice
- Be advised that GM REQUIRES retrieving the Calibration Information and performing the Calibration Verification Procedure as outlined in this Bulletin, whenever diagnostics determine a hard part failure may have occurred on internal engine parts and BEFORE disassembly, repair or replacement of an engine assembly under warranty.

- Be advised that GM strongly RECOMMENDS retrieving the Calibration Information and performing the Calibration Verification Procedure as outlined in this Bulletin, whenever diagnostics determine a hard part failure may have occurred on transmission, transfer case or rear axle components and BEFORE disassembly, repair or replacement of a transmission, transfer case or rear axle assembly under warranty. It is also RECOMMENDED that the engine control module Calibration Verification Procedure be performed whenever diagnostics determine that catalytic converter replacement is necessary.

- While it is not a REQUIREMENT to verify transmission control module calibrations on gasoline engine applications, like it is with engine control module calibrations, they can still be verified in the same manner if it is necessary for any reason.

General Motors is identifying an increasing number of engine, transmission and catalytic converter part failures that are the result of non-GM (aftermarket) engine and transmission control module calibrations being installed.

When alteration to the GM-released engine or transmission control module calibrations occurs, it subjects powertrain and driveline components (engine, transmission, transfer case, driveshaft and rear axle) to stresses that were not tested by General Motors. It is because of these unknown stresses, and the potential to alter reliability, durability and emissions performance, that GM has adopted a policy that prevents any UNAUTHORIZED Service Agent warranty Transaction submissions to any remaining warranty coverage, to the powertrain and driveline components whenever the presence of a non-GM calibration is confirmed - even if the non-GM control module calibration is subsequently removed.

Warranty coverage is based on the equipment and calibrations that were released on the vehicle at time of sale, or subsequently updated by GM. That's because GM testing and validation matches the calibration to a host of criteria that is essential to assure reliability, durability and emissions performance over the life of the warranty coverage and beyond. Stresses resulting from calibrations that are different from those tested and released by GM can damage and/or weaken components, leading to poor performance and/or shortened life.

Additionally, non-GM issued engine control module modifications often do not meet the same emissions performance standards as GM issued calibrations. Depending on state statutes, individuals who install engine control module calibrations that put the vehicle outside the parameters of emissions certification standards may be subject to fines and/or penalties.

This bulletin outlines the Calibration Retrieval and Calibration Verification Procedures for ALL Service Agents including Service Agents NOT Required to Call PQC for Powertrain/Drivetrain Assembly Replacement Authorization and Service Agents Required to Call PQC for Powertrain/Drivetrain Assembly Replacement Authorization, using the Tech 2(R) or GDS 2 to identify the presence of non-GM control module calibrations.

If a non-GM calibration is found and verification has taken place through GM, the remaining powertrain and driveline warranty may be blocked and notated in Global Warranty Management (GWM) and the dealership will be notified. This block prevents any UNAUTHORIZED warranty claim submission.