Identifying Aftermarket Non-GM Calibrations
By Blog Admin on February 1, 2009 7:17 PM | No Comments
For more details, refer to bulletins 08-06-04-033 (Gasoline Engines) and 08-06-04-006A (Diesel Engines).
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 calibrations being used.
When alteration to the GM released engine or transmission control 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 to cancel any remaining warranty coverage to the powertrain and driveline components, whenever the presence of a non-GM / aftermarket 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 are essential to assure reliability, durability and emissions performance over the life of the warranty coverage and beyond. Stresses resulting from calibrations different than those tested and released by GM can damage or weaken components, leading to poor performance and or shortened life.
Additionally; non-GM-issued aftermarket engine control 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.
GM service bulletins 08-06-04-033 and 08-06-04-006 outline procedures to identify the presence of non-GM / aftermarket calibrations. GM recommends performing this check whenever a hard part failure is seen on internal engine or transmission components, or before an engine assembly or transmission assembly is being replaced under warranty. It is also recommended that the engine calibration verification procedure be performed whenever diagnostics indicate that catalytic converter replacement is indicated.
In February 2009, PQC will begin piloting a process to confirm the ECM calibration is GM-issued. Beginning in February, PQC will require a picture of the engine calibration verification screen, as outlined in the bulletin, before authorizing any V8 engine replacement (both Gas and Diesel). (fig. 19)
If a non-GM calibration is detected by the dealership, follow the procedures outlined in the bulletin. Once documentation of the non-GM calibration has been received, and verification has taken place through GM, the remaining powertrain and driveline warranty will be cancelled and noted in VISS, and the dealership will receive the following notification:
Based on information that has been received, please inform the customer that the Powertrain portion of the New Vehicle Warranty is no longer in effect for the engine, transmission, driveline and rear axle on VIN XXXXXXXXXXXXXXXXX, due to the presence of non-GM calibrations and / or equipment. The stresses resulting from the non-GM calibrations and / or equipment were not validated by GM and therefore cannot be warranted on any components that are subject to those stresses. Repairs to powertrain or driveline components that may currently require repair should not be covered under the terms of the new vehicle warranty. The warranty group has been advised of this information and VISS will be updated accordingly.