Identifying Aftermarket Calibrations before Warranty Repairs

[Retired Bob]

http://sandyblogs.com/techlink/?p=4248

 

"When alterations to GM engine or transmission control module calibrations are made by owners, it may subject powertrain and driveline components (the engine, transmission, transfer case, driveshaft and rear axle) to stresses that were not tested by GM. These unknown stresses have the potential to alter reliability, durability and emissions performance. GM is identifying an increasing number of engine, transmission and catalytic converter part failures due to non-GM aftermarket calibrations.

 

As a result, GM has adopted a policy that prevents any unauthorized 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."

<cont in link above>

 

(EDIT) Also read Bulletin 09-06-04-026J

[txchevy4ever]

Makes sense.