GM reporting Duramax Diesel powertrain issues caused by aftermarket software; non-GM software voids powertrain warranties

19 August 2012

General Motors has released Technical Service Bulletin (TSB) 08-06-04-006J, which provides updated information to dealership service departments on identifying non-GM engine control module (ECM) calibrations. The bulletin also extends the procedures to cover many Duramax-equipped vehicles built for model year 2013.

The bulletin outlines software identification and power-up hardware detection procedures, and recommends that such procedures be carried out whenever a “hard part failure” is observed on internal engine, transmission, transfer case, rear axle assembly, or exhaust after-treatment system that is under warranty.

GM reports an “increasing number” of engine, transmission, diesel oxidation catalyst, and exhaust particulate filter failures in vehicles that have been retrofitted with non-GM engine and/or transmission software calibrations.

A number of companies offer kits which modify software calibrations in the powertrains of production vehicles. Although such kits are normally sold with required disclaimers indicating that the modifications are for off-highway use only, the market for such kits is generally assumed to be owners of vehicles which are driven on public highways.