C 2500 3/4 Ton Pickup 2WD V8-379 6.2L DSL VIN J FI (1984)
Engine Control Module: Technical Service Bulletins
Engine Controls - Aftermarket Accessory Usage
Bulletin No.: 04-06-04-054B
Date: November 18, 2010
Subject: Info - Non-GM Parts and Accessories (Aftermarket)
2011 and Prior GM Passenger Cars and Trucks
This bulletin is being revised to add model years and update to the new U.S. Fixed Operation Manager (FOM) and Canada Warranty Manager (WM)
names. Please discard Corporate Bulletin Number 04-06-04-054A (Section 06 - Engine/Propulsion System).
The recent rise and expansion of companies selling non-GM parts and accessories has made it necessary to issue this reminder to dealers regarding GM's
policy on the use and installation of these aftermarket components.
When a dealer is performing a repair under the New Vehicle Limited Warranty, they are required to use only genuine GM or GM-approved parts and
accessories. This applies to all warranty repairs, special policy repairs or any repairs paid for by GM. Parts and accessories advertised as being "the
same" as parts manufactured by GM, but not sold through GM, do not qualify for use in warranty repairs, special policy repairs or any repairs paid for by
During a warranty repair, if a GM original equipment part is not available through GM Customer Care and Aftersales (GM CC&A), ACDelco(R)
distributors, other GM dealers or approved sources, the dealer is to obtain comparable, non-GM parts and clearly indicate, in detail, on the repair order
the circumstances surrounding why non-GM parts were used. The dealer must give customers written notice, prior to the sale or service, that such parts
or accessories are not marketed or warranted by General Motors.
It should also be noted that dealers modifying new vehicles and installing equipment, parts and accessories obtained from sources not authorized by GM
are responsible for complying with the National Traffic and Motor Vehicle Safety Act. Certain non-approved parts or assemblies, installed by the dealer
or its agent not authorized by GM, may result in a change to the vehicle's design characteristics and may affect the vehicle's ability to conform to federal
law. Dealers must fully understand that non-GM approved parts may not have been validated, tested or certified for use. This puts the dealer at risk for
potential liability in the event of a part or vehicle failure. If a GM part failure occurs as the result of the installation or use of a non-GM approved part,
the warranty will not be honored.
A good example of non-authorized modification of vehicles is the result of an ever increasing supply of aftermarket devices available to the customer,
which claim to increase the horsepower and torque of the Duramax(TM) Diesel Engines. These include the addition of, but are not limited to one or
more of the following modifications:
Nitrous oxide injection
Additional modules (black boxes) that connect to the vehicle wiring systems
Revised engine calibrations downloaded for the engine control module
Calibration modules which connect to the vehicle diagnostic connector
Modification to the engine turbocharger waste gate
Although the installation of these devices, or modification of vehicle components, can increase engine horsepower and torque, they may also negatively
affect the engine emissions, reliability and/or durability. In addition, other powertrain components, such as transmissions, universal joints, drive shafts,
and front/rear axle components, can be stressed beyond design safety limits by the installation of these devices.
General Motors does not support or endorse the use of devices or modifications that, when installed, increase the engine horsepower and torque. 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 dealer warranty claim submissions to 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. Refer to the
latest version of Bulletin 09-06-04-026 (V8 Gas Engines) or 06-06-01-007 (Duramax(TM) Diesel Engines) for more information on dealer requirements
for calibration verification.
These same policies apply as they relate to the use of non-GM accessories. Damage or failure from the use or installation of a non-GM accessory will not
be covered under warranty. Failure resulting from the alteration or modification of the vehicle, including the cutting, welding or disconnecting of the
vehicle's original equipment parts and components will void the warranty.
Additionally, dealers will NOT be reimbursed or compensated by GM in the event of any legal inquiry at either the local, state or federal level that