Well, it's happened. If you mod your PCM, you have just invalidated your warranty!
See the excerpt from the PDF Below:
"#09-06-04-026: Identifying Non-GM (Aftermarket)
Engine and Transmission Calibrations for V8 Gas
Engines - (May 18, 2009)
Subject: Identifying Non-GM (Aftermarket) Engine and Transmission
Calibrations for V8 Gas Engines
Models: 2006-2009 GM Passenger Cars and Light Duty Trucks
(Excluding Saab 9-7X)
2006-2009 HUMMER H2, H3
Equipped with V8 Gas Powered Engines Only
Attention: This bulletin applies to V8 gas powered engines ONLY. For all other gas
powered engine applications, refer to Corporate Bulletin Number
08-06-04-033D. For diesel powered engines, refer to Corporate Bulletin
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 is 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 (aftermarket) issued 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.
This bulletin outlines a procedure 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 May 2009, the PQC will begin piloting a process to confirm the ECM/PCM calibration is GM issued.
Beginning on May 18, 2009, the PQC will require a picture of the engine calibration verification
screen, as outlined in this bulletin, before authorizing any V8 gas powered engine replacement.
If a non-GM calibration is found and verification has taken place through GM, the remaining
powertrain and driveline warranty will be cancelled and notated in GMVIS and the dealership will be
This is a GM memo, meaning no matter what GM says you still have the same rights under the Magussen Moss Warranty act, they must prove the modification caused the failure. Magnussen Moss is a Federal act they have to abide by it doesnt care what any auto manufacturers internal repair decisions or memo's say.
This particular memo also borders on Federal Clean air acts regardiing catalytic convertors and emmissions parts which are pretty cut and dried and they have no grey area to deviate from.
Some people will be shown this memo when getting repairs at the dealership and assume it means they have no warranty, that would be a mistake on their part, they need to persue the issue with a mediator if this happens.
This is also why you never make a change to a warrantied vehicle that cant easily be changed back to stock prior to bringing the vehicle in for any servicing even something as simple as an oil change, if you dont think the dealerships arent checking and documenting modifications of any type to your vehicle your mistaken.
they must take a picture of the cvn # (Calibration Verification Number ) this changings everytime you reprogram it must match what they have in the ivory tower if not bad news
You bring up a very interesting point. The CVN does change when a programmer is added. I'm wondering if the programmer changes it back when you perform an uninstall of the program?
Originally Posted by sgui
Yes thats one of the methods being used for tracking but it goes back to the fact that they have to prove what you've been doing and why it was recalibrated. With so many repair shops doing diagnostic and repair and almost none of them reporting back to GM on why a recal was done it would be almost impossible for them to know exactly who and why this was done.
Originally Posted by sgui
When you uninstall the program it registers a change and assigns a new number, so they'll always know you changed something but not what you changed or why you changed it.
Originally Posted by tbplus10
Many aftermarket repair shops have the reprogramming pass through hardware and actually purchase the flash program from GM. So to be safe one could always remove his programmer and then have his PCM re-flashed with the latest programming before taking it in for a warranty repair. Especially if the programmer was set to high performance and something is broken because of it.
Yep, that would be the smart move, then let'em prove you werent running anything but stock settings.
sorry to say it doesn't change back as for sps you have to get a subscription from gm in order to program j2534 is what the aftermarket uses i think even that is connected to the ivory tower. them tuner people better get it together imho.
let me try to answer this as a former dealer they can refuse to fix under warrenty if it changes the specs of what the car/truck was designed for if you change say a gm hub with a napa hub they will not cover it since it should be covered by napa but will cover any other item that has not been changed or modified..ask your self if you were in buisness and someone changed something that changed what you built and it wasnt designed to be that way would you cover that change
true but just like computers in your home a reflash partichans the computer and they can see any and all changes you have made or changed nice try
Originally Posted by Jimmiee