Non-GM Engine Calibrations

General Motors does not endorse the use of aftermarket (non-GM issued) engine calibrations in any of its gasoline or diesel powered vehicles in North America. When non-GM issued engine control calibrations are detected, steps should be taken to void the Powertrain portion of the New Vehicle Warranty.

Bulletins 08-06-04-006A (diesel engine vehicles) and 08-06-04-033 (gasoline engine vehicles) outline the procedures to be used in identifying the presence of non-GM issued calibrations. Non-GM issued engine calibrations subject driveline components to stresses different from the calibrations to which these components were validated. The stresses resulting from the non-GM calibrations and equipment were not validated by GM and therefore cannot be warranted on any components that are subject to those stresses.

Where a non-GM engine calibration has been verified, current and future repairs to engine, transmission, transfer case, driveline, axle and/or other driveline components are not covered under the terms of the New Vehicle Warranty.

GM TechLink August 2008

 

Welcome to a month ago

At least people that didn't see / know it before now do

 

Old news for sure, they won't warranty any drive train after a head and cam install either but then again do you really expect them to. I modded the heck out of my new Z, and I really don't expect them to cover anything. However they did cover my memory seat module that went south causing my telescopic steering column mechanism to be inoperative. There is another tuner that can suposidly tune your car so that its not detectable. However if the GM Tech was sharp, he would know that something was changed such as when the cooling fan comes on because most tuners will install a 160 thermostat and turn on the fan at a much cooler temperature. Also shift points, the stock shift points are well documented in their service manuals, another is that is when the tuner LOCKS the PCM which prevents a rewrite. That is a sure give away, at which then the PCM could be removed and sent to GM PT Engineering where they will dissect it and discover its true contents. This would likely happen only in case of a catastrophic engine failure which in some cases has happened especially in the diesel crowd. The bottom line is if you want to keep your warranty intact, leave the car alone. The old saying of "if you play, you pay" surely applies here. GM has really got tough, after all they just had another quarterly loss that is more than some countries GNP! So cutting costs and managing their monies better is of the utmost importance.

 

One of the older threads on the subject here I read a few months ago (IIRC) questioned whether GM could detect if a restore was done (for example a predator restore of original backup) - I know I read a comment from Mike at Diablosport saying (IIRC) after a restore it was like it was never touched, but I don't know for sure if that's true (i.e. is there some memory/counter address that keeps track of the # of flashes that cannot be reset...)

 

 

 

I would like to know the answer to that too. I would like to lower my fan setting. If I then turn it back to stock will GM be able to detect that it was changed at one point? A fan setting wouldn't be cheating GM if my engine or part of my drivetrain failed.

 

GM can put this in any bulletin they want to, but the truth of the matter is that the Magnuson-Moss Warranty Act prohibits the voiding of any warranty or portion of a warranty unless the warrantor (in this case: GM) can PROVE that the defect was caused by the modification. In other words, a "tune" will not necessarily void any part of the manufacturer's powertrain warranty UNLESS it can be PROVEN that the tune was the cause of the damage.

From the Magnuson-Moss Warranty Act: The federal minimum standards for full warranties are waived if the warrantor can show that the problem associated with a warranted consumer product was caused by damage while in the possession of the consumer, or by unreasonable use, including a failure to provide reasonable and necessary maintenance.

 

Supposedly a GM tech can detect a trace that something was done to the car when they plug it in.

 

from what i understand 2008+ silverados have a flash counter however 2008 and earlier corvettes DO NOT, it's unknown if the 09 vettes have a flash counter.

 

Here's the fly in the ointment. GM or whoever can decline your warranty claim for even the smallest, silliest, most bogus of reasons. Now, what is the car owner to do. Sue? Right.....When they decline your warranty claim, you're pretty much screwed. Hire you a lawyer and go against GM. Good luck. They have their warranty.....if you want to get it and they don't want to give it up, you have to beat them in court. They have ambulance chasers on the payroll that have fought this battle a time or two. When you square off with GM, it's battle of wallets. Who has the bigger one?

 

too bad not all tuners are as honest as you. you have my respect.

 

But can they detect if it had been returned to stock?

 

not on the E38 2008 ecu from what i'm told and what EFIlive/CoW says

 

Our warranty is safe then to change our fan temps long as it's returned to stock before visiting the dealer. Prior tuning cannot be detected according to Chuck/CoW?

 

yeah it doesn't have a checksum/flash counter function i'm told, but the 08+ silverado does and i'm sure they're working to defeat that (or already have)

 

My luck they would have an 08 ecu flash counter working by the time my tranny, etc. failed. It's hard to give up a 5 year warranty just to keep from seeing 220* on my DIC. The normal 198* seems awfully high. Heat does take an eventual toll on hoses and other rubber goods under the hood. Awful tempting to go ahead and make the change.

 

As long as a factory GM cal is reflashed into the PCM, then when the PCM is que'd via a tech2 to divulge its calibration verification numbers they will come up on the tech2 as GM issued. Any and I mean ANY MINUTE change to the PCM code that is not from GM will end up with a CVN that is other than a GM number, that will set off the alarm to the dealership. If at that time that a car is in for repair of a major failure and a non GM CVN is discovered, they will likely NULL and VOID your warranty depending on what happened. Lets say you shattered a piston, and your PCM dumps out false CVN id numbers to the dealer, you can bet the shirt off your back that GM is going to question the coverage. Their position on this right now is that if a catrastrophic failure occurs, the dealers are directed to check the CVN ID numbers in the PCM, in case they are found to be non GM, they are directed to take a digital snap shot of the TECH2 displaying the non GM numbers along with a screen shot of their TIS2WEB calibration ID screen, and to email them to GM's warranty manager, who makes the ultimate decision on whether they will or will not pay for the repair.

I have tuned a few 08 trucks and have not seen this flash counter, do you know where it suposidley resides?

 

This very thing happened to a guy I know. He was driving a new Z06 (2006) from Anaheim to San Diego on the Fwy. He made it to Rancho Bernardo and a valve spring broke, causing the valve to smack (and shatter) the piston. This caused the block to become "air-conditioned". Once off the flatbed at the dealership, the tech leaned in and "shot" the steering column with some tool. It gave a readout of all pertinant data. Oil pressure, RPM, oil/coolant temps, highest RPM during the ignition cycle & other things. He said, "It's covered because there were no mods nor abuse". Since then, the owner dosen't drive the black Z06 (this one) but thrashes the red Z! The car sits in Spokan now...undriven.

Point of this little story is that YOU are in control of your warranty. You can preserve it or destroy it. It's up to you.