08Z06JSB

The tuning topic seems to have its place on the forum. In my short time watching and reading I have seen quite a few threads on the tipic many of which weigh the tune vs. warranty. I have seen the phrase mod-friendly dealer quite a few times as well. That said, I was curious how the local dealerships would react to mods and started asking around at a few so as not to upset the proverbial apple cart. I got an interesting response from one of them yesterday.

Has anyone seen a bulletin from GM dated May 18, 2009 (Bulletin #09-06-04-026)? If this has already been discussed please disregard the post...if not it outlines a referencing procedure for the dealerships to verify there has been no aftermarket calibration on GM-released products - specifically as GM states "Engine and Transmission Calibrations for V8 Gas Engines" - when a warranty claim is made on any "hard part failure". It says 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".

Please understand I am no expert on tuning for sure. I just happened to get some interesting information. Any thoughts?

PS - anything underlined above came directly from the GM bulletin.

tjwong

Thats old news. GM has been verifying engine calibrations for the last couple of years now. Especially in the diesel trucks, in fact that is what really started it all. Because there was so many failures with the Duramax trucks for power hungry owners that add power adders to their trucks GM had to do something. So it all carried over to the car line ups as well. Attached is the actual GM bulletine for those that want to see it. The main issue stated here in this bulletine is that it states that GM WILL CANCEL ANY REMAINING WARRANTY if an aftermarket cal if found in the PCM.

obzidian

Well, that is if they can even find it or any trace of a tune.

08Z06JSB

Thats old news. GM has been verifying engine calibrations for the last couple of years now. Especially in the diesel trucks, in fact that is what really started it all. Because there was so many failures with the Duramax trucks for power hungry owners that add power adders to their trucks GM had to do something. So it all carried over to the car line ups as well. Attached is the actual GM bulletine for those that want to see it. The main issue stated here in this bulletine is that it states that GM WILL CANCEL ANY REMAINING WARRANTY if an aftermarket cal if found in the PCM.

I agree that the discussion of whether or not GM would try to void a warranty seems to be old news but I had not previously seen an actual bulletin outlining steps to the dealership whereby GM would verify whether or not a tune had been installed.

As I mentioned, I am far from informed in this area and the threads have been a big help in gaining knowledge and understanding. I guess the fact that the bulletin was issued on May 18, 2009 made it new news to me. With the financial situation at GM it makes sense that they would tighten up anywhere they can.

Well, that is if they can even find it or any trace of a tune.

This is the part that I still do not understand. I reprogrammed my Duramax about a year ago and it needed to go in for repair soon after. I put the computer back to stock and they told me they could tell it had been flashed. It was out of warranty so it was no big deal but I thought it was interesting they could tell...maybe I did something wrong?

08Z06JSB

My previous post was not very clear I should have previewed it...sorry.

I agree that the discussion of whether or not GM would try to void a warranty seems to be old news but I had not previously seen an actual bulletin outlining steps to the dealership whereby GM would verify whether or not a tune had been installed.

As I mentioned, I am far from informed in this area and the threads have been a big help in gaining knowledge and understanding. I guess the fact that the bulletin was issued on May 18, 2009 made it new news to me. With the financial situation at GM it makes sense that they would tighten up anywhere they can.

This is the part that I still do not understand. I reprogrammed my Duramax about a year ago and it needed to go in for repair soon after. I put the computer back to stock and they told me they could tell it had been flashed. It was out of warranty so it was no big deal but I thought it was interesting they could tell...maybe I did something wrong?

Steve

JT Metal

Rightfully So!!!! Everyone thinks thier smarter than GM. They are one of the few companies that put a large displacement engine (427) into a production car allow you to push it to 7000rpm's and give you a 5yr/100000 warranty.....Totally unheard of!!!!! But you seem to think you (people in general) need the extra 20 or so ponies. So I say mod away..........

obzidian

Well, that all depends on how you tuned that duramax and if the person who developed the tune was able to hide it well... which isn't too hard, really.

gonzalezfj

Yes, we know GM engineers are stupid...

There are several methods to find out you have screwed around with a digital file, even if you think you are smart and try to put it back the way it was originally. Just for laughs, look up "digital signatures".

Frank Gonzalez

corvette-pilot

They left plenty of room for improvement but have to balance performance against the warranty. Why should GM pay for warranty work when people start messing around with stuff they shouldn't.

RADAR B8

Has anyone had their remaining GMPP warranty cancalled due to an after market tune?

JT Metal

Right on Brother!..............

Pistol Champ

So now everyone will take a photo before they tune their car and keep it for reference for their friendly dealer to use. This sounds wrong to me.

'06 Quicksilver Z06

Good info.

Of course there are still going to be those who want to argue and insist that they can return their cars back to stock or "better yet" buy a second ECM to put into the car in the event of a needed warranty repair.

joe11204

There was a rather lenghty thread on your exact question...

http://forums.corvetteforum.com/c6-z...-ecm-mods.html

.

tjwong

There has been several instances of this, I know of two in my area that had their warrantys blocked as a result of non GM cals.

Duramax PCMs are different than the E38s that are used in our Corvettes. They have a counter that dings everytime its been reflashed. So even though the perp will reflash it to stock, thus making the CVNs something that GM recognizes, the PCM will still display how many times its been flashed. And if its under warranty, the dealer will have a record of it being flashed, and if it shows being flashed 5x and they didn't do it, bingo they got you.

In our cars, all they need to do is to verify the CVNs (calibration verification numbers) to what is published by GM. When an aftermarket tune being from a tuner using Hp Tuners, EFI Live, or others, the CVNs change when the PCM is flashed, consider the CVN number as a complex check sum. No matter what you do the CVN will always be different if its not a factory GM cal. That is how they catch you, I posted the actual bulletine the proceedure is outlined clearly in the document. Sure you can beat it with a second PCM, but if they see headers thats another no no, a cam well thats pretty obvious most people with those kinds of mods don't care about their drivetrain warranty anyway.

My car was less than 6mos old when I invaded the engine by swapping the cam and heads out, the cam was swapped 3x in order to find a cam I liked. The heads were extensively worked over by LPE. I need a wheel replace because the chrome is starting to bubble, that will be replaced under warranty, as for the engine not any more, and I don't really care. I got another LS7 block and a complete Callies rotating assembly with Arias pistons sitting here waiting to be massaged by the machine shop, its getting a TTiX kit on it once the engine is done My goals are around 850 WHP, I don't think they will honor a warranty on that either

joe11204

Tj, I'm sure you are aware that EFI Live has a feature to Reset the CVN's back to the factory reading by adjusting the checksum data. I'm sure that at the dealership level this would be the end of it. As I remember it, the TSB was to have the dealership compare the PCM's cal to the Factory CAL and if their was a mismatch their would be a problem otherwise it would appear stock.

But like you said, with the ability to now swap out with a 2nd PCM that CVN issue is a moot point.

RADAR B8

That post talks only about GM factory warranty, I was asking about GMPP ext warranty.

joe11204

I missed that. The GMPP is not an extended warranty. It is a service contract. I'm sure the same issues would / should apply. I had one on my 2005 coupe, I will check it later to see the VOID section. LOL

BTW. From what I was told from Chuck Cow, a supporting CF tuner and repair shop. If you have a GMPP and need service, he can repair your car for you and GMPP will reimburse him. You don't have to bring your car to a dealership. You can have a corvette repair shop take care of your car.

tjwong

Well, I am not so sure they still offer it. At the time it was available a couple months ago, a tuner would have to buy a full stream license which is 2500+ per stream, a stream would cover every make and model that say a E38 would be used in. Which is a lot of cars. Also their stream licenses has to be purchased for the TCMs as well, so that means that in order to do all corvettes you have to buy 4 stream licenses, I looked into it at one time, and the cost would have been about 8k for me to switch from HPT to EFI Live. I am still thinking about it but thats a lot of dough, I can buy a TTiX kit for my car for that amount of money which I am about to do so that is where my dough is committed to.

However like I mentioned earlier, for the guys that has cam and head cars, blown cars or other heavy mods, it is moot as well because these guys know that there powertrain warranty is history anyway. It only applies to those that have tunes only and their cars are basically stock. I have seen GM deny warranty just for having headers, it happened not long ago at a local dealer to a Z owner that I know. There was other factors such as prior history of abuse where it was denied as well. But it does happen.

tjwong

With a GMPP extended warranty you can take it to virtually any repair shop be it a GM or a independant. Of course they would love to have you go to a GM dealership. I have even had GMPP claims through my shop. The main reason is because it is much like an insurance policy where you have body damage and want it fixed, you can take it to any body shop of your choice. I am not sure how the GMPP warranty would handle aftermarket cals or aftermarket performance parts, I would suggest reading the policys "fine print" very carefully.