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2007 chevy trailblazer_lt
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Discussion Starter · #1 ·
GM put a bulletin out to do the following EVERY TIME a car comes in for service for a tranny failure and engine failure problem.....Rear end included!!!


They are told to run the CVN numbers from the computer. These are pre-determined set values specific to your VIN.

Run these against the actual VIN based CVN numbers. If they do not match, they are told to VOID THE WARRANTY and a district service writer will come out to witness the difference.

This is on the Avalanches, Silverado's, Trailblazer based 360 platform, etc.

I hav had to go back and the dealer wanted to pull them up....Luckily, I had the tuner run it back to stock and brought it in for my Silverado. Trans fixed and tune re-installed.

Just a warning that GM is FORCING dealers to do this everytime. NO WARRANTY WORK CAN BE PREFORMED WITHOUT IT!!!!


Very few people can actually change the CVN's in the processor...a few can but remain anonomous... ( I know of two that I know).

Just be careful and possibly have a spare PCM with the stock file in it in case of a problem.


Just an FYI


Don

if you need more info, PM me...

DOn
 

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2002 chevy trailblazer_ls
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According to Feb 2009 Techlink the process to verify stock calibrations is now mandatory for any drivertrain failures. I think before it was just on suspect vehicles. They are apparently getting much more strict about this.

Excerpts from From Feb 2009 GM Techlink.... "Identifying Aftermarket
Non-GM Calibrations"

"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."

"In February 2009, PQC will begin piloting a process to confirm the ECM calibration is GM-issued. Beginning in February, PQC will require a picture of the engine calibration verification screen, as outlined in the bulletin, before authorizing any V8 engine replacement (both Gas and Diesel). If a non-GM calibration is detected by the dealership, follow the procedures outlined in the bulletin. Once documentation of the non-GM calibration has been received, and verification has taken place through GM, the remaining powertrain and driveline warranty will be cancelled and noted in VISS..."
 

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2007 chevy trailblazer_ss_1ss
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yea these posts are getting sooooo old.. they are all over tis site.. and plenty of other sites....

again it all boils down to your dealership and the relationship you have with them.. along with someone who KNOWS what they are doing when they tune your vehicle.. this is why i am opting out for the Dyno/street tune instead of mail order tune... if you have a problem.. boom right then and there it gets fixed.. plus certain tune shops deal specifically with TBSS' so they know what they are doing... rememebr in order to void a warranty the dealer must prove without a shadow of a doubt that the tune caused the part to malfunction...
 

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I would get any "contracts" with the dealer in writing though since even they may bail out if it means paying thousands for a repair.

As far as proof they'll always say GM's experience over yours. In reality they have lawyers on standby, where for most people it is just cheaper to repair the item.
 

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Discussion Starter · #6 ·
I'm no idiot

I know that the subject has been posted before (little button called SEARCH FUNCTION!!!!) I get it....

Anyway, what I was trying to say was that the GM dealers are being FORCED TO take a picture before any major service is performed. REGARDLESS OF YOUR RELATIONSHIP WITH DEALER!!! They will not get paid by GM if they do not do this.....When it comes to money, the dealer will do what they are told to do.


So, just beware....


Don
 

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2002 chevy trailblazer_ls
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... what I was trying to say was that the GM dealers are being FORCED TO take a picture before any major service is performed. REGARDLESS OF YOUR RELATIONSHIP WITH DEALER!!! They will not get paid by GM if they do not do this.....When it comes to money, the dealer will do what they are told to do.
So, just beware....
Don



And that's why I posted an excerpt from the Feb 2009 Techlink about the stepped up enforcement, to reinforce what blueblazer5_3 said. It's not a matter of GM proving aftermarket calibrations caused damage, all they have to show is the factory programming calibrations were altered or tampered with. Good Luck.
 

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2002 gmc envoy_slt
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I've read thru the different posts on GM's new policy and have a question/scenario. Say you have a PCM related problem and the dealer replaces/programs it under warranty. Then you have a powertrain problem while still in warranty. I know the tracking system should show the PCM has been replaced/reprogrammed but what if the Tech at the dealer didn't program the PCM correctly. This is all hypothetical and dealers have a way of manuvering around things.

As for the SS transmission problems the 4L60E was used in the Corvette and further back in the Z28/Trans Am. Yes the Trailblazer is heavier than the cars but if GM is using the standard trans instead of the one with upgraded components then they will experience failures. GM had problems with this trans when it was introduced in '82 as the 700R4. It took them 5 years to iron out the pump failures among other problems.
 

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2003 gmc envoy_slt
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I may be wrong, but I think the SS uses the 4L80E. The I6 and 5.3 use the 4L60E.
 

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Discussion Starter · #11 ·
There are ways

There are ways that the dealer can see if there is an issue....Fan speeds, base timing, etc.


All I am saying is that if you wanna tune, go to a guy who can tune it so GM can't see it.

Again, Just an FYI....

DOn
 

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Or do what I did, I got a tuned PCM from PCM 4 Less and kept my OEM PCM. It literally takes 5 minutes to swap them out. Plus I still keep my OEM one in my truck.
 

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Thank you BoricuaSS and WOOLUF for the correction on my statement of the 4L60E in the SS. I was under the assumption this is what was being used and hence the problems (is the 4L70E some sort of hybrid or a new trans).
 

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2007 chevy trailblazer_ss_1ss
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Or do what I did, I got a tuned PCM from PCM 4 Less and kept my OEM PCM. It literally takes 5 minutes to swap them out. Plus I still keep my OEM one in my truck.
how are you able to do that.. i read that the PCM can also keep milage based on the computer..that dealers can tell when they flash the PCM they will notice a difference??? like i said it was just reading on here and other sites so who knows.. but that is a safe way to go...

Thank you BoricuaSS and WOOLUF for the correction on my statement of the 4L60E in the SS. I was under the assumption this is what was being used and hence the problems (is the 4L70E some sort of hybrid or a new trans).
Well i dont know if it is a hybrid tranny but it sure is S****Y.. tons of people blow them up in TBSS' some due to normal wear and tear (as early as 10k miles) most others due to mods...all i can say is i already started saving for my aftermarket tranny (the RPM's tranny).. now mind you this is based off of the people that post up "tranny problems", of course you never hear the glory stories or how someones TBSS has 100k miles and not a single problem..so who knows...
 

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2003 gmc envoy_slt
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yes you are wrong the SS has the 4L70E transmission...well at least my SS does :thumbsup:
See. Shows what I know. I didn't know there was a 4L70E. I learned something today.:thx
 

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how are you able to do that.. i read that the PCM can also keep milage based on the computer..that dealers can tell when they flash the PCM they will notice a difference??? like i said it was just reading on here and other sites so who knows.. but that is a safe way to go...



Well i dont know if it is a hybrid tranny but it sure is S****Y.. tons of people blow them up in TBSS' some due to normal wear and tear (as early as 10k miles) most others due to mods...all i can say is i already started saving for my aftermarket tranny (the RPM's tranny).. now mind you this is based off of the people that post up "tranny problems", of course you never hear the glory stories or how someones TBSS has 100k miles and not a single problem..so who knows...
The ol' 4L70E, what a under capable trans this is for the 400ft tq LS2 coupled with a 4600lbs truck. Throw in AWD, and the problem multiplies even more. Its an upgraded 4L60E, supposed to hold more power than the 4L65E too with some more internal upgrades. But we all know how easy it is for the LS2 to smoke them stock.

As for tunes, I want to know from someone with a Tech II (no speculating, I want someone who has checked it themselves) if it can read mileage. If it can, guess we're all SOL.
 

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I not aware the pcm retains mileage. I think it is in the ipc. I've replaced dozens of pcm's, ecm's and bcm's in various GM vehicles over the years and haven't had to reprogram mileage, except when replacing the ipc. I have a tech 2, while not remembering seeing mileage when using it, I'll scroll through the screens and see if it is in there. The following statement is an educated guess, not based on any facts until I hook up my tech 2: yes, it may show mileage of the vehicle, it may not be based off of the pcm but the ipc. So, unless the ipc was replaced, mileage should be the same regardless of when the pcm was replaced.

Mark
 

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Or do what I did, I got a tuned PCM from PCM 4 Less and kept my OEM PCM. It literally takes 5 minutes to swap them out. Plus I still keep my OEM one in my truck.
how does this work? i thought yu send yur PCM to them and they send it bak tuned? :undecided

good thing i saw this since im startin to save up for my tuney :bonk:
 
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