This was on another board concerning GM tuning.....thought you may want to know this.

It was concerning an '06 Trailblazer SS. 6.0, with multiple engine/piston failure in Ca.
In investigating the failures, engineering started to look into the possibility of aftermarket/re-written calibrations, even though the cal id # shown in data was current.

After many repeated attempts by engineering to "decipher" the internals of the program, and months of begging and pleading from Powertrain on this and other "unexplainable" failures, the Delphi and GM (software) engineers finally decided to allow Powertrain engineering access to the actual software programming.

What that means is FOR THE FIRST TIME, GM Powertrain Engineering can look at actual parameters in each subsection of programming, and make side-by-side comparisons of "factory" vs "as programmed"....

Now, what does that mean?

Until TODAY GM Powertrain Engineering could not SEE every individual, specific change...bits and bytes...in every part of a program. They had no way to PROVE a calibration change...except for Cal ID#...and then, they could NOT deny major warranty work if challenged (court/attorney) or Arbitration Board.
It was impossible for GM to prove anything except for speculation...

BUT, with Delphi and GM's Computer Programming/software changes, they will have complete access to comparitive data.....

Because of this, they were able to PROVE this truck had changes to torque limits, spark retard/advance, fuel block counts, evap turned off, egr ramp profile changes, rpm limits raised, a/c command limits blocked, ect....and WON in front of an arbitration board.

This has already had fall-out inside GM. Apparently, winning this case PROVED to GM heirarchy that changes were needed in programming systems. Due to the # and frequency of failures concerning "suspect" programming changes...they have already started to develop a new system to debut in (supposedly) late '08 and '09 vehicles.

The new software will be encrypted differently, have "rolling" changes to encryption, and store values for only 10 software changes or updates...any and all CHANGES to the software will be stored seperately in memory...so comparisons can be made in case of a major component failure. After 10 changes, the ecm will "lock" and operate only on the original software cal. This feature is supposedly to prevent someone from "storing" and "re-loading" an original program. If you were to "rewrite" a program, it would store the original data, then the changed data, and then any re-writes of the original program.
All this would be retreivable by accessing the ALDL and requesting the changes to compare.

Also, he mentioned that, starting in mid May/June, ALL '07 and later vehicles returning for any warranty work that involve connecting to the factory TIS programming system will AUTOMATICALLY have ALL accessible computers/modules checked and verified for any needed updates.....SO, if you have a "hot" pcm recal, it will notify GM and Dealer personel of the "needed" changes....and possibly REQUIRE dealers to recalibrate any changed stuff.

And YES, its legal.
It falls under the Federal Emissions Laws. The factory can, at any time a vehicle is being serviced, check/verify/change ANY and ALL emissions devices it deems necessary, so long as those changes have been verified by the EPA. If it can make a change in tailpipe emissions, they are bound by law to make it work as produced.

 

very interesting. not surprised though.

 

man hot topics make their way around the net quickly lol

 

Well...I already heard this and knew about it but this is just a good write up on this.

The LMM already has this program according to GM.

 

So, if you make tune changes, break something, GM can deny your warranty because they know you changed the tune. Correct?

Do they have to prove the tune change caused the failure?

Flamesuit on:
You have to expect something like this. Scenario: A guy buys a new Vette/Silverado/GTO, puts a 150 shot on it and fries a piston. Then he pulls the kit off, sets the tune to stock and drags it to the dealer for a warranty engine and claims he doent know what happened.

Can't say I blame the dealerships/GM.

Are HPT and EFI gonna be able to break the code is my real question

 

so, just get a spare pcm and tune away.

still sucks to hear though

thanks for the info

 

Hmm, sounds easy enough

 

Doesnt effect my current vehicle but for the future its good to know. Sounds kinda like the Dodge setups with the revolving code. People are getting around the Dodge tuning issues now... Sooooo...

 

Why would you think your entitled to GM fixing a broken piston because of a bad tune? Or even a tune that made more power than their engine/tranny was intended to handle?

Why would you think we would want to challenge GM so that you could do so? Wouldn't this be endorsing fraud for us?

Bottom line is if your going to mod your vehicle you should be prepared to pay for broken parts caused by this.

-Bill

 

Umm, I hope that was a general statement and not directed at me. I don’t, and haven’t, ever expected that. It is a scenario I have seen people try on this and other boards. I have been through 5 transmissions, 3 engines, 2 torque converters, and a driveshaft on my own dime--- while still under warranty.
You break, you buy. That’s all there is to it. I’m saying I understand why GM is looking for a way to NOT warranty abused cars/trucks.
I want to know if HPT and EFI will be able to still tune PCM's with a rolling code or locking PCM's. Like you already do with current PCM's.