If a tune is flashed onto a computer can it later be flashed back to stock specs where its undetectable that a tune was ever done? I heard that if you tune the factory ecu it creates some file that can not be deleted that shows the tune was tampered with, is that true?

Thanks

 

I have no idea but it wouldn't surprise me. It could protect GM in case of some EPA type lawsuits if it logged access date/time. They could compare to repair records and show if it was 'authorized' by a dealer. I do know that on my Jag the tech could tell how many times the ECU had been accessed and also the version of each reflash. (It went through several "updates" with the ECU software by Jaguar) He showed me the readout on his screen.

 

Do a search on tuning. That has never come up in anything I have read. Folks tune all the time on here. As long as the modified tune code isn't locked you can modify it and the original program can always be reflashed putting you back to stock.

From what I read here it's done all the time.

 

Our new Duramax diesels keep the last 10 calibration numbers too. AFAIK that is the only GM ECM with that ability right now.

 

yeah just want to make sure it can be done, i wouldnt want to lose a 10 year 100k warranty on my car for taking of TM or tuning for headers

 

Shopdog posted awhile back that GM can see that a tune was done and flashed back to stock but they most likely would never see it. They would need to be looking for it.

 

I'm no tuning wiz, but couldn't someone just flash the ECM 10 times with the stock tune to get 10 stock calibration numbers stored?

 

If it really worries you, you could always buy a spare ECM - it would be stock.....

 

I think the new ECM would then need GM to flash it

 

What would that entail, or could Chuck COW do it? He has stock tunes stored I'm sure.

 

Yup, he can flash a stock tune in a PCM...usually they come with a stock tune. I don't think you could buy a blank PCM....The biggie is for the PCM to match your car application, that is where Chuck comes in, matching the PCM to your car, or flashing your factory stock tune in to the new PCM.

 

If you mean buying one from a dealer, they do come 'blank', no calibrations are preloaded.

 

how much is a spare pcm? i guess you can get one out of a wrecked car, are they locked into a vin number or anything like that?

 

Correct....They actually come with an operating system so they can test it when it's manufactured...but there is usually no calibration......

Most often in E38 (06 and later Vette computers) are manufactured and tested with an 07 Suburban operating system.....

Kinda Wierd doncha think?
Chuck CoW

 

The dealer does not have the capability to determine if the tune has been changed. There is also no reason for them to reflash unless there is a significant update. If that is the case hopefully your tuner will be kind enough to reflash it back!

Howard

 

This is why, in my opinion, having your tuning done locally, and/or having your own tuning hardware/software is the best idea. You never know when you might need some kind of warranty work and/or update required and the potential to have your warranty claim denied because of a "tune" discovered or worse yet, a "locked tune" or "locked PCM/ECM". Having your local tuner who can change your PCM/ECM back to stock form prior to going in to the dealer, or having your own tuner software to change back to stock assures you of no problems at the dealer when it comes to the PCM/ECM. Food for thought, especially in light of the #12 thread I just read below!!

 

the NEW OBDII software for cities and counties that require smog testing, will have that ability very soon.

The new OBDII software will first determain if the tune is stock or has been modified. If the tune has been modified the OBD computer will check its data base to see if the Manufacture as supplied a stock tune to the OBDII software company, then the computer will reflash YOUR tune to stock. Then run the diagnostic too check for codes. Plus put a note in that cars DMV file that the tune was changed.

If a OBD computer does not have a copy of the manufactures tune it will red flag your car, and your car will fail. Then you have to get a retune to stock and retest your car.

Unfortunitly my state of North Carolina will be one of the first states to have it. So off to the tuner BEFORE the OBDII emissions test in May then back to the tuner to retune after the emission inspection

What a PIA

I like that Duramax diesel puter. To bad they dont get inspected.
I thought about the Bosch Motorsports Sport PCM that can hold multiple tunes, but $5,000 for the economy model was a bit out side my budget

 

That has been true so far, but see what just came down with the diesels as GMautotech stated. Seems this is the way things are going to be going.



Information on Identifying Non-GM Calibration Usages for LMM Duramax Diesel Engine #08-06-04-006 - (01/25/2008)



Models: 2007-2008 Chevrolet Express, Kodiak, Silverado

2007-2008 GMC Savana, Sierra, TopKick

with 6.6L Duramax® Diesel Engine (VIN 6 -- RPO LMM)



Attention: Dealerships should remind their customers that engine concerns due to non-GM calibrations (Power-Up Kit) will not be covered under the GM warranty.



--------------------------------------------------------------------------------

Power-Up Kit Detection
For 2007-2008 applications, an Engine Control Module (ECM) algorithm was implemented that records the engine calibration part number and Calibration Verification Number (CVN) for the last 10 flash programming events. The ECM only records the engine calibration part number because it contains the parameters for increasing torque and fueling rates.

Customers may have re-programmed the ECM with a non-GM released calibration. Power-Up Kit calibrations change fueling and timing parameters and may contribute to the following vehicle symptoms:

• Poor Performance

• Black Smoke (This symptom is not valid for the 6.6L (LMM) diesel equipped with the diesel particulate filter (DPF). The DPF will trap black smoke unless the DPF is cracked, melted or has been removed from the exhaust system.)

• Knocking Noise

• May Cause Engine Damage

If a customer vehicle comes in to your dealership with possible symptoms from a Power-Up Kit, the dealership technician may now read the last 10 engine calibration part numbers and CVN history using a Tech 2 ®.

The dealership technician would input each ECM calibration part number into the SPS/TIS2WEB CVN database to confirm the CVN history information. Refer to Tech 2 path table in this bulletin to verify ECM calibration.

 

Thats very nasty by the smog police!! This means those with headers are in for a bad time, what with the CEL's they'll throw when put back to stock tune. We'll have to take 'em off and put them back on along with changing the tune! Like I said, you'll need a local tuner, or your own tuning hardware/software. Say bye bye to "locked" ECM's too.

 

Think I will just wind up buying another ECM. Keep one semi stock with all the stock tunes and codes and the other with the tune. Ol plug and play