Ramsair

Hi All,
My extended GMPP warranty expired in December on my 06 C6Z so I had my heads redone in December and just took my car to get tuned for what I thought would be the first time. One of the best tuners in the Phoenix market hooked up his computer to do the real world road test before the dyno tune, and guess what????, my ECM is locked. He said that the car had been tuned in the past and the tuner locked the ECM. (I am the second owner since July 2010). So after the shock of realizing that I had been driving around under the false pretense of being covered under warranty – which I extended twice to the tune of $5k, I decided to do a baseline dyno… 4 pulls, with the best at 473 rwhp. My only mods are AHR stage 4 heads and a Halltech intake with beehive. The tuner said I could replace the ECM and only then retune the car, but given I don’t have any other mods I am feeling like 473 is a solid number. Your thoughts? ECM install + tune would run another $6 – 800 and I don't think there is much to gain in HP or Torque terms... driveability might be another story.

So, in year or two I might do a cam & headers...at that point I will need get a new ECM installed to be able to actually tune my car. Have to say that I am extremely disappointed in so many ways – but the silver lining is that I never had an issue with the motor and grateful that I did not need to attempt to use the warranty in that way, as we all know that GM would have voided any claim.

Chris

MTPZ06

Odd situation for sure, but I say leave it alone...its obviously been fine as is for all those years. If you tear into the motor down the line, you'll obviously need to deal with this; but plans can always change. While its good nothing happened to your motor under warranty, there could have been plenty of other problems that could have occurred. Be thankful you have a reliable car, and not a lemon. You bought the GMPP for peace of mind, and it sounds like that's exactly what it gave you all of those years.

Ramsair

Thanks - I did buy the GMPP for piece of mind... used it a few times on other things as well. If the motor had blown and they would not have covered it... something else would have blown up ... me.

MTPZ06

I hear ya there...my GMPP expires in April. Contemplating extending or buy a GMEPP. Either way, I went ahead and had AHP rebuild my heads under a GMPP claim last year. So at least I was able to get my money's worth...only paid ~$900 for a 4/48 major guard. Thankfully, no other issues with my car.

Unreal

$50-80 on ebay gets you an ecu. Shouldn't cost more than $100 to get a new ecu that isn't locked, or take yours to dealer and have it flashed to unlock it if you can find one to do it cheap.

Ramsair

Thanks - yes, spoke with Freeway - they said they could do it for $65... the tuner said not possible... so will tell the dealer that if they can I will pay, if not I won't and we will see. (worth a shot) If it works, then it will be back to stock and I will be back for a tune and will see if we can get more out of it than 473.

pkincy

That Tuner should be put out of business. I can see locking it where that file cannot be changed because that is his intellectual property but not so the PCM can't be reflashed. And I think that is likely what the dealer is going to do for you. Likely your local tuner couldn't do it because he didn't have a Tech 2 or a new stock file with your VIN in it.

Ramsair

I think you are right. To bad there is no digital sig on a tune... The other issue is that the tune was not disclosed to me when I bought the car. The dealer thinks it can be reflashed without an issue.

Unreal

Yep, dealer can flash it back to stock, no issue, then you can get tuned no problem.

I assume you are having Nic do it?

shane p

If some *** clown tuner locked the ecm I don't think any tuner can get into it even to download a factory tune from gm and start from there, you will need a new ecm for the car. I went through the same thing.

Michael_D

If you need a new ecm, the dealer would have to code the vin to it anyway, so you might as well see if they can re write the stock calibration to the current ecm, before buying a new one.

Unreal

Tech 2 can reflash a locked ECU.

HPtuners or EFi/etc cannot.

Or like I said, ECUs are $50-80 on ebay if for some reason dealer didn't want to do that.

Ramsair

Yes - he is the one that discovered it was locked. Says he sees stuff like this at least once a month.

Ramsair

Will be interesting to see if the dealer can reflash... will keep you in the loop. My dilemma is that if I reflash or replace the ecm, will I get a better tune than I have now ....

shane p

Let us know, I had to buy a new ecm then the tuner loaded in a factory tune from gm then the tuner can start tuning. problem for me was that I was 5 hours away from home I had almost 1000 bucks in a tune. I have a tech 2 but it was at home, I know the tuner got the car hooked up online with gm and tried to reload the factory tune and they couldn't get in either.

Unreal

Yes you will. I guarantee Nic's tune will be better than whats in there.

Ramsair

Just returned from Freeway Chev ~ NO Go on the flash... ECM is locked and I will need to replace it and start over.

Once a vehicle is tuned it is a 100% void of GM warranty on motor... REALLY glad I never needed to use my GMPP for that.

New ECM and program for securities, then headers and cam and then a tune... sometime in the near future.

Thanks for everyone chiming in. My only advice to anyone buying a used car, especially one still under warranty is to have the ECM checked before you give someone your hard earned cash. An integrity issue for sure - as the old adage goes, trust but verify.

Chris

MTPZ06

I wonder if your ECM has one of those "CoW Booster" upgrades...I think CoW is pretty secretive on that technology.

erick_e

Any possibility if finding out who tuned it previously? It's possible they could return it to stock and unlock it.

Unreal

Find a dealer that knows what they are doing.