GMPP Stage 3

[soccer1061287]

I have the GMPP stage 3 cal in my car. The processor in my car came out of a 2004 5 cyl Canyon. It is a P12, so no problem flashing the stage 3 into it and my original processor has the GMPP Stage 2. My problem is that I cannot buy a license for the stage 3. The best I can come up with is that the processor thinks it is in a Canyon and that the two VINs do not match. All I am trying to do is turn my air conditioning back on, which stage 3 disables. I think it is Bill at HP tuners that was trying to explain why I cannot modify this cal, but the explanation did not make sense to me. He kept saying something about the operating system being wrong. Can anyone out there put this in english so I can understand why I cannot modify this perfectly legally owned processor and calibration?

[bc3tech]

so you're trying to read the stg3 that's in your car, which came out of a Canyon, then put that into your original ecm, which has stg2?

which one can you read, and which one can't you?

[soccer1061287]

I have not tried the stage 2 which is the original piece of hardware from the car. I can read the stage 3 cal that is burned into the Canyon processor that is currently in my Cobalt, but I cannot buy a license or modify that cal.. What I want to do is turn the A/C back on on the stage 3 and keep it in the car.

[Julex]

Ok basically what he's saying is HPT THINKS it's a Canyon PCM but in reality it's probably a Standalone GM created for the stage 3 so that they could add features to help run nitrous etc. Basically the Stage 3 is a different PCM and HPT does not support it yet, or if at all. I thought the Stage 3 was a box where you can switch between Stage 3 PCM back to the Stock PCM. Maybe I'm incorrect in this. But basically Your kind of out of luck at this point with the Stage 3 PCM unless you can switch to your stock one, and just tune that.

[soccer1061287]

The GMPP stage 3 cal would normally be flashed into your stock PCM, but I wanted to keep my stage 2 which was flashed into the stock PCM (and did not at the time own HPT), so I purchased the Canyon PCM which also a P12 processor just like the factory original. Unfortunately, the VIN must be hard coded into the processor, because HPT knows that the processor came out of a 2004 I5 Canyon and not a 2006 Cobalt SS/SC.

[soccer1061287]

BTW, this processor actually came out of a wrecked 2004 Canyon I5 and with the stage 3, you cannot switch back to stock cal, but you can turn on and turn off the 100 octane cal and you have to wire into the PCM pins to access the Nitrous Cal.

[Julex]

If GM flashed the PCM with a stage 3 tune to your car, it would have been set to your VIN number, if they didn't do this then that alone would be a problem, The other thing is I don't exactly know how switching car pcms while being the same but run NA and other with boost, I would think the Supercharger tq settings wouldn't even be there. I don't know. But if Foff says you can't then I'd be willing to bet you can't.

[soccer1061287]

GM flashed the cal, but not at a dealership. One of the calibrators flashed it standalone off of the car, so I bet that is where the problem lies. I need to get it flashed on the car so that it will pick up my VIN.

[Doc.SS]

I don't believe the stage 3 is available via a flash, its the computer or nothing. Takes a few minutes to unhook the harnesses and swap out the unit. When I read mine, it didn't show anything (OS, CAL, VIN) so I kinda gave up trying to get it read. I debated on sending it in to get looked at.

[Julex]

Realize that it's not a bad computer it's just not supported by HPtuners, and I doubt it will be as it's not a stock component, same thing with the newer model cavalier supercharger reflash.

[Jayson]

what are the chances that HPtuners would be able to work out the kinks with the stage 3 PCM in the near future?

[Julex]

99% is never, since they only do things to stock ECMs. But, I'll let a HPT Rep confirm that. Sorry

[Jayson]

damn is there a way to mimick the stage3tune? Cause its not really the tune im after, its the on the fly map table switches and user adjustable rev limiter. Would it be possible to make something like that for our stock PCM using HPtuners?

[Julex]

Yes. That's the whole point of HPT is to adjust all the ECM settings. Because of the PCM data transfer it only takes 44 seconds as soon as you hit start, and you have a new tune. Stage 3 is no better then a HPT tune, and in almost all cases, it's better.

[Jayson]

well im looking for a way to do it so i dont need to lug around a laptop everytime i want to change tunes, from my understanding the stage3 PCM you can control the octane tune with the cruise control buttons on the steering wheel. And when it 100 octane mode the little display says it.

[Julex]

Ok well you won't be able to do that with this, but you can run 2 pcms, and if your good with electrical you can have a switch installed and hook up 2 pcms and have it switch grounds when you hit the switch. Could even splice into the cruise control button to engage the switch also. It all depends on how good you are. It's not hard, just need to be carefull and keep wires covered and clean.

[mgm1979]

ok, I'm 10 hrs into an install today, and taking a break with my 3rd drink, so I'm not reading this whole thread...here's my .02 - the Stage 3 is NOT supported by HPT, period - irregardless of what PCM it's on...the second you "Write Only" that Stage 3 tune (assuming you find a way to save it and write it somewhere else), you make THAT PCM a GMPP Stage 3 PCM - make sense?

You're SOL, for the time being, as far as "tweaking" the Stage 3 calibration goes...join the club.

[Jayson]

mgm1979 i understand that, what i want to do is write my own program using HPtuners OS that does essentially what stage 3 does. Stage 3 is nothing but a program that can be run on an PCM, why cant i write a similar program to run on the stage 2 OS? How hard would it be?

I thought about the 2 PCM idea, and i am pretty good with electrical work. But i wonder what effect it would have on the car to switch PCMs while driving? Dont you need to disconnect the batter to switch PCMs?

[Julex]

Nono you can't switch while driving, that could possible cause you to blow one maybe or it could just turn the car off. And it's not JUST a program on the PCM, it's a special PCM. That's like saying why can't you run a Supercharger boost control program on a 2000 Cavalier PCM. Sorry but it seems you must choose, stage 3 and keep your car pretty much the same, or HPT and have either 2 pcms or do what most do, and just click write for a race tune, and have almost unlimited room for customization. I don't think theres anything else you can do.

[Jayson]

you can run a supercharger boost control program on a 2000 Cavalier PCM, i did it on my Cavalier. GM just reflashes the computer, thats it.

Would it be possible to write a tune so that the PCM will continually advance timing till it gets knock and then hold at the highest timing available?