What I don't understand is why Mods are still causing problems with GMTU. I don't know about the rest of you, since the GMTU could have been tweeked since I bought it, but. I did the TU, then added all my other toys. The GMTU clearly states that it disables the ECM's "learn-down" feature, which retards power based upon how much you uprade. When I went to HPT after all my other toys were added, my initial HP output according to HP was around 309. this was before tweeking. Another tune only gained another 15hp. According to my local tuner, the ECM's learn down was dis-engaged, and has built in paramaters for exhaust, intake, etc. Unfortunately, he couldn't isolate how or when in the ECM this took place only that it had happened. He only really had to tweak A/F levels, and timing to get the extra HP.


Now for Flashing the ECM. The GMTU is assigned to an ECM, via your VIN. SOmeone tried taking a tuned ECM out of one car and put it in their 'Balt.(my buddy Jason) would not work because the ECM was not registered to his car, and no-one would re-flash without $300.00. He eventually went with HPT and bought enough credits to do as many 'balts as he wants. We tried hooking up to my car, but HPT knows better, you actually need HHR credits. bummer same motor

 

See if u can find anyone around your area that has hptuners and have them save your tune now. If you want I can look at it for ya and also a log to go with it.

 

We actually datalogged it using HP Tuners....but he needs to download the latest version. Once we download the latest version...we'll datalog it again. Maybe I can send you the datalog and see what you think?

 

The datalog well help but if you can send me the tune you have now. I can campare my stage.1 to your stage.1 and see if something is missing. I know my stage.1 works. It's up to you it will help take the tune out of the equitation of problems.

 

PM Sent Rob

 

Stg-1 does NOT disable the learndown, per Vince.

 

I've been looking at the new GMTU with the plug and play harness kit. Does that plug and play harness eliminates the problems all you guys been having. Or would I still have issues? It seems that's the problems are with the kit that didn't come with the plug and play harness but I can't be sure. Can anyone shed some light on this? Anyone used the new harness?

 

Good question, I'm sure it will fix the top wiring problem. The bottom problem has rarely been from the connection. The 90 degree turn for the bosch sensor puts the wires out there where the movement of the engine rubs the wires against the compressor. I had both problems fixed by my dealer, I think they should patent their fix for the bottom. If I could start over I would save the 760.00 and hire Vince to tune it, and skip the stg-1 debacle. This works good on the bottom to protect the wiring that gets turned the wrong way if you add stg1

look how close the wire is to the brass stud & bolt, still. Coolant level looks about right.

 

Wow it sounds like a huge pain. Doesn't even seem worth it. Sounds like no matter who does the install I'm gonna have problems

 

Ha Ha It was, I would just skip it and hire Vince. His is twice the fun, once you feel the pull, it is over, it's addicting

"SS forever"