Jesus Freak

Hey guys, I have an ls376/480 and the GMPP controller kit that goes with it. The GM part number for the ECU is 19201790.

I have a PLX gauge that reads OBDll, when I read the parameters, at idle it says my tps is 21%, rpm is 1000, and it says I'm moving 18 mph while sitting still. Do I have some issues, or is the gauge not reading correctly?

Jesus Freak

Will HP tuners credits unlock/work with my ECU?

BLK02WS6

iTrader: (2)

I remember hearing at one time that the GMPP controllers were locked down and couldn't be tuned... don't know for sure if that is true or not or if they still are... might try to find someone near you with either EFILive or HPtuners and see if they can get into it - a shop with an unlimited cable shoule be able to read/write to it without using credits or needing a license...

foff667

iTrader: (2)

We added the GMPP support a couple of years ago to our software. Contact support for the newest software update and you shouldn't have an issue tuning it.

Jesus Freak

Thanks guys. I'll be ordering HP tuners here soon. I just didn't want to dish $500-$650 on software that won't work. I'm having my car professionally dyno tuned, but wanted to have my own software for scanning and minor tweaks.

Jesus Freak

So I tested my tps with a multimeter and at idle it puts out .9v and WOT it is 4.2v, which corresponds to (roughly) 18% at idle and 88% at WOT. Is this normal or do I need to "re-learn" the tps?

Also, I have my tci EzTcu pulling a tps signal from the harness bulkhead and I can depress the accelerator 10% before the TCU even starts picking up a signal. That related or another issue?

Jesus Freak

Checked voltage at the bulkhead and got 1.27 volts at idle position. That's about .3-.4 volts higher than at the pedal. So where am I picking up voltage? Should I tap the TCU tps wire directly to the pedal?

Jesus Freak

Got it figured. For some reason the output on the bulkhead doesn't work as it should, but wired it directly to the pedal and all is good