Does anyone have one of these? I've got a harness from a bonneville for a 3800. It was the only 2003 3800 engine in the junkyard and I needed the 2003 stuff to drive the 2004 Tranny I've got. In tracing wires to the pcm it appears its wired identical (also the PCM has the same service part number) but I'm finding most of the wire colors are different than a 2003 grand prix 3800 PCM.

An actual pinout for a 2003 bonneville would be fantastic if anyone can help

Is this what you are looking for ? Here

thats what ive been using and while sensors seem to line up right colors do not. thats making me nervious...

I have no experience with the wiring yet but are you 100% positive it's a 2003 ? Maybe check the other pin outs from the same site. At least that's what I would try. Good luck

quote Originally posted by Adjustso3: I have no experience with the wiring yet but are you 100% positive it's a 2003 ? Maybe check the other pin outs from the same site. At least that's what I would try. Good luck

Cant say I'm 100% positive. I just know the junkyard labeled it a 2003. That would certainly suck to find out otherwise. Guess I'll find out for sure when HPTuners gets hooked up to it.

so each pin on each connector is labeled, hook up an ohm meter to the pin on the PCM and the pin on the sensor and check resistance, if it's almost 0, then it's wired right.

If most of the wires are colored wrong, there is something wrong.

GM wasn't consistent on the colors of the EGR wiring. The MAP might have a Black or an Orange/Black wire. Sometimes GM used a Pink/Black for the power to the MAF. Sometimes GM used Black/White where a Black is expected.

Those are most of the color inconsistencies on the 3800 harnesses.