I had a wire burn up on me and I'm not sure why. Got the Camaro ready to try and start up (swapped in a 2002 3800 5 speed)... hooked up the computer.. and almost immediately after I hooked the battery up the computer started to smoke. The computer actually sparked from touching the metal on the car when I moved it. By the time I realized it and got the + terminal off there was a little smoke from the engine bay. Not a lot, but still obviously concerning.

The wire was much hotter at the computer end of the wire looking at the meltedness (is that a word? ) of the wire. It was only this one wire, a 5v reference wire, and the goes straight from the computer to the ICM... making no other connections with anything. Circuit #48 on the blue plug if it really matters.

I'm just wondering if it could be the ICM's fault... or the PCM? The wiring is (should be) wired up correct. I extended the PCM harness ~2.5 feet, but I completed (solder, heat shrink and inside wire loom) every wire seperate from eachother. I'm going to get a voltmeter out and test the voltage coming from that burned wire without the ICM hooked up tonight as well as the cont. b/t all the wiring that I did just to see, but I just wanted to know if anyone had any other ideas. Could the PCM possibly being fried cause this? All of the grounds are hooked up except the tail light harness ground.

Thanks
-Bud

 

Wires burn up from excessive amp draw. I assume you mean pin 48 and that is a ground from the computer and the ICM. If the computer case sparked when touching the case to ground it sounds like the case had power going to it. I once hooked the connectors up backward on a LS1 computer and it fryed it. Are you sure they are in the computer the right way?

 

Yea, sorry, pin #48 on the blue connector ... circuit 453.

The PCM plugs were connected right, I just checked to make sure. The wire that burned up is called "low reference" by the engine controls schematics ... is this another name for a ground? I see there is a ground symbol, but it is inside the PCM... could it be possible that this ground inside the PCM is off/bad?


-Bud

 

Low reference is a ground supplied to the ICM from the computer so they have a common ground. So the High reference that sends RPM signals to the computer is valid. You must have power shorted to the wire some how. Mike

 

Good to know. I really appreciate the response.


-Bud

 

The computer and the low reference wires have ~11.9 volts going through them. I checked the 5v wires (pin 33 and 34), which I assume are supposd to be 5v, and those are 11.9 as well. I called the dealership today and they said they can only test computers in the car b/c the use the data plug. I hae the data plug b/c I swapped the dash as well.. but no way to get it to the dealership obviously.

I'm going to start going through and making sure wiring is correct, but is there somewhere I can send the computer to test it? I opened the computer up and nothing looks physically wrong with it aside from around the pin itself, which is a good start I guess.