PCM Diagnostics & Tuning - Disconnect this wire, car won't start...




DustinSS
08-23-2006, 02:47 AM
This is a repost since it didn't do any good in stereo/electronics..

Ok here goes. I have noticed a black wire that is spliced into a pink wire under my fuse box in the engine compartment. It's the fuse box with the AC comp, fuel pump, IGN, etc. I can't find where the black wire goes to once it crosses into the firewall, but I've looked under the dash and behind the radio and no go. So, I decided to see what happened when I disconnected the mysterious wire and found out that the car turns over, but won't start. If you disconnect the wire while the engine is running, it immediately shuts off. With the wire disconnected, everything still works like the radio and dash lights and windows, and fuel pump can be heard, etc. you just can't get the motor to "fire". Could this be the old remains of an after-market remote starter? I haven't thought to check the security light while I do this tho..

Any ideas on what this could be, why it is there, and should I just leave it there? BTW this is Dustin's brother and a 2002 Trans Am not his 99 camaro.

THANKS

UPDATE: A shop here in town said there were some problems with the computers in 02 not having enough power or grounding out or something and that this is probably why that wire is there. Is that BS? Also, after reading more on here I think it might be a VATS bypass, but not sure if the bypass includes wiring an IGN to something else. It seems like if the black wire were powering the the computer they took the long way around to get to it. Any takers??


joecar
08-23-2006, 03:26 AM
Which fuse does it go to (what is the fuse labeled...?)...?

LS1Cobra
08-23-2006, 03:53 PM
Do you get a "service column lock" message after you pull this wire? I think it's the column lock bypass circuit


DustinSS
08-23-2006, 05:31 PM
The fuse is either the PCM Bat or ABS sol (i'm pretty sure by looking that it's the ABS sol, but the PCM Bat is right below it and I don't have time right now to pull everything out again). There is another pink wire that has been cut and put back together as well, almost like they tried something there but it didn't work. I don't recall seeing anything unsual on the dash after disconnecting the wire, just the motor dies QUICK. Would the "service column lock" be a code thrown that I need a computer for or just a light on the dash? I'm seriously thinking about letting an expert examine the entire wiring harness because the fuse panel inside on the driver's side looks like it has been out and put back in, so there is no telling what is going on behind there that I can't see. Also, under the dash there are a couple of fat pink wires and a fat yellow wire that have little holes in them like they have had one of those testers that pokes a hole hooked up to them. If I just would have pulled the little cover off before buying it (the car), I probably wouldn't have bought the car because this all seems too weird. It makes me mad that I paid $19,000 for this and it's supposed to be PERFECT! I guess the first tip-off should have been the after-market radio. :bang:

TIA!

LS1Cobra
08-24-2006, 08:02 AM
Most of the PNK wires are ignition feed wires. On the C5 you get a message display on the instrument panel that tells you "service column lock" if the BCM confuses which state the your ignition and key are in. I don't know how this being done with the Fbody cars. If you read the sticky on top about the column lock problems you would assume this would be the column lock bypass module that the previous owner installed. If everything works don't loose sleep over it. Just keep in mind that if for some reasons one day you can't start your car then remember to check the power to that black wire. Good luck
Vinh

DustinSS
08-24-2006, 05:15 PM
Thanks for the advice and yeah I basically told myself "just splice the wire the RIGHT way and leave it alone, if it works it works and obviously I need this wire so just get over it." So I did a good splice and thought I was golden..

Today I pull up at the gas station to get some Petro and I turn the key off and pull it out. Well, the engine decides it doesn't want to stop!! So there I am with the key in my hand and the motor still running!?! (one of the worst feelings ive ever had :confused: ) I pop the hood, tap around on some fuses/relays and it turns off. I think the relay I tapped when it finally turned off was the IGN relay. After pumping gas I started it back up and went home and it turned off fine with no problems. These intermittent problems are seriously pissing me off to no end and what should be a reliable car can't be trusted to start and/or turnoff when you want it to. I know this is NOT a GM problem at all, it's a "lets just rig it up" problem. Auto Zone is getting to know my name and the relay I seem to keep having to buy over and over. The GM dealer here said the panel was shorting out, so if you combine the shorting panel and electrical taped splices, well there you go.. this car and purchase make me want to :barf: The moral of the story is before you buy a car take all of the fuse panels out and check the wiring, too. I'm calling the used car dealership I bought it from :engarde: