Forum,

I own a 1998 C5 Corvette with 33K miles. Since I have owned the car for about a year, I have had one major issue. I have had the original BCM swapped out for another I found online which was quoted as being "new". I had the car towed to the local Chevy dealership and they installed my new BCM for about $135. I drove the car for about two weeks with no issues. I let a friend drive it and I noticed the dash board was blinking on and off. A few days later, I went for a quick drive and I noticed the entire dash went out on me. Instead of parking it, I drove it home with no guages and parked it in the drive way. I noticed the passenger carpet was wet but I never utilized the air conditioning. I than put a tarp over the car and left it be for the winter. Anyways, last week, I bought a new battery, attempted to crank the car and got the security light and odometer reading to come back. However the car still doesn't crank. I purchased another BCM on Ebay last winter but I have a couple questions. Do you think it would be wise for me to buy a new BCM from the "stealership" and have them install it for the quoted $1300 and have them try to figure out where the leak is coming from as well. Or do you think I should plug in my used BCM? I have had the udders cleaned out last year. I am at a total loss with this car. I have always wanted a corvette but this one has made me madder than all hell. I have read many forums and have checked the bcm fuses, and have followed suit. I have even read on other forums, that it could be the grounds? I don't mind doing the work but I don't want to spend all of this money only for the car to sit on the drive way two weeks from now. Any suggestions? Thanks in advance.

 

You can't just plug in a used BCM and expect it to work. The BCM has to be programmed with the correct RPO codes for your vehicle and then it has to be paired to the PCM.

If the passenger foot well was wet you may have corrosion on the BCM connector pins and circuit board. I would disconnect the battery , remove the BCM, check and clean the contacts. If your lucky that may fix the problem. While you're working in that area you may want to clean the data star connectors. If they got wet that could also be the problem.

Bill Curlee and others have posted information on cleaning the BCM contacts and fixing leaks. You can start by reading the "Important Electrical Information" sticky in this section. Use the search function to find other related threads.

 

Taking it to a dealership would be a complete crap shoot. If you'r not willing to work on it yourself then try to find a specialty shop in the area that works on these cars every day.

The water leak could mean water is getting onto the BCM and associated wiring.

 

The first recommendation would be not to throw money at the car without knowing what is causing the problem. Unfortunately the easy way is trying to put a band-aid on the problem and unfortunately we all have been guilty of that. If you want to do it yourself, then Search and Google are your friends. You replace the original BCM but was it defective? One of the more common problems with the BCM if caused from the HVAC udders being plugged--I have had that one. Water backs up into the right foot well and you find you have a wet or damp carpet, then you experience BCM problems. As mentioned above Bill Curlee and others have posted numerous items with pictures on solving most of the problems you are talking about. The C5 Corvette has not been sold in more than 13 years and most of the tech's at a dealership who could help you are gone, retired, etc. The solutions require you to do a number of different tests to isolate the problems and it is entirely possible that some of the problems were caused when they replaced the BCM at the dealer.

 

My 2C, first figure out why your electrical issue and then resolve your leak/water mgmt. issue. As mentioned above, if your original BCM was functional, just unplug the new one and plug the new one in. Disconnect the battery and do the swap. It's an easy swap. If swapping results in no change, start diagnosing the IPC/gauge issue. The grounds are located at the base of the A Pillars on both LH and RH. Taking the trim panel off and rolling the carpet back will reveal the grounds on the hinge pillar. Hope this helps.
Cheers