Possible PCM or BCM prob - advice needed
Thread Starter
Burning Brakes
Joined: Jul 2002
Posts: 1,185
Likes: 2
From: Indianapolis IN
Possible PCM or BCM prob - advice needed
I am having intermittant problems with several warning lights coming on on my 99 coupe. When problem occurs, the check gauges, ABS light and trac control lights (and probably a few more) come on, I get an error of low fuel and reduced engine power. Some gauges also appear to be non-funstional when this occurs as fuel reads empty, temp is pegged to 260 and oil pressure shows 0. Car runs fine when all this occurs.
Oh - also the radio stops working sometimes when all this occurs.
I am speculating that I have a faulty computer unit. Would this be BCM or PCM (i am pretty sure this would not be ECM)? I am considering attempting to purchase a used computer unit an swap it out. Any thoughts on which unit I would need or any issues with swapping out to a used unit from another vehicle?
Oh - also the radio stops working sometimes when all this occurs.
I am speculating that I have a faulty computer unit. Would this be BCM or PCM (i am pretty sure this would not be ECM)? I am considering attempting to purchase a used computer unit an swap it out. Any thoughts on which unit I would need or any issues with swapping out to a used unit from another vehicle?
Race Director
Joined: Aug 1999
Posts: 17,541
Likes: 2
From: Manhattan, KS Missing SoCal since 2005
Could be the BCM - have you checked for moisture in the passenger footwell? I had a BCM on my old 2000 coupe go bad due to A/C condensation because of a plugged drain on the firewall. Symptoms were pretty much as you describe.
Race Director
Joined: Nov 2001
Posts: 18,682
Likes: 4
St. Jude Donor '05-'06-'07-'08-'09-'10-'11-'12
Race Director
Joined: Nov 2001
Posts: 18,682
Likes: 4
St. Jude Donor '05-'06-'07-'08-'09-'10-'11-'12
I was in contact with the guy who posted this thread. He had a corroded power connectors underneath the driver's seat. Mine acted up the same way and my problem was corroded negative battery terminal bolt. I however, did service all the ground points just as a precaution. It took me several weeks to figure out what actually the problem was. Dealership wanted me to order bunch of different parts totaling up to $1300.00 I ended up needing non of those. I never did order anything except for passenger window contol module and passenger window switch. I got those from Gene's Karshop. I ended up not using them either as the problem was corroded battery terminal bolt. Hope this helps 
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
I had a 98 with simular issues. Here are some things that you need to do BEFORE you spend large sums of money and get NO WHERE!
As stated previously; Check the passengers foot well under the toe board for any signs of water! VERY GOOD ADVICE!
Check the carpet, jute underlayment under the carpet and the BCM for any signs of moisture. If you find any, let me know and I will tell you how to solve that problem!
Next, my 98 was the car from HELL! I had some serious electrical issues that caused me to be stranded more times than I wish to remember. Long story short, I had corroded chassis grounds and the link below details how to solve that issue. I cleaned the grounds and just about ALL problems were fixed.
http://forums.corvetteforum.com/show...al+information
Next, remove your battery cables and clean the terminals and reinstall the terminals. Use the proper torque on the fasteners.
Read all of the codes in your DIC. After you read and copy them down, clear ALL of them and then post the results for us to review what is hapening.
PLEASE let me know if I can answer any questions to make the chassis ground connector cleaning any clearer.
Bill Curlee
As stated previously; Check the passengers foot well under the toe board for any signs of water! VERY GOOD ADVICE!
Check the carpet, jute underlayment under the carpet and the BCM for any signs of moisture. If you find any, let me know and I will tell you how to solve that problem!
Next, my 98 was the car from HELL! I had some serious electrical issues that caused me to be stranded more times than I wish to remember. Long story short, I had corroded chassis grounds and the link below details how to solve that issue. I cleaned the grounds and just about ALL problems were fixed.
http://forums.corvetteforum.com/show...al+information
Next, remove your battery cables and clean the terminals and reinstall the terminals. Use the proper torque on the fasteners.
Read all of the codes in your DIC. After you read and copy them down, clear ALL of them and then post the results for us to review what is hapening.
PLEASE let me know if I can answer any questions to make the chassis ground connector cleaning any clearer.
Bill Curlee
