HELP! Intermittent Electrical Issue

[ws6speedpaul]

I have a 1999 WS6 T/A, 6-speed with 105K miles.

Just lately, I will be driving down a smooth road and the power to the radio will cut out for approx 1-2 minutes and turn itself back on. While the radio is off, I've hit the power ON button and nothing happens until it just comes back on itself. I also noticed that the power windows will also not operate during the same period of time. This has been an intermittent issue for the past several months.

Do I have a bad relay that is marginal? Help!

Thanks for any assistance that you guys/girls may provide, since this is driving me crazy.

[Jeff_in_Atl]

In your car I believe everything is controlled by the BCM. I know this sounds crazy but I have seen problems of water getting into them and causing weird problems. The units are not sealed. In the Vette they are in the floorboard and the A/C housing can drip water on them and short them. They may be behind the kick panel on the passenger side foot well where it may be getting wet from the vent under the hood.

I'm sitting here look at the picture of the BCM in the parts manual and I can not tell from the crappy picture where it is.

Oh and in my Vette I put the BCM in a plastic zip lock bag unzipped with the opening facing kind of downward. So if water drips on it, it won't get the electronics wet.

[ws6speedpaul]

Thanks for your feedback.

Thinking out loud...this issue does not seem to be related to rain, since I have not been caught in the rain nor has the A/C been on for the past 6-weeks. However, that also does not rule out water damage caused some time ago that is now manifesting itself into the issues that I am currently seeing.

Dumb question, but if root cause could be traced back to the BCM, wouldn't I see more issue?

Anyone's else?

Thanks!

[Jeff_in_Atl]

Not necessarily. It depends on what got wet (if that is what it is). But I bet you a dollar if you took to a dealership they would say it has to be replaced and that would be about $1000. The BCM is the same for all models but it has to be programmed with the options of what your car has. So it’s the BCM plus programming plus installation. The BCM is the only thing I can think of where those 2 systems are related.

[Injuneer]

Based on posts I've seen on other forums, the body control modules are plagued by poor soldering and loose contacts. What you describe isn't an unusal problem, not necessarily related to water. There's an ongoing thread on CamaroZ28.com "General 1967-2000 F-Body Tech" forum regarding problems with the BCM.

[ws6speedpaul]

Thanks guys...all this information makes great sense and has given me an excellent starting point to trace my issues.

Have a great weekend!

[Joe 1320]

I'm going to chime in and agree that it sounds like the BCM.

[Christopherrr]

I have the same issues - stealership told me the BCM must be replaced. $850.00 + $95 to flash it. Hmmm...I told him no thanks. I'll live with the cut outs for now...

So...until now, I've been more busy trying to stop an exhuast leak. Next, it's the BCM.

[aldaran]

I had the same issue. Had no choice but to take it to the dealer. The BCM had to be replaced. The BCM was $300 plus $89 for Labor that included reprogramming it and the keyless remotes as well. Mine had gotten to the point where it would do it everyday at least twice a day.

[FTA1995]

well ya shouldn't ned new remotes...
You can program those yourself, look at shbox.com hes got some great how-to's and manuals on there.

One thing you MIGHT be able to do for now is this,
locate the ignition power link in the fusebox.
run a 24 gauge wire from that terminal to the IGN wire on the radio, prestor, shouldn't have anymore radio problems. This would of course be a temporary fix, I'm not 100% sure if the BCM cuts out the other components.

however, If you need a new BCM, you need a new BCM.
See if theres a way to flash BCM trouble codes on yours. I think there is a way to do it on mine(I DON'T have a BCM on my 95) where it flashes the "security" lamp on the dash.

by no means should it be 900$ for all that labor.
the flash should only contain VATS info like the pellet code for the key, and stuff of that matter. You might even be able to get away with a junkyard BCM and get the VATS disabled by someone with a programmer.

Just an idea.
I hope you don't absolutely have to go to a dealer.
Thats just too expensive.

[aldaran]

See if theres a way to flash BCM trouble codes on yours. I think there is a way to do it on mine(I DON'T have a BCM on my 95) where it flashes the "security" lamp on the dash.

I do have the steps to get the BCM trouble codes. When I ran mine, it had 1 current code, and a quite a bit of history. I believe there are about 10 possible codes or less and mine had almost all of them. Most of them indicated a short to ground, but the items shorting worked perfectly. That's what led me to believe it was the BCM. Let me know if you want the steps.

[FTA1995]

Most of them indicated a short to ground, but the items shorting worked perfectly.

The items that were indicated shorted still worked?

or...

If that's the case its probably the solder points going to hell, and you'll need a new BCM.

I'm guessing the short to ground(s) were involving the radio anti theft and RAP module?

Just a guess.

[aldaran]

The items that were indicated shorted still worked?

or...

If that's the case its probably the solder points going to hell, and you'll need a new BCM.

I'm guessing the short to ground(s) were involving the radio anti theft and RAP module?

Just a guess.

RAP module was shorted to ground was one. Courtesy Lamps shorted to ground was another. Security indicator was another, but didn't say shorted. I don't remember the rest, but I will check my notes tomorrow and post all trouble codes for the BCM. It listed all these items, but the courtesy lamps worked fine, so did the others.

[FTA1995]

It's probably the solder points on the inside of the BCM then.
If it were ME, I'd pry the box open to try and fix it anyway, but you'll probably stuck with a dealer for help.

[aldaran]

Here are the possible codes a BCM can store. I did have the dealer replace my BCM and all is well again.

DTC 12 Diagnostic System Check
DTC 21/31 Courtesy Lamps Feed Shorted to Ground
DTC 22/32 Courtesy Lamps Return Shorted to Battery
DTC 23/33 RAP Feed Shorted to Ground or Battery
DTC 24/34 Seatbelt Indicator Shorted to Ground or Battery
DTC 25/35 Security Indicator Status
DTC 41 Last Message Received Valid
DTC 42 Last Message Received Invalid
DTC 43 Last Message Received with Sumcheck Error
DTC 44 Last Message Received with Enption Error
DTC 45 Receiver Processing in 20 Second Lockout
DTC 55 Begin Configuration Display

As you can see, there can be several DTC's. DTC's starting with a 2 are active while those starting with 3 are history codes. The codes are flashed through the Security Indicator Lamp. The ones underlined above are the codes my BCM had.