Expensive Repair in Process

After two dead batteries on my 2001 Coupe it was taken to the dealer on a flat bed truck. The first report is BCM (Body Control Module) is drawing 4 amp and that is what is killing the batteries. The big unknown at the dealership is to find and understand what circuit is shorted. Just replacing the expensive (heard $1,000) BCM may not fix the problem. They are trying to find the bad circuit and this could be as expensive as the BCM.

Dad..... any experience with BCM current draw issues?

Reply to
aRKay
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Yes, all bad. Happened to me with the '98, was only $800 but that included the flat bed, a week rental car, and it was 10 years ago and

200 miles from home. What codes did it throw? Short was in the unit its self. Rebuilt BCMs go for $165 and are as good as or better than new.
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Yes, I've dealt with them with good results.
Reply to
Dad

How to Pull Codes:

  1. Turn your key to the "ON" position, but do not start the engine.
  2. Clear any present messages by pressing the RESET button.
  3. Hold the OPTIONS button down, and press the FUEL button 4 times. (This will get you into the "codes" section of the DIC.
  4. The computer will automatically display all the codes your car has created. It will cycle through each code every 3 seconds. (Have a pen and paper handy to write down the codes)

Note: Any code that ends in an "H" is a history code (something that has occurred in the past, but is not reporting as an error currently.)

  1. Once the computer has finished going through all of its codes, press RESET to enter Manual Configuration mode. It should start with a module and show "NO CODES" or "# Codes."
  2. To optionally reset codes once in manual mode, press and hold RESET until is displays "NO CODES."
  3. Press OPTIONS to go into the next module (ie, from PCM, or Powertrain Control Module, to TCS, or Traction Control System.)
  4. Repeat Step 6 until you have reset all the codes in all the computer modules.

Note: Only reset the codes if you want to- it is not necessary to reset them every time you pull the codes.

  1. When finished, simply take your key out of the ignition.
Reply to
Dad

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for the C5

Reply to
Dad

I am wondering if this procedure to display codes also works for current C6 models?

Reply to
Smarty

Nope, you need a reader or a program to read them as far as I know, things do change though so don't just take my word for it. I invested in a OBDII program that reads and cancels most OBDII codes except ABS.

Reply to
Dad

Thanks!

Reply to
Smarty

Dad,

I went to the web page listed and they talk about ECU's

Is that the same thing?

aRKay

Reply to
aRKay

I called and the guy was very helpful. Yes they do BCM's and the price you mentioned is correct. Interesting they have to repair your module because so the security code does not have to be re-flashed. As I described the problem the guy did not think it was BCM issue. Like the dealership he suspects a short somewhere on the hot side of the BCM.

I am stuck since the car is at the dealership and customers cannot talk to techs. I have to deal with the service writer who relays what the techs tell him. Catch-22!

Stay tuned for the outcome

Reply to
aRKay

You can't talk to the tech??? WTF!!!

I'd have a truck there in a heartbeat to yank it out of there.

Reply to
Roy

Can you tell me if the 12-disc CD player in hatch is one of the items controlled by the BCM? The reason for asking is I have a rebuilt

12-disc player and I know power is hot to the unit even with the key OFF. If I sound like I a grabbing at straws.... I am. HiHi
Reply to
aRKay

Why is the player hot with the key off, it should time out like the rest of the accessories?

Hard to say, with over 2,000 codes just to run the engine I have no desire to check out all the "U", "C", "P", and "B" codes to find one by a word search. You need the failure code to start tracking a problem.

Reply to
Dad

On Monday the dealership called saying it could be the $1,000 BCM (Body Control Module) because the vehicle was drawing 6 amps with the key OFF. The tech was trying to find the short or whatever that killed two batteries. He was having to do it the old fashion way ­ one circuit at a time. The service writer called back at the end of the day saying the new battery was okay that it charged fine and the tech found the interior lamp ON so he turned it OFF. The excessive current draw stopped but he wanted to let it sleep over night in his stall and check it in the morning. They called Tuesday and I have the car back. For only $114 we went from Intensive Care to Release.

I have no idea how the interior lamps got turned ON but it was dying on me during the day and I probably never noticed the lamps staying on. The lamps turn ON when you open the door and they stay ON when you close it for about 30 seconds. The same set of lamps double as Map lights with two ON/OFF buttons in the mirror. I do not remember turning on a map light but may have done by accident the last time I washed the car and cleaned the mirror. The last wash was the morning before all this crap started.

Dodged an expensive bullet on this one. The real test will be to see if it starts after spending the night in our garage

Reply to
aRKay

I forgot about that, you may not have turned it on at the mirror. It can be done by your left knee on the dash. Check it out.

Strange they got 4 amps one time and 6 this time.

Reply to
Dad

My C4 was killing batteries. It turned out to be the interior lights. In that model there was a little metal tang next to the headlight switch to turn inside lights on. I guess when turning headlights off I kept hitting it. Went from a new battery every year to one that has now lasted four years.

G
Reply to
George Csahanin

I called and asked the service writer about the 4 vs 6 amps. He wrote down 4 from his discussion with the tech on first test but the tech notes on the invoice for what he found said 6.25 amps. The 6.25 may be after they installed the recharged battery.

On the same follow up call I asked about the map light and he said it was the pot on the dash dimmer lights. I just tried it and when you roll it just past high, the interior lights come on. I could have done that cleaning the dash. I tend to forget about the dash dimmer switch

Reply to
aRKay

I found out about the changer wire being hot when I called the place that sells or rebuilds the 12 disc changers. As a test he had me pull the connector to do a reset. It is hot all the time.

Reply to
aRKay

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