Door lock / bcm problem
Door lock / bcm problem I have a 2001 trans am WS6 with a factory alarm system. The driver side door lock does not work with the door switch or keyless remote. Sometimes very rarely it will work. I took it to the dealer because the car was still under warranty and they said the door actuator was bad. They replaced the actuator and it still didn't work. The tech eventually determined that the control module (aka "bcm") was bad. I did a little reading on this forum and some people with door lock problems have replaced the door lock relays in the bcm and that fixed there problem. Is this hard to do? Is it reasonable to assume that this would fix my problem? I also have the security light issue from time to time. I cleaned the ignition switch and my key and it seems to not occure as often. Does the bcm need to be replaced? What should I do?
Okay so I pulled the bcm yesterday and reheated/ added soder to the area that looks like a T. I reinstalled it and the security light issue has yet to pop up. The door lock problem is still there. When I was looking at the bcm I saw four black boxes that look like relays. Are these the door lock relays? Would replacing them fix my door lock problem? Or should I just buy a new bcm?
I could really use some helpful advice.
I could really use some helpful advice.
Joined: Nov 2003
Posts: 11,328
Likes: 345
From: Jacksonville, FL (originally from Toronto Canada)
First, the solder fix is very specifically for the RAP (Retained Accessory Power) circuit in the BCM and has nothing to do with VATS (your security light) or door locks.
Second, if you are having problems using the remote to lock the doors - the passenger door locks but the driver door doesn't - you can rule out the BCM altogether. Both door locks work off the same circuit (in fact, the same output wire) at the BCM. Also, both lock and unlock from the door switches work through the same input wires so, again, if one works but the other doesn't then it's not the BCM. The only scenario where the BCM could be the cause of a driver-door-only lock problem would be if the driver's side locks but doesn't unlock using the remote or inside switch.
Second, if you are having problems using the remote to lock the doors - the passenger door locks but the driver door doesn't - you can rule out the BCM altogether. Both door locks work off the same circuit (in fact, the same output wire) at the BCM. Also, both lock and unlock from the door switches work through the same input wires so, again, if one works but the other doesn't then it's not the BCM. The only scenario where the BCM could be the cause of a driver-door-only lock problem would be if the driver's side locks but doesn't unlock using the remote or inside switch.
Okay, what should I check to figure out these issues. The security light will come on at random times when I try to start the car. At that point the starter will not engage, but I do get power. I have to wait a few minutes for the security light to go off before it will start. From what I have read it seems that the VATS system is not correctly reading the correct resistance range for my key and shuts down the power to the starter and fuel pump as a type of thief deterrent system. You are saying that this problem is not at all tied into my BCM? I have cleaned the key and the contacts in the ignition cylinder. I suspect that the problem could be the ignition key cylinder, because the key fits loosely inside it and when the car is running the key can be easily removed from the ignition cylinder. Is this a reasonable assessment? Now as far as the driver side door lock problem goes I am kind of stumped. It use to work from time to time when I would hit the key fob or door lock switch inside the car. That was when I had the dealer look at it and they said the door lock actuator tested fine with a voltmeter and they determined the BCM to be the problem. Now the driver side door lock does not work at all not even from time to time.
Where should I go from here?
Where should I go from here?
Joined: Nov 2003
Posts: 11,328
Likes: 345
From: Jacksonville, FL (originally from Toronto Canada)
The VATS system depends on getting a good reading of the resistance of the pellet in the ignition key. If your key is loose within the ignition cylinder, I would say that is a likely candidate for the cause of bad connections causing VATS to prevent the car from starting. You can either replace the ignition cylinder (recommended) or bypass VATS using resistors in the connector at the base of the steering column.
As far as the door locks, I suspect that the actuator is mechanically gummed up. It could test fine electrically but not actually move to lock and unlock the door.
As far as the door locks, I suspect that the actuator is mechanically gummed up. It could test fine electrically but not actually move to lock and unlock the door.
Thanks for the speedy reply. I agree that the ignition cylinder is probably the reason for the VATS issue. The door actuator is what I suspect as well but I wasn't sure. Two heads are always better than one. I just wish the dealer would of just replaced it when I had it in there. Hopefully I can get this take care of soon. By the way, how easy is it to replace the ignition cylinder?
Thanks again.
Thanks again.
Joined: Nov 2003
Posts: 11,328
Likes: 345
From: Jacksonville, FL (originally from Toronto Canada)
It's not particularly difficult but it takes some time. You have to remove the air bag and steering wheel, the air bag coil, the lock retaining screw, wiring harness retaining clip, then pull the harness up through the column and remove the cylinder. The toughest part is fishing the harness from the new cylinder back down through the column.
Trending Topics
Okay well I found a few write-ups on doing this. I'm gonna pick up an ignition cylinder from Oreilly today. Then have the key cut and programmed Tuesday and hopefully have it done by the end of that day. Hopefully all will go smoothly.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo Ignition cylinder install went very smooth. Tying a string to the old ignition cylinder harness helped when it came to running the new harness down the column. It's been over two weeks since I did the install and the problem has not returned. I think it's safe to say that the problem is fixed. Thanks again for all the help.
