every know and then my windows wont go up or down, the problem didnt start till some punk shot out my d side window. could that have been a coincidence or do i have this problem?

 

Does your radio shut off when it happens? If so, it was a coincidence and your BCM took a **** on life.

If it is just a power window failure, maybe glass cut up wiring and is causing intermittent shorts.. who knows. Tear the door apart and find out.

 

No the radio is fine, looks like i get to take my door apart. this is still good info. who knows i may end up with this problem somtime in the future and now will be able to fix it. thanks

 

Hello everyone,

This is my first post, but I've been a long time lurker and a member of other ls1 forums for years. I have a 2000 Trans Am that I believe has this problem and I would like to try to fix it asap.

The problem is I cannot seem to get the BCM out of the car (if I'm looking at the proper black box). I don't know how the rest of you access the area but what I did was simply push the tabs on the glove compartment box so it falls down and I can see behind the glove compartment. In the bottom right hand corner is a black box I believe to contain the BCM. It has 2 tabs on the right and left sides that seem to snap out. The problem is I can only get to the one on the left, as the right side one is blocked by part of the dash and I can't get around to pull on the clip.

From others posts it sounds like you can remove the box without unsnapping? I don't see how you can get the box out as the top of the box seems to be wedged into the dash.

I know it sounds sad, but could someone please give me a bit more specific advice on how to get this thing out (and to make sure I'm actually looking at the BCM)?

Thanks in advance, I've been dealing with this phantom problem for almost 2 years now, always seems to become apparent when it gets around summertime, and goes away when it gets colder (probably the solder joints expanding and causing issues).

justin

 

I recall when I took the BCM out that I got it to come out in an upward direction with considerable force. I did not break the clips in the process and even if you do, I wouldn't be too concerned. Be patient; you'll get it out.

 

Hmm, in order to get it to come out in an upward fashion I would have to remove the dash. Right now directly above the box is the airbag.

I'm trying to figure out whether I'm going about this wrong, by just accessing the spot through the glove compartment. Can someone tell me what screws or pieces of the dash they had to remove?

Thanks again for all the help.

 

So this post is for anyone like me that had no clue HOW to get to the BCM. All the posts I've read on this site and others either don't mention accessing the BCM or are vague about what needs to be removed to get to it. I finally was able to do it today and took some pictures to help those that want a little picture advice.


Here's the tools I used for the job (not counting the 25w soldering iron I picked up at Home depot):


The easiest way to know what the BCM looks like (plastic holder that encases the BCM that is) is to look at it through the glove compartment. Open the glove box and push on either side near the top of the hinge to let the tabs push inward so the box swings all the way down. You can now easily see the black plastic housing that contains the BCM. I had originally thought I could access it through here but no dice.


Shot of the BCM housing as seen through the glove compartment. It's really frustrating since almost the whole damn thing is staring right at you...


You need to remove this piece that goes along the right side of the base of the door on the inside. Surprising there is nothing holding it to the car where your feet would go, it's simply held in place with 5 screws along the floor that are easy to remove. 4 of the 5 are very easy, the last one required me to move the passenger seat all the way forward so I could get a screwdriver on the screw. If you had a really short (1") 90 degree angle hand phillips head you could also do it this way.


This was the bane of my first 2 attempts at accessing the BCM. This plastic push holder is a bitch to remove. There are 2 of them directly below the glove compartment and they are all that is holding up the plastic cover hiding all the wires and the BCM housing. It wasn't until after I had it out I realized it is simply a friction holder and not a plastic rivet or something that had to be released from above. The easiest way I found was to use the t-top key or some other thick strong piece of metal to use as a wedge while my fingers pulled down. I'm sure now you could just get a pair of pliers or something and just pull. If you look at the push holder there is nothing that can break, so just pull down hard and it will come out.


After lowering the plastic cover you still have one thing to remove to get the BCM out. This thick black plastic tubing holds a bunch of wiring and is blocking the BCM from being pulled out. There are 2 clips that need to be released so you can pull the wiring down and out of the way. The easiest way I found was to use a razor blade to pull up on the tab. It takes a little work but once you figure out how to release it the second one goes very easily.


Here's the tubing pulled down and out of the way.


Finally you have access to the BCM housing. This picture was taking looking straight on from the bottom of the car. There are 2 clips on either side of the housing towards the front of the car. They pry off the back with a bit of force. The left one is easy to get too but the right one is a PITA since part of the dash is somewhat blocking it. The problem is when you pry one side off, then go to do the other, if you don't keep the 1st clip away from the housing it snaps back on when you go to do the 2nd side. What I had to do was pry off the left side, slide my hand in the gap created between the BCM housing and the clips holding it in place, and then pry off the right side. It is not easy, and you'll have to try a couple positions to get that right clip off.


Once the clips are off, you pull the BCM straight down. Again this takes quite a bit of force but don't worry. There are no wires or things to be damaged that you cannot see. Only the wires seen in picture #8 which were at the bottom. Now that you have the BCM out you have 2 choices. You can remove the 3 connectors and solder somewhere else, or like me (since I could not find out how the hell to get the 3 connectors off) just pry open the BCM housing (again I used the razor blade on the 2 little tabs, then it simply opens up like a clam to expose the circuit board).




So that's it. Now you can use the pictures in the original post to finish the job. I looked closely at my board and like the others the bottom solder joint was spidered. Now, I have not soldered since 9th grade electronics class and so was a bit worried but if you work cautiously, it should be easy enough to reheat the joints. I did put a little solder on each joint to help the reheat as the contacts coming up are pretty tall and it's tough to reheat the existing solder without having some liquid solder on the tip of the gun to help the melting.

Once done soldering, turn the car on and make sure it starts. If so, consider it a possible success. It's getting colder now and so I won't really know until it's spring or we get a sudden hot weather spell (as that's when my radio/window issues occur). Then just go in reverse putting the parts back together. First the BCM (this took a long time because it takes a lot of force and the tabs are a PITA, for reference look through the glove compartment to make sure you have it pushed up high enough, I thought I was until I saw there was still another 1/2" or so), then the black tube holding the wires, then the bottom piece with the push screws, and finally the plastic piece along the door.

Hope this helps someone!

 

Thanks for all the info and pics. I was having the same problem with windows and radio and took out the BCM, re-soldered the connections and works perfectly. Also, I also believe this is a common problem. In my search for the fix I ran across many, many posts about the same issue.

Thanks Again!
Travis

 

Glad I could be of some help. And like you I came across many posts about the issue, but there was never a description of how to get to the BCM, just what you do once you get to it!

 

What is the green arrow pointing to?

 

I got the two panels off and am still strugling to get connections loose or
remove bcm. I noticed a spark at one of the connections. Would it help
if I disconnected the battery?

 

ok I got the bcm out I just used brute force on the left side catch and pried it out.
Reheated solder joints then car wouldn't start then I disconnected battery and reconneted it and it started. I got a traction control light off for a little while then
that went out. The radio and windows are working right now so maybe it worked I'll
update later.

 

I see I'm a bit late to respond, but for others, the green arrow was simply showing the BCM in relation to the opening. I also added a pic (last one) I forgot I had taken with the circuit board showing as it was still connected to the car. Like you I spent a good 10minutes playing around with the connectors before deciding to solder with the board still connected. I didn't even disconnect the battery....

 

Dumb question about this. My car's radio and windows work just fine (well, assuming the window motor doesn't burn out again lol) but every so often the power locks fail. Like, I push the switch or hit the lock button on the keyfob and you can tell it registered because it arms the alarm, and there is a click in the dash, but the doors don't actually lock. If I punch it a few times when it does that it'll finally lock. Very random though and it has been fine for the past few weeks.

Could the BCM be the culprit of this? The click sound in the dash sounds like it comes from the passenger side.

 

SparkyJJO, I can't answer your question, sorry.

I wanted to post again to update after having done the mod 2 weeks ago. Fortunately we've had an unusually warm October and so the car has gotten up into the 90's on several days when set in the sun without the sun visor up. This is when my BCM would sporadically trip the radio/window/etc. to stop working. In the 2 weeks since doing this mod I have not had it turn off ONCE! I'm going to call this a success and want to thank the OP once again for this great fix.

 

THis was a great success, all pictures helped greatly, and was able to get my window, radio dilema solved without a pricey repair. Thanks!!!!

 

Knowing as I have that stupid issue. Great info & write up! I'll have to give that a try soon!

 

Thanks for all of the pics and information! I just now finished re-soldering, and everything worked fine in the 5min test drive.

My only question is...why doesn't my radio stay on once i turn the car off(before I open a door)? It's only stayed on about 10-15 times in the last year

 

7Enigma thanks for the fantastic write up on this , we did a friends 97 Camaro, the wiring harness was a bit different it doesn't drop as far, but otherwise everything else was the same including the issue with the cracked solder joints.

 

Funny! A friend of mine was having the same problem with her '96 Z a few years ago. She replaced the BCM and problem solved. If we had know about cracked solder she could have save a couple hundred dollars by not buying a compter. Good info.