2002 Power Door Locks going crazy in cold

[fenross]

I have a 2002 Venture.

A few weeks ago, the van sat out overnight in <10 degree F weather. The locks started continuously unlocking every 20 seconds or so. I pulled the battery from my remote, just to be sure that wasn't it, and it didn't stop the problem. I pulled the fuse for the locks to be sure the battery wouldn't drain overnight, and flipped the switch on the overhead lights.

The next day, after driving it a while, I replaced the fuse and the problem was no longer happening.

Then we had a cold spell with temps below 0 F. The locks started acting up again. When I had the door open, it would give me a warning tone, like when you hit the lock button with the door open, but the locks were mostly trying to unlock, as far as I could tell. Even with the dask fuse for the power locks pulled, there was still a clicking behind the dash and the warning tone. I pulled a main fuse from under the hood to prevent battery drain. The next day, after replacing the fuse it was still happening, so I made an appointment with the dealer shop and took it in. By the time I got there, it had stopped happening.

The dealer pulled the switches and inspected them for shorts. They said that was the most common problem with the locks acting up - the switches getting wet from rain or some other cause. They didn't find anything, and of course the problems wasn't happening for them.

It happened again this past weekend when the van was left outside overnight. No warning tone, but the continuous clicking of some mechanism behind the dash even when the locks fuse was pulled. I took it in to the dealer, left it overnight so they could check it first thing in the morning. Of course, we've had some warmer weather, so the van didn't get as cold, I guess. They reported that nothing was going wrong for them.

I left it out again last night just to see, and when I got up this AM the overhead lights were on, which I assume is from the locks cycling again. They don't seem to be going as fast as they were last weekend.

I'm trying to get this fixed under the extended warranty, so I think they are hesitant to just start replacing things. It might get cold again next week, so I'm going to try leaving it at the dealer's overnight again then... but if anyone has had this experience and could point us in some direction, I would really appreciate it.

Thanks!

[ponchonutty]

Good luck. GM vehicles are littered with electrical problems. I own a remote start shop and even I don't know where to start on your vehicle.

[stomana]

never buy GM car.

[grape8pe]

I'm having the same probem as you with my 2001 Venture LS. Have you found the solution to your problem yet?

[gmtech79]

Either your driver or passenger door unlock circuits are shorting to ground or your BCM is bad. When the BCM see's a ground signal from the swithes it knows to lock or unlock, depending on which ever circuit. The first place to look is on the passenger side under the door sill. There are clips under the plastic door sill so just pull upward on the sill. There will be a harness there with a few splice packs, make sure all wires in the splice packs are clean and intact. Other than that look in the door passthroughs. If nothing is found there remove the door panels and check for chaffed wires. Wiggle the harnesses also and see if the doors will unlock, if so then you know you are in the area.
Hope this helps.

[grape8pe]

Okay I went out and checked all the splices and everything looks good and super clean.

For the most part the lock button on the drivers and passengers side doesn't work. The unlock button always work. The doors will randomly lock themselves. This happens when the car is parked and off and while driving down the road. It's always completly random.

Does this sound like the BCM is bad? If so, how much does that cost?

[GregA]

Originally Posted by grape8pe

Okay I went out and checked all the splices and everything looks good and super clean.

For the most part the lock button on the drivers and passengers side doesn't work. The unlock button always work. The doors will randomly lock themselves. This happens when the car is parked and off and while driving down the road. It's always completly random.

Does this sound like the BCM is bad? If so, how much does that cost?

grape8pe,

Don't know if anyone has said it yet but - Welcome to the forum. I also got your PM.

I have a few links to the lock controls on this page (about 8 lines down in the table). There are schematics on those link pages.

If your locks work from other locking "inputs" (remote, turning & holding key in door), I would say your BCM is probably OK.

I would find the BCM and take a CAREFUL look at Pin C7 of connector 2 (the blue one). That is the pin that receives the signal from the door switches to lock. If that seems OK (pushed all the way in & clean), I would look at the door switches next, probably starting with the driver side. I usually troubleshoot this type of thing by "tapping" on the switches and tugging on the wires to see if I can make the problem reappear.

Let us know what you find.

Take Care,

[grape8pe]

Thanks for the info. When I started my car up this morning all the locks were working so I thought the problem was fixed. I was wrong though, they only work about 20% of the time.

I'll take a look at the connections to the BCM tonight and see what I find. Would a problem in one door cause both power locks to act up? How much trouble is it to access the door switches. Do I have to take the door panel off?

Thank again for all your help!

[GregA]

Originally Posted by grape8pe

Thanks for the info. When I started my car up this morning all the locks were working so I thought the problem was fixed. I was wrong though, they only work about 20% of the time.

I'll take a look at the connections to the BCM tonight and see what I find. Would a problem in one door cause both power locks to act up? How much trouble is it to access the door switches. Do I have to take the door panel off?

Thank again for all your help!

Yep - sounds like a loose connection somewhere. And yes, one switch could mess it up (they are wired together). Take a look at those schematics.

As for getting to the door switches, its WAY EASY!

Take a look at the picture on THIS PAGE. All you have to do is gently pry up on the edge of the plastic in the door switch panel and it comes out.

Take Care,

[grape8pe]

Okay, I've checked the switches and got nowhere. When I pulled out the BCM and started wiggling the wires, the locks started going nuts. I tried to check the light blue and white wires going into the BCM but could not get the problem to stop. After playing with it for about 20 minutes the locks are back to not working. Every connection looks super clean and has a solid connection.

Is it still possible the BCM is going bad on one of the channels going into it? If the problem is with the wiring, is it possible to place the harness that goes out of the BCM to the rest of the car? Once again, thanks for all your help!

[ponchonutty]

It sure is. Actually it is very common in the Venture. They are riddled with electrical problems. That's while GM redid the body and changed the name.

[grape8pe]

Originally Posted by ponchonutty

It sure is. Actually it is very common in the Venture. They are riddled with electrical problems. That's while GM redid the body and changed the name.

Thanks for being such a help. Are you this negative with all things in life or just when it comes to vehicles? I go for help in these forums because I look to find useful information from others who have had similar problems and not to find cynics griping and complaining with no real solutions. So what, I own a GM vehicle. I decided to buy American; sue me. Next time you post on these forums I hope it’s to help someone and not nitpick about GM vehicles.

[ponchonutty]

Hey, I buy Mexican too as you can see. I'm happy with my vehicles. I'm just stating the obvious. I see it all the time. I work at GM dealerships and my brother in law just sold his '02 Venture van with the same problems as you. I swapped out the BCM and it seemed to cure 90% of the problems but not all of them.

[grape8pe]

Okay, here's the latest on my problems. I had to take my Venture in for a recall on my passenger power sliding door. They looked into my problems said that most likely it was my body control module (BCM). They wanted to charge me $278 to replace and reprogram my BCM. I declined.

Here's my next set of questions. I have found several stores online selling BCM for my Venture ranging from $50-$120. I believe I have a BCM 3 because I don't have the security package. I have keyless entry and my keys are the PassKey3. If I were to purchase one of these online (ACDelco Part #10427831) @ $50, what programming would need to be done? Reading the forums in the Pontiac section, they mention something like a "Tech II" tool. If that's needed to program and new BCM, how much would a repair shop charge to program the BCM?

Here's the next question too. My wife hates that there's no audible or visual signal of the doors locking with the keyless remote. If I were to purchase a BCM 4 (around $120) and go through all the above mentioned procedures, would the horn or lights signal the doors are locked? Once again, thanks for everyone's help and advice!

[ponchonutty]

Well, that's all out of my league. You'd have to contact a dealer or decent mom/pop shop that's got the right tech tool.