Power Door Locks: Lock, but don't Unlock

[chuckk_]

Hey everyone - I've read a plethora of posts on here for electrical problems, and several of them mentioned this specifically, but it was always buried by so many other problems that (as far as I could see) it was never directly addressed.

Anyhow - All other electronic controls function properly on my 2002 Bonn SE, but the only controls that don't work are the interior door locks - they lock, but don't unlock. It is the same on the passenger side and driver side.

Other (possibly related/symptomatic) thoughts:
It has an OEM security system that arms when I lock the car, but I don't have remotes. If by chance I reach in through the window to unlock the car, the alarm will sound. If I start the car to make the alarm stop sounding, it does so, but the door locks will erratically "flicker" locked/unlocked as I drive. This continues until I put it in park, shut off the car, get out, lock it with the key, then unlock it with the key.

I thought maybe the unlock function being disabled might be a feature of the OEM security system (that I didn't fully comprehend because I don't have remote locks), but the more I read, I started to think this was actually a problem.

Thoughts? Is there a fix for this?

[stevew9983]

It is possible that you do have an electrical issue for the power door locks not getting the signal from the drivers door module to unlock the other doors. It is also possible that you have the OEM alarm system looking you out since you dont have the key fobs.

Possible fix ideas:
1. Get the car scanned with a good code reader/snap-on diagnostic tool and see if you have any codes in the Drivers door module. If no codes are present let me know and I can post a wiring diagram for the door locks on the car for you to check. If codes are present also post, i have access to Alldata and Mitchell on Demand repair software and can help you diagnose this issue.
2. Search ebay for a nice car alarm/remote start option or just an alarm that will offer lock and unlock on the alarm remotes. Adding an aftermarket alarm takes some skill and ability to read a wiring diagram and it bypasses your oem alarm system which should allow you to lock and unlock the car doors no problem with the alarm remotes.


Hopefully this reply back helps you figure out what is going on, if you need anything as far as wiring diagrams or repair info from either of those softwares i have, let me know.

[stevew9983]

also another possible idea is a the door unlock relay the car has, i forgot all about those.

[chuckk_]

wow, all great tips. thank you so much for the info. I think the most tangible solution is to check the unlock relay... I'll do that in the next couple of days and will let you know what I find. The other two sound like potential projects, and since I just entered my senior year in college, I don't have a lot of time for more of those But I'll keep this post in mind and will re-visit it when I have a little more time on my hands. Again, thank you.

[chuckk_]

I'm giving this topic a "bump" because my problem just changed, and now it's a lot more annoying so I want to get it fixed soon.

New info:
I realized this spring that my driver side floor is getting extremely wet every time it rains.
It seems like the top of the door isn't sealing right because on occasion I'll see a big drip fall from the door jamb, but I also notice a small trail of water forming on the plastic panel underneath the door when I open it.

- NOW my driver-side power lock switch does not work at all!
- The passenger side switch still does the "locks doors but won't UNlock them" thing.
- But even weirder - when I use the central door unlock feature (turn key twice to the right), I might be crazy but I swear it's actually re-locking the doors. I think this only happens after the OEM security system has been armed.

So aside from fixing this leakage problem, what's going on with the door locks??

- I haven't 100% ruled out the switch itself, nor the window/mirror/lock module.
But I don't think it's the module because the window and mirror controls from the driver side still work fine.

- A bad lock or anti-theft relay might explain this.
Question 1) Is this controlled by the same relay?
Question 2) Where are they in the car?
- Or could it be a wiring issue caused by the water leakage?

Thanks again for any and all tips!

[02ssei]

I had a problem with my locks not unlocking. It all came about from my fiance leaving the window down. Killed the lock switch and the window switch.

I'd suggest getting a switch from harofreak00 and see if that works.

[chuckk_]

Just making one last post before I start replacing parts.

Recap:
So, since I bought the car, it has had some odd electrical issues. The power lock switches both would lock doors, but wouldn't unlock doors. Also, my locks have a habit of "flickering" locked/unlocked EITHER the morning after it rains or while it's extremely humid, or after I set off the car alarm.

With that as the jumping off point:
After one rainy night where I accidentally left my driver side window cracked, my driver side power lock switch stopped working all together. The driver-side window controls stopped functioning for the other windows. Also, the "flicker" issue started happening more frequently.

I had an obvious door leak that I fixed according to the directions on this board.
After the windows stopped working, I fixed them using the "splice the tan wires together" fix on this board.
but I'm still dealing with the lock issues, and I want to fix that now.

so, does anyone think it's the door module? The lock switches? the exciter module? or anything else?
Any feedback is appreciated.

[jongwong]

I have the same problem but mine is just the opposite......I had the leakage issue, fixed that.......corroded splice box on the tan wires, fixed that.......and everything back to working except the power door locks........mine will unlock just fine, but I cant get them to lock using the inside buttons on the driver and passenger doors. Any suggestions of what might be causing this and any fixes? Thanks in advance for any help!

jongwong