MWWarlord

I'm having an unusual issue with my driver's side door lock. I'm having an intermittent issue getting it to unlock. It locks with no problems at all. However, sometimes it doesn't unlock. If I physically flip the locking switch to the unlock position, it will then function normally for at least an hour+. I've even run into this issue when putting the car in park, and the car tries to automatically unlock the car. I can hear the actuator working as normal, but nothing happens. I have not tried to use the key (as I have a cover over my keyhole). However, I'm pretty certain that the key would work. Any ideas or suggestions would be greatly appreciated.

rrwirsi

A thought: If you have the Auto Lock selected as ON in the DIC Control #4 Options now, try turning it OFF and see if that has any affect on your issue. Do the opposite if originally selected OFF. The electrical gremlins in the C5 are at it again.

MWWarlord

I'll give it a shot, but I don't think that's the issue. The passenger side works as normal, and I have experienced the issue with the fob, door unlock button, as well as the automatic unlock when I shift the car into park. I can hear the lock trying to actuate, it just doesn't open. I feel like this could be a mechanical issue rather than an electrical one. Especially since manually unlocking the car via the lock lever on the door temporarily fixes the problem. I'm not sure what could cause this, or how to fix it.

ThomasR

Old hard grease.

Missileboy

It's pretty easy to pop the door cards off. I would remove the door card so you can see the mechanism. Make sure it is clean and no corrosion etc. Spray some lube on the action and it should be okay unless something is broken or starting to fail. You need to see it to completely understand what is or is not happening correctly.

wamara

Warlord, I had a somewhat similar problem with my '02, which may be sufficiently analogous to yours such that this may be useful to you. My passenger door would unlock, with both the key fob and using the lock/unlock button on the driver's side armrest, but wouldn't lock with either control. I would have to manually push in the lock's "flipper" lever to get the door locked. I ended up removing the control module inside the door (fairly simple once you carefully remove the interior panel) and sent it to ABSfixer for repair. If memory serves the problem was with a relay, but it's been a few years now so I'm not positive; also don't recall anymore if I "heard" it attempting to work or not.
Since your lock function does work, I wouldn't think this is a mechanical/needs-to-be lubricated problem (although it couldn't hurt). Also given that the problem is intermittent, then again makes me think the problem is electronics/module-related.
HTH and good luck.

MWWarlord

Thanks for the suggestions. I was hoping someone might knew exactly what was going on. I guess the next step will be to remove the door card and get a closer look at what's going on.

PlanoLeMans

Here is the trouble shoot flow chart for the driver's door lock.

PlanoLeMans

Here is the schematic you will need

Vetteman Jack

Moved to C5 Tech.

Jacks02

Had same issue on my 02. Tried WD-40 on the "flipper" assembly without taking door apart, wiped overflow with a rag, and it now works as designed. .