Dealer can't figure it out !

[VigiDude2]

I have a 1996 C280 in which the lock have stopped working. I have the Infared system with the RED/GREEN Led on the rear view mirror.

I had tried everything that I could think of and finally took it to the dealer. The dealer spent 1 1/2 hours before they called to see they should spend the next 3-4 they thought it would take.

That's a possible 5 1/2 hours x $92 = $506 for my locks.

The dealer says that there has to be a leak in the system to one of the doors and if one of the doors has a leak then none will work.

So I took it home and started playing around with everything that I could think of out of the ordinary and came up with this.

If I manually push the locks down by hand, then hold the TRUNK release button, all of the doors unlock ! So I have air going to each door.

Any ideas ? This must mean that the pump is working, the lines are working, any electronics are working. The LED flashes RED-GREEN at the same time when pressed.

But, the gas theft deterent works while using the key remote...

Help please !!

Thanks

[joe p]

Ok, central locking 101.

Step 1, unplug the pump for a few minites, this will reset it.

Step 2, check all external locks with the blade key, see what works and what doesnt. All funtions including valet for the trunk.

Step 3, summer opening (if equipped) do any of the functions work?

Step 4, go back to step one and see what dosen't work, start there. The remote is sort of a add on in those years and may or may not indicate a lock problem but a ata problem instead. One quick test for the c/l pump is being very quiet and activate the lock switch, listen for the pump, even if the locks dont move. If you dont get a pump, manually lock it and switch inputs and listen. Keep in mind the central locking and ata and convience features are all individual systems linked together and work more or less independently of each other. I've replace a few central locking switches here and there and a few pumps as well but the key to these systems is being very through on the function tests of all related systems.


Joe

[VigiDude2]

Joe,
Thanks for the detailed reply. I have already performed the following:

~ No functions work with the blade key or valet key except drivers door only.

~ The remote does not unlock or lock anything, but does activate something under the rear seat. The pump itself or the solenoid or electronic that activates the pump. Regardless, I can hear a switch when pressing the remote. I have taken the back seat out and confirmed.

~ I have pulled fuses and the battery for long periods of time to reset. Sometimes the RED/GREEN led will blink corectly, but then immediately go to both colors flashing and I am back to zero.

~ The head rest in the rear are working and I mention because I think it's the same pump that releases the rear head rest.

~ The trunk works fine

~ The alarm works fine

~ I can press the remote and then enter the car without the key and it will not start....built in I know, but function of key is working.

~ I can manually lock the doors and unlock with the trunk release button so I know that the door locks are fuctioning.

~ The lock/unlock swith in the car is not doing anything. When I press it, I hear nothing anywhere....I think this has something to do with the situation, but I can't figure why it would block the other ways of unlocking the car.

What else can I try ? Is unplugging the pump more than just disconnecting the battery?


Thanks for the brain power

[VigiDude2]

To The Top.....Still Strugling, Dealer wants to give up unless $92 per hour until fixed.

[joe p]

E mail me to remind me to check WIS for a convience module in that model. It sounds a lot like the 140 cars I've seen do something very much like that.


While your at it, swap in a used switch just for grins.



Joe

[VigiDude2]

Finally figured it out...

My TRUNK switch was stuck in the open position....says the tech.
Took it out, cleaned it up and the locks are back to normal.

Strange one year troubleshooting and a few hundred bucks !