Central Locking Unit - Driver Door Works, Not Others
 

I replaced my CLU with a used one from eBay. It worked fine for 3 days, then the three non-driver doors and trunk stopped working. The driver's door and gas cap worked fine.

So, I got another one from my local auto wrecker and the same thing happened! All was well for a few days, now the driver door and gas cap work but not the three other doors and trunk.

On the first replacement, I traced it down to one of the vacuum - pressure pumps was not functioning, the one for the three doors and trunk. The line was fine, it held vacuum and would work the locks manually.

But, I find it strange I would have the same problem. What are the odds?

Can anyone shed light on this?

Many thanks,

John

Is there possibly bad luck surrounding you and CL Unit's dear Sir? I have no real answer for you beyond what you have already probably thought of and looked at. Good luck :/

I am afraid you are right about SOME bad luck with the car. But, other problems, and they are numerous, are yielding to fixes, so I am encouraged.

Thanks for replying,

John - :)

This might be a shot in the dark but what happens when you push the unlock button twice? Does it open all the doors then?

Doug

Two Click Key Fob
 

No, the 3 passenger doors do not unlock. Thanks for the suggestion.

John

Progress to Date
 

I have a progress report.

1. Removing the two hoses and testing pressure and vacuum from the CLU, there is both pressure and vacuum on the small tube. There is only pressure, no vacuum on the large tube.

The small tube locks and unlocks driver's door and gas cap. The large tube locks and unlocks the three passenger doors, so this is consistent with the problem.

2. For the large hose, applying pressure and vacuum manually locks and unlocks the doors, respectively, and the hoses hold both vacuum and pressure. So, the problem is in the CLU or wiring circuit.

3. Finally, I was cursed with the diagnostician's gremlin, intermittency. At this point, the 3 passenger doors started to lock and unlock! So, I plan to wait and see if the problem comes back.

It could be that the vacuum - pressure system gets out of synch. If so, maybe in testing I got them back in synch.

Again, any thoughts on this from someone who knows about it would be helpful.

Stay tuned!

John

:confused:

Two Weeks Later
 

Everything works fine. I must have done something right when I diagnosed the problem two weeks ago.

Unless the problem comes back, I am happy.

:)

Thanks for the update, keep us posted. Dealing with a similar issue myself. Swapping CLPs didn't help.

Wiring Connector
 

I should mention that on the original, water-logged CLP, one of the three wiring connector plugs had some corrosion it it. I cleaned it out with contact spray, but the symptoms did not go away immediately, only after more experimentation.

So, maybe my problem was fixed by finally getting a good electrical contact at the connector.

The connector was one of the end ones, not the big one in the middle.