I've got some central locking issues on my W210 2001 Sedan. When I lock the car, all seems ok. The pump goes on for a couple of seconds, and all 4 doors, the tank lid and trunk locks fine. But, when I press unlock, all 4 doors unlocks fine, but the tank lid stays locked for 7-8 seconds before it unlocks. The same goes for the trunk. It locks fine, but when I unlock it, the lid pops open and I can hear the pump go for many seconds . As long as the pump is doing its business, I can not close the trunk. I have to wait for the pump to do its thing before I can close it.

So, what I did was to switch the connectors which controls the driver side door and the tank lid. The unlock problem moved from the tank to the driver side door. All locks fine, but with unlock the 3 doors and the tank lid unlocks at once, while the driver side door took many seconds to open. I quickly came to the conclusion that the PSE is the problem, and ordered a used one from a salvage yard. I thought maybe the trunk problem also came from the faulty pump. However, the new pump came today, but the problem persists. I noticed a significant shorter unlock time though when I turned the pump on the side or whatever, but overall there is no difference in the lock/unlock situation... other than this new pump doesn't work all the time. I have to turn it upside down and give it a knock once in a while to get it started, so I'm returning that one...

So, I'm wondering if any of you guys have a idea of what causes this problem. I'm thinking if there was a leak in any of the tubes, shouldn't the pump have the same problem with locking the doors? Any suggestions on what to try next?

 

OMG why isn't this clown banned yet?

 

Did you use the same electrical connectors? What often happens is the foam box that holds the pump gets wet from a spill and water collects on the bottom and causes the lower electrical connector pins to oxidize and burn out. When you disconnect the connectors, take a close look at the pins and you may find that some have disintegrated I bought a used pump that had the connectors still attached with the harnesses cut. I spliced it in carefully one wire at a time. That solved my problem. Mine had gotten wet with from hurricane Sandy. The door locks worked but trunk would work very rarely. I'd hear the pump come on at random times as well.