Emsflyer84

Hey all,

So my 01 E430 has a funny issue. When I unlock the car with the remote, everything unlocks fine but the driver side rear door and the trunk take longer to unlock then the rest of the doors. If it's very cold outside, sometimes the rear door and trunk won't unlock at all and I can hear the vacuum pump running until it times out, trying to unlock. The other three doors unlock fine. I also always hear a hissing air leak sound coming from the rear passenger door somewhere every time I unlock the car. Could I have a leak in the vacuum system? What explains the cold weather issues? Thanks guys!

01BlackE320

If the hissing sound is from inside the door, then you need to open up the door panel and find the leak. Make sure the hissing noise isn't coming from under the passenger side rear seat. That is where the central locking pump is. My pump crapped out after getting wet from hurricane Sandy. I replaced it with a used one I found on eBay

Emsflyer84

It could be coming from under the seat, but it's definitely louder on the driver side.