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Marty, Mercedes Technician
Category: Mercedes
Satisfied Customers: 53945
Experience:  Bosch Certified Master Tech. Over 35 years experience.
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Key will not open or close doors, opened door with metal

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key will not open or close doors, opened door with metal key, alarm went off. Can start car and drive with alarm commong on and off for about 5 minutes. When pressing the open on the key the red light indicator still goes on. I was hoping dead key battery, does not look like that
JA: Did you test the battery with a voltmeter? And have you ever changed one before?
Customer: Have not tested the battery, can do so, i have a voltmeter
JA: What is the model/year of your Mercedes?
Customer: 1998 e320
JA: Are you fixing your E320 yourself? What have you tried so far?
Customer: just happened for the first time, of course in a grocery store parking lot, drove home it is quiet now, the key is still dead
JA: Anything else you want the mechanic to know before I connect you?
Customer: been having trouble with the windows working on and off as well as the seat adjustment

Hi, my name is***** will most likely be a fault with the PSE module for the door locks and alarm. The module is located under the rear seat cushion next to the battery. It is inside a foam encapsulation. Usually you will find that water has found it's way into the module and has shorted it out. This would also account for the other problems you are having.

Let me know if you have any questions. Kindly rate my service in order for the website to credit me for helping you.

Customer: replied 10 months ago.
What do you do about it? I certainly can locate it. As a old aircraft elec tech sometimes it is corrosion? Otherwise can this part come from the salvage yard and replaced without needing a mechanic?
Thanks this makes a lot of sense.
Customer: replied 10 months ago.
Going out of town in one hour back next week, can we restart then?

Hi Bill, it's usually best to just replace it rather than trying to repair the module. You can usually find new and used ones for sale on ebay.

Let me know if you need anything else.

Customer: replied 10 months ago.
Any thing about replacing it?

No, it's plug and play.

Hi Bill, just following up. Did you get this repaired yet?

Customer: replied 10 months ago.
Marty, sorry for the delay. I looked at the vacuum pump PSE and everything was in place with no moisture. The original problem has been the windows, front only, not operating, the trunk not opening from the dash, the seats not moving and the mirrors not working. This has been going on for some time and full function comes and goes. Right after I looked at the PSE all functions came back on for about two short trips. There is a short somewhere.

It's not a short, Bill. The problem is caused by a corruption in the controller area network. Try disconnecting all of the electrical plugs to the PSE module and see if some of the items start working. If they do, it means that the PSE module is corrupting the network.

Hi Bill, I'm just following up with you on this question. Did you ever get this sorted out?

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