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Key won't turn in 2003 S500 Help

6K views 12 replies 5 participants last post by  iSteve 
#1 ·
My key will not turn in my car. Some days it takes about 20 minutes before I hear a click noise and I am actually able to turn the key. Now my car isn't reading the key at all. Also that key will not lock or unlock the doors. Does anybody have any idea what this may be?
 
#2 ·
I've moved your thread to the proper section so you can get a better answer.

To be honest, since it won't unlock or lock the doors, sounds to me like the battery is dead.

Have you tried your other key (you should have two)?
 
#3 · (Edited)
The key needs good batteries inside it for lock and unlock but does not need batteries to start the engine as the EIS provides the small electrical current required for key recognition, so this is a seperate issue. Possibly the EIS or the shift lever module.

Have you ever spilt a drink or placed anything wet over the shift lever? And do you have a second key to try?
 
#5 ·
Sadly then we are left with a potential EIS (Electronic Ignition Switch) problem and only a dealer can rectify that one.
 
#7 ·
Do they now lock and unlock the car at least, since you put new batteries in them? And is your car battery OK?
 
#9 ·
LOL OK, first off recharge the car battery or get a new one then we can start over from that point. With the car battery dead you cannot test the keys on anything, lock/unlock or start.
 
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#11 ·
Not a bad idea but expensive, however a bad quality battery causes more problems with these modern cars than anything else I can think of. Anything below 12v and all hell breaks loose with the electronics. The gremlins have a real birthday.
 
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