My E430's Electronic Key would not turn. Steering wheel would turn with key in ignition and lock when removed. Someone in this forum said to clean the surfaces of the infrared sensor on the key and on the little entry door of the ignition with a pen. I took a softer approach and cleaned them with a Q tip instead and presto, the key turned! There are still scratches on the surfaces so I don't know how long it will last but at least I don't have to tow the car.
In searching through 6 pages of postings, I saw a lot of questions about this problem, some from people stuck on the road, with few suggestions on how to resolve it other than to replace the ignition or keys so I am making this a stand-alone posting rather than just a reply to make it easier to find. (Sorry, no pictures of the Q-Tip DIY.) Finding the solution took 5 hours. Fixing it took 5 seconds.
I just used it dry. I don't think I can damage the surface with some kind of mild solution but I don't want to leave a film on it. Some said they used WD40 on their ignitions but they weren't W210s and were probably mechanical problems. I am planning to call the dealer and ask what solution would be safe to use. I'm not sure the dealer is the best source for that information especially since the service manager did not offer any free suggestions for how to get the car running when I called. Otherwise, I will put a mild detergent on a paper towel and wipe it off. I have started the car about 20 times since doing the q-tip trick with no starting problems.
I saw quotes on this site of $93, $784, and $2000 to fix this. So far, I have spent 5 cents and a half day's vacation.
Thinking about this some more, I see two possible reasons for this working. I cleaned the little window on the key fob and ignition switch but I also pushed the window into the switch with the Q-tip. I'm not sure which did the trick. Yesterday, the key would not turn twice. I used the same technique. It took 4 or 5 tries to get it to work this time. Since someone's auto club got their's running by inserting a ballpoint pen in the ignition switch window, I am thinking it must have been that action that really allowed the key to turn. I'm going to replace all or part of the switch and/or key fob.
Thanks for the update. Mine has done this once. I rubbed the end of the "key" on my pants leg and then it worked. It seems that I may be headed down this road. What's really weird is that almost every time I read about a problem with these cars, on this forum, it happens to me! My friends tell me to stop reading the posts! It is creepy. I read about the window regulators... one died. I read about the CPS... it died. I read about the brake light switch... it died. I read about the lamp problems... started happening, first with brake lamp sockets and then with bulbs burning out. Then I read your post about the key... and now it has happened to me! See what I mean? Really creepy. Now, if you win the lottery, tell me about it and then it will happen to me. Yeah, right!....
Best regards (and Happy New Year), Peter
First time poster. Bought 2000 E430 in 3/00 now 48k miles
I've read back a few hundred posts but don't see anyone resolving the "key won't turn in the ignition" syndrome. My car started doing it at 40k miles. So far I have put up with it but my wife hates to drive the car.
Any readers yank out the switch and do a post mortem? Maybe there is a rebuild / upgrade possible for the switch?
FYI
Brake switch 2k
My back windows fell in the doors 35k
MAF sensor 28k
My motor mounts are shot 40k
Chips in the paint
Broken fog light. Cats head did that one. 41k
I talked to a Mercedes mechanic and he said its working after cleaning the lens was coincidence. I'm not so sure. He told me to buy a new key since we lost our second key. I'm in the process of doing that now - $184. If that doesn't work, I'll replace the switch. $485+labor.
Went to the site recommended by the moderator and got this response (for a fee.)
EIS (the ignition switch) is failing. Seen the micro switches do this and I've seen the IR receiver do this as well. As long as the steering lock works, just the EIS should do it. however, in order for the key to be released for turning, EIS MUST see the return signal from the ESL (electronic steering lock) That signal can be tested but it requires a scope and knowing what you are looking for. On a intermittent fault, good luck actually catching the glitch in the act.
My recommendation? Replace EIS and 2 new keys.
Also, more information on how it works is here: 80 RCL/ATA/PSE
Linear Mode
