Key won't turn in C55 Resolved
Thread Starter
Member
Joined: Nov 2005
Posts: 137
Likes: 0
From: San Diego, CA
Key won't turn in C55 Resolved
Last week, my key would unlock the doors but wouldn't turn when attempting to start the car. A Mercedes technical came out to diagnose and ended up giving me a ride how to pick up the second key.
The second key hadn't been working properly for over a year. It would start the car but the dashboard and electronics in the car wouldn't work. But the car could be driven!
The dealer wanted to replace the EIS but I decided to go with ordering a new FOB key first.
Lo and behold, the new key works!!! So, the EIS is fine and it surprised everyone. So, if you have problems with your key, be sure to try replacing the key BEFORE replacing the EIS.
The interesting thing is that if I drive the car with the original key that isn't working properly the car doesn't register any miles! Unfortunately, my car already has 130,000+ miles
The second key hadn't been working properly for over a year. It would start the car but the dashboard and electronics in the car wouldn't work. But the car could be driven!
The dealer wanted to replace the EIS but I decided to go with ordering a new FOB key first.
Lo and behold, the new key works!!! So, the EIS is fine and it surprised everyone. So, if you have problems with your key, be sure to try replacing the key BEFORE replacing the EIS.
The interesting thing is that if I drive the car with the original key that isn't working properly the car doesn't register any miles! Unfortunately, my car already has 130,000+ miles
Member
Joined: Jan 2013
Posts: 241
Likes: 1
From: Edmonton
2003 C32 AMG
I don't want to call your bluff, but it's not technically possible for the vehicle to be driven without it logging miles. The EIS (or Electronic Ignition Switch) is not the only control unit that this number value is stored in, and is cross referenced by the vehicle computer. For example, if the values in the EIS do not match the values in the ME-SFI control unit, or the can bus gateway you will have drive authorization issues.
Super Member
Joined: Oct 2008
Posts: 837
Likes: 25
From: seattle
1990 300ce supercharged and intercooled
I recently had a car in my shop that did this. What I found was that after the key was inserted in the igniion and drive/auth was released and the car started the key status in the eis would switch to being unauthorized. This would turn off the interior ciruit 15c. Basically the EIS would tell everything to turn off. Circuit 15 and 15r are a physical output not a can message and would stay on and the authorization for the engine is a one time deal on startup so it would run. The rest of the car was simply off.
Any problem with keys or starting diagonsis starts off with having to keys. If both do the same thing then it is most likely and EIS.
Any problem with keys or starting diagonsis starts off with having to keys. If both do the same thing then it is most likely and EIS.
Member
Joined: Aug 2010
Posts: 167
Likes: 1
From: Elizabethton, TN
A teal Vespa with tassles and glitter. You know you're jealous.
Had the same thing happen to me in my C32 a while back. Drove to work with no issues. Went to leave work and it wouldnt turn at all. Insert the key and you couldnt hear anything disengage. I didnt have a spare key at the time either. 
.
Had a coworker take me home, thankfully I had my truck too, I ran out and got a new battery for the fob and tried it and it resolved the problem. Havent seen it since.
. Had a coworker take me home, thankfully I had my truck too, I ran out and got a new battery for the fob and tried it and it resolved the problem. Havent seen it since.
Junior Member
Joined: May 2014
Posts: 37
Likes: 2
From: SO FLORIDA
2010 E350 SPORT SEDAN, 2006 C280 4MATIC- SOLD 2009 FORD F-250, 2015 KIA OPTIMA HYBRID, 2013 MB E550
Last week, my key would unlock the doors but wouldn't turn when attempting to start the car. A Mercedes technical came out to diagnose and ended up giving me a ride how to pick up the second key.
The second key hadn't been working properly for over a year. It would start the car but the dashboard and electronics in the car wouldn't work. But the car could be driven!
The dealer wanted to replace the EIS but I decided to go with ordering a new FOB key first.
Lo and behold, the new key works!!! So, the EIS is fine and it surprised everyone. So, if you have problems with your key, be sure to try replacing the key BEFORE replacing the EIS.
The interesting thing is that if I drive the car with the original key that isn't working properly the car doesn't register any miles! Unfortunately, my car already has 130,000+ miles
The second key hadn't been working properly for over a year. It would start the car but the dashboard and electronics in the car wouldn't work. But the car could be driven!
The dealer wanted to replace the EIS but I decided to go with ordering a new FOB key first.
Lo and behold, the new key works!!! So, the EIS is fine and it surprised everyone. So, if you have problems with your key, be sure to try replacing the key BEFORE replacing the EIS.
The interesting thing is that if I drive the car with the original key that isn't working properly the car doesn't register any miles! Unfortunately, my car already has 130,000+ miles
TO GIVE ME AN IDEA OF THE COST OF A NEW KEY, HOW MUCH WAS YOURS? I LIVE IN FLORIDA BUT IT'LL GIVE ME A BALLPARK... THANKS
T=
