nathandsewell

I recently bought an S430 used from a local dealership. I absolutely love this car so I have decided to look elsewhere for help since no shop in town or my shop can figure it out. I work as a mechanic at a Jaguar shop currently and have previously worked in European specialized shops but not so much with Mercedes.

Here is the problem: When I turn the key to start the car, it starts to crank over for maybe half a second then just quits. I then have to turn the key off and try it again. Sometimes this will happen repeatedly for a few tries and then the car will start and run with no problem whatsoever. Other times it only does it once and then starts. It has done this since I bought it and so I had the dealership replace the CPS and it still does it. What makes the diagnosis so hard is that this problem is completely random, it doesn't matter if its raining, dry, hot or cold. It wont do it for days but then some days it will do it 5 times. My only thought now is maybe the starter solenoid???

ANY help and suggestions are very appreciated.

vmystikilv

Sound like a bad key or transponder in key . Basically the alarm system . That would be my first guess

nathandsewell

I never thought about the transponder in the key, something with the alarm did run through my mind but I wasn't sure. I will look into it

E55Greasemonkey

Do you have a second key? If not, you may want to order another one..

nathandsewell

unfortunately, when I bought the car it only came with one key fob. and the metal key insert is missing. I have been meaning to check with the local MB dealer on a replacement key and another fob.

tusabes

Yep
EIS

corkshoppe

order key , you can over the phone but you will need to pick it up with proof of ownership. but that sholud fix the problem.

Critter

From my experience you must order fob from dealership personally, provide proof of ownership as well as ID for yourself as being the owner of the car, along with the VIN of the car. The fob will come in from Germany with all data in the key fob, ie, door opening function and set up for any other options/functions that are applicable to your car. When picking up the fob from dealership you must again show ID that you are the registered owner. In my case after inserting key for first start the car and key were somehow "mated" and from then on the key less function was working. Good Luck

marktan

When I had my C32, it did the "crank-stop, remove the key,re-insert key and start again and it started up" issue, especially on cooler damp days. Turned out to be the battery that needed to be replaced (lower inconsistent cranking voltage). Not sure if that is your issue, but perhaps have the battery tested to see if the CCAs have dwindled "just enough" to cause issues.