W203 Will Not Crank - Newbie Post

[JB1973]

Hi All,

Got a real problem with my 2001 C200K and I would be grateful for any help advice etc......

The car has been no problem recently and then, all of a sudden, refuses to crank. All lights come on on the instruments, and I have checked the voltage across the battery as around 12.2V, I have also check all the fuses and they appear OK, but the car will not crank. Strangely, the engine fan appears to go on full power, which I don't think it did beforehand - certainly not from a cold start.
I still get the red lights on the key fob, although the central locking doors appear not too work also at the moment!

I have ran carsoft and that comes back as saying that the EIS is OK, although it cannot interrogate the ECU

Has this happened to anyone else ? Any pointers would be very gratefully received

Cheers

 

[nickcc101]

Have you tried turning on the headlights and looking to see if they dim right down when trying to start. If they do then one of the cells in the battery is failing. You will still get a 12v reading on your meter until you put the battery under load then it drops to almost zero.

 

[BlackC55]

It sounds like the engine control unit is buggered.

The fan runs at full speed when this happens.

 

[mr. shr]

Could it not be the Crank Position Sensor as I understand this to be a common failing point on Mercs?

 

[BlackC55]

I very much doubt it