Whats up guys, hopefully someone can help me out with this problem.

About 3 months ago my battery started to drain randomly, after some trial and error I have narrowed it down to the passenger seat module. Left it unplugged and for 2 weeks it solved the problem.

But now a new problem has came up. When I try to start my car it turns over, but gets stuck turning over. Even when I turn my key to the off position it still keeps turning over, it only stops when I take the key out.

But...this problem only happens when I drive my car for more than 15 minutes then turn it off. If I let it sit for about an hour it will start right up, but it has to sit for a lil while first.

I've had my battery and alternator tested, but nothing was wrong.

Any ideas?

 

Some of these cars have an automatic starter, for example, our SLK230 keeps cranking until the car starts regardless of how long you hold the key. If it doesn't start, it will crank for a while and then stop. Is this what you mean? Is it cranking and not starting or is it cranking and starting and then still cranking?

 

Does the car actually start when it gets stuck turning over? If so, it could be something as simple as the solonoid. I believe all the W203's have the automatic starter (i.e. it will keep cranking until it starts, even if you take your hand off the key), so there also could be more to it...

 

Yeh, if it's still turning in the off position thats strange indeed.
As stated, if you turn the key to the start position it will indeed keep turning over till it starts, but I don't think thats what he means.

Mine occasionally sputters and won't start or starts badly, but seems to cure itself if I shut it off right away and start again.

I'd say either the starter or the EIS.
I'd start with the selenoid since it's something I could DIY.
New EIS can only be installed with the help of a mechanic with star system and the switch has to be ordered by VIN # + it's like $500.

 

No, the car doesn't start. Just sits there trying to turn over until I take the key out.

Something else strange happened the other day. I went to meet a friend at the car wash, knowing my car prob wouldn't start if I turned it off I left it on. I drove from my work, maybe 2 minute drive, parked it at the car wash and let it run for maybe 10-15 minutes then the car just shut off all by itself.

And like usual, it wouldn't start. O, and my car towed in the process

 

CPS....classic symptom.

 

CPS= Crank Position Sensor

 

Thanks! Just replaced my CPS 3 days ago and no problems at all so far!

 

Anyone ever had the CPS replaced and have it go bad again (within 6 months). Had mine changed and now have it cranking when trying to start, it eventually turns over but not sure what to do next.

Any thoughts would be great.

Pat