2000 SLK ignition problems
 

I have a 2000 SLK 230 and lately I've been having problems trying to start the vehicle. I would insert the key into the ignition, turn it, but nothing happens. All the lights on the dash will come on, headlamps work, interior lights work fine. It first started doing this a few months ago, but would always start after a few attempts. Lately, I'd have to wait a few hours, re-insert the key and it would start. I already changed the K-40 relay in the fuse box on the driver's side of the vehicle. What else could be wrong ? It's really starting to baffle me? I even tried wiggling the gear shift knob in neutral while trying to turn the key on with my left hand thinking maybe it was a possible nuetral safety switch problem? It started and drove fine today, until I parked it, then went to restart it about 15 minutes later after coming out of the grocery store and nothing happen. I really need your help ASAP. :confused:

Crankcase position sensor perhaps?

how old is the battery in the car?

Sounds like the car has an automatic transmission??

For the starter to operate on that car the ignition switch must send signal to the fuel computer.

The trans computer must send signal to the fuel computer.
The trans shifter must send the same signal.
Then the fuel computer will send signal to the starter relay.

HAS the complete car been scanned for problems??