Intermittent no-start, 2002 E320s4
 

Has anyone run into something like this? 2002 E320 wagon, 210 body, 129k miles. Every few months the car will not start. battery is fine. Both keys work the same. Occurs when my wife is making several stops. When the key goes into the start position, all the warning lights come up, but that is all that happens. No crank. No click.
The car will re-start later, sometimes an hour later, sometimes 5 hours later. the battery is fine, and the car has always re-started, later.
The car has been into a good MB dealer, but there are no deffinitive codes. The possible culprits are electronic Ignition switch, intermittent starter, engine management module, harness.
Until I can get someone with the SDS diagnostic computer at the car when it is no-start, I don't know where to start.
Thanks for looking,
Paul T

If it fails to start when the engine is hot and restarts when the engine has cooled down the likely culprit is the CPS.

That's usually true if it cranks and wont start, unfortunately the OP has a no-crank condition. It very well could be any one of the things listed as possible culprits.

I think it depends on the condition of the sensor.

no start
 

k40 relay?

k40
 

1) The shop did not think it was the crank sensor, since no-crank is the real problem

2) I replaced the starter relay, which is in the fusebox or connections box on the passenger side, just forward of the windshield. I don't know if that realy is known as the k40. The shop also mentioned the k40 relay as a possability.