'00 C280 stalls/will not crank
 

Twice in the past 2 months my mother's '00 C280 would not start. The starter would not even operate. Eventually the starter would energize and the engine would start and run fine. The most recent occurrence was today when the engine just stopped in traffic and would not restart. She described it as just shutting off, not sputtering or shaking as if there was a fuel or ignition problem. She also said the power seat would not work a few minutes prior to this (not sure if they are related). I don't think this is related to the crank position sensor, as in this case the engine just turns off. I am led to believe the problem is in the electronic ignition key lock (not the electronic key itself). Any ideas?:confused:

Sounds more like a bad battery OR alternator

Did she happen to notice if the battery light was or was not on before this happened? Measure the voltage of the battery with the car sitting and the car running.

The alternator warning light never came on during either occurrence. The first time this happened, the car was parked for a while, then when she returned and was ready to leave, the starter would not engage. So that's why I wonder if there is a DAS issue. She does not think the steering lock retracted or engaged when the key was withdrawn/inserted.

Lately my ignition switch has gotten picky about how I put the key in. If I put it with the unlock buttons to the left it will start fine. If I put it with the buttons to the right it won't start. However, once started it never shuts off. I am guessing the security system does not check the RFID chip in the key after the car is started. I don't really know though. I would measure the battery voltages anyway since that will address what MB Doc said and he is often right.

These symptoms sound exactly like my 2000 C280 when it needed a new crank shaft position sensor (by the fire wall on the bell ? housing). Random non-start. You just wait a variable amount of time then it would start and behave normal. This progressed to a total engine shut down while driving. The car would suddenly shut off. Sit for a bit and then it would restart and drive normal until the next incident.


Edit: Recalling my situation, my car would crank, but would not start, until some arbitrary amount of time passed. So as you thought, probably something else besides CPS.

I checked the battery. With the engine off the battery read 12.4V. With the engine on the battery read 14.3V. It appears the battery is ok. I tried different insertion orientations of the key, and in one instance the steering lock did not release. It worked fine every other time.

I think those voltages look good. So that would mean the alternator and battery are good. The charging voltage is good. The battery voltage maybe a bit low, but good enough. I think fully charged it should be resting voltage about 12.7 or 12.8V.