Hi,

I've got a 96 E300. This morning, as I was driving, the engine seemed to stumble for a moment, and the check engine light came on briefly, before returning to its normal "lamp defective" message. I believe the message was "Check engine electronics", although I may have imagined this because of the many electrical problems I've had so far (fried wiring harness, alternately flashing mirror lights, perpetual lamp defective message that seems related to a bad instrument light I can't reach). At any rate, I figured I'd better get home before turning it off. When I tried to restart, the key would not turn at all.

Is this likely to be a mechanical problem with the lock/tumbler or an electrical one?

Thanks in advance for any help.

Julian