Hello,

I have a 1997 E320. It has the six cylinder with the oil filter at the firewall. I also have a metal key for the ignition. Here is the problem:

I drove the car about 100 miles, freeway and got home and all the dash warning lights, radio, climate control stayed on with the key completely out of ignition. A loud buzzing sound coming from the engine sounds electrical. I think I pin pointed it to the driver side under the intake manifold, maybe something in there, I noticed a box by the throttle body. Also I tried to start the car in this state and it would not START!!! Engine turned over, but no start, just starter turning.

So I disconnected the battery so it would not drain it. Went back and reconnected the battery after about 5 minutes and everything normal. car started up etc. No warning lights on when I shut the car off this time, etc. Everything as it should.

SO MY QUESTION IS; what does this sound like is going out. Any techs know what this might be so I can refer this to my independent and /or change myself.

Thanks for reading my long post, but I hope all the info will lead to an answer.

Floyd in Arizona

called the Mercedes emergency service guy out. He said the alarm system in the car and the electronics in the key had gotten out of sync. His solution was to have me hold the button down on the key for several seconds. Problem never came back.

Was your Benz a 1997?

Yes, a 97' E320

Friend,
Due to the fact that some systems remained energized with the key out, the vehicle's "k40" relay module may be sticking. That module is nestled under the module box cover near the right hood hinge. The noise you heard was most likely the throttle actuator motor.
dpk

Thanks, that sounds exactly what happened. The buzzing was coming from the intake/throttle body area. Is the module a DIY item or do you think I need to take to the dealer?

thanks for the reply I appreciate the help. My local independent was going to change the ignition and/or lube it to cure problem.


Floyd