Mercedes diagnostic question
 

I have a MB S-class and within the past week, various warning lights would come on. For example, today when I was on the freeway:

- The CEL, low oil light, ASR, and exterior lamp warning lights came on.
- The tach went to zero RPM but car still moving and can still drive / accelerate
- engine temp went to zero. (not really but on the gauge).
- car felt immediately sluggish - cannot accelerate fast. downshift is hesitant.
- Oil pressure gauge, speedo and fuel gauge continue to work fine.

If I turn the car off and immediately back on - everything goes away. This happened a few times - all at the same time. I feel a slight thump like a loss of power upon occurence. It almost feels like the car just goes into limp mode - I cannot explain the reasoning behind the lights.

Any insights you could share on where to start with the diagnosiss would be really appreciated.

thanks

Uh... Mercedes SL Class - Mercedes Forum - Mercedes Benz Enthusiast Forums

Seriously, tho' check your battery connection to make sure it's tight and not corroded. Sounds like a wonky electrical connection problem.

Failing that, possibly bad alternator is overcharging.

Or... could be a bad ECU.