Need some advice. My 1997 E320 speedometer reads 40MPH at a dead stop and seems to read that much fast when driving. This fast reading has increased over the past few weeks when it was reading just a bit over zero at a stop and has progressed.

I think this car has an electronic speedo?? No cable?? Anything I can do??

Thanks very much for any assistance or advice.

 

I might be wrong, but I'm pretty sure that if your car has ABS, then the electronic speed sensors on each wheel could be used as your spedometer as well. If that is not the case, then they must monitor the speed off the driveshaft or something. Either way, I think it must be electronic. (Magnets on the rotating part pass over a sensor, which generates an alternating current.)

If I am wrong, would someone please correct me. As far as the reading of over 40mph, I would imagine it would have to do with either the magnets or the wire(s).