I need some help on my '97 E320. The speedometer reads 40MPH at a full stop. It seems to carry this fast reading when driving. When doing a true 40MPH, it reads 80MPH, etc. the problem began a few months ago with the speedo reading just a few MPH at rest.

Any suggestions?? Is this a pure electronic unit?? Is the speedo replaceable by itself, or is it an intergral part of the entire gauge cluster??

Thanks for any help!!

 

the instrument cluster can only be replaced as a whole unit, and no individual parts available except for the miniature bulb, and circuit board. some dealers do the chop-chop and might be available too.

yes it is electronic, it gets the signal from the front left wheel speed sensor via your BAS/ESP or ABS control module. the alternate reversing of polarity makes it run.

i think the problem was because the needle got loosely mounted? in that case, you can put it back to zero and firmly press it in again.

 

I'll give the needle a look and see if that works. Thanks!!!!