W211 Speedometer over-reading

[idlerider]

The car has been parked up for a few weeks, in cold weather. Now, the speedometer needle is over-reading by about 20mph. With the ignition off, it rested at about 20mph - then it started to return to 0mpg in a series of clicks. Now it returns to zero but still over-reads by between 15-20 mph. Does anyone have a solution?

 

[dry run]

Does it do it on the needle or the digital raedout or both?

 

[A.J.]

Does it do it on the needle or the digital raedout or both?

Will a 2006 have a digital display ?

 

[Blobcat]

Will a 2006 have a digital display ?

Yes, in the middle of the speedo

 

[idlerider]

Does it do it on the needle or the digital raedout or both?

Just the needle.

 

[dry run]

That's annoying! When I had my w211 I always had the display set for the digital speed. It sort of made me dependant on that as i found looking at a speedo (needle) redundant. Unfortunately. I don't know the answer to your origional query, but have you triede disconnecting the battery for a few minutes and basically rebooting the system??? Not an expert

 

[jberks]

It sounds like a simple calibration issue. I'd start with just disconnecting the battery for 20 mins and forcing a reset.

When I stripped ours down (to replace a broken cog) the instructions were to set both needles at their maximum stops before reconnecting and the system would recalibrate from there - which it did. I can't see why that would be any better than a simple battery reset but may be worth a try if that doesn't work.