The speedometer doesn't work
 

Hello!
The speedo on my fathers 2012 W212 doesn't work. Right know it's starts at about 290km/h. The thing is that it keeps on moving when you are driving. It happened when I was overtaking another car at about 130km/h. When slowing down the speedo wouldn't go back and it just kept in showing the wrong speed.

Been at the mechanics who couldn't figure out any faults, no errors were shown in the computer.

Any ideas?

So I noticed today. If I go speeds above 147 the speedo will forget where 0 is and think that 147 on the speedo is 0. So when driving 50 the speedo will show 197..

Any ideas?

I seen some ppl with faulty speedos on this forum , which was replaced later. I would assume u need a new one too. Or maybe reset will help.. which i doubt

you may need a new cluster and a star to tie it up to your car. not a cheap fix. goodluck.

Thanks for the answers! Well ****, new speedo :/

How do I reset the car? Disconnect the battery's?

Yep , try disconnecting the battery for a few mins. If it does nothing , most likely the speedo itself

will do, it's worth a try. Thanks!

Did you ever fix this? I'm having the same issue in my 14 w218. When I go above 90 mph, the speedo gets stuck, and then gets lost completely and wanders. The dealer reset it, but it keeps happening. On restart, it sometimes resets to 0 and works. But it's almost always repeatable at around 90 mph.

It solves it self when its turned off sometimes... Right now it's working fine... :/

So, the delears shop forman determined that it was a bad instrument cluster and that it needed to be replaced. Hopefully that solves it.