Speedometer recalibrates zeropoint

[Duramax_Sweden]

Hi,

my speedometer seems to recalibrate the zeropoint to anywhere between 10 to 30 mph once in a while... When it happens, the speedometer doesn't go all the way down to 0, it sticks at say 15 mph. When I drive it works fine, but it keeps showing +15 mph, 45 when I'm doing 30 and so on. Then after some time it works fine until the next time this happens.

 

Does anyone have any ideas or is there anyone who has had the same problem? Could it be the speedometer itself, or some sensor somewhere?

The truck is imported to Sweden, so the normal warranty isn't valid.

[SnakeEyeSS]

thats wierd, may be a bad sensore, may be a faulty cable... I'm not sure