This speedometer is not the simple, reliable spring-loaded mechanical pointer used in older cars. It is a computer-controlled stepper motor that is placed in the desired position by pulsing four coils with voltage. Two things that could cause this condition are turning the ignition switch off while at highway speed, and spinning on ice, then suddenly hitting the brakes. Once the pointer goes more than half way, the computer tries to pulse it back to zero, and the fastest way there is to go higher and all the way around. It's at zero now, but on the wrong side of the stop.
First, try driving at a speed more than half the maximum shown on the speedometer face. The computer should eventually try to position the pointer in the correct position, then it will follow the commands back down to zero normally as you slow down. The pointer always looks for the shortest distance to the desired point. As long as it's trying to go higher than zero, it will remain stuck. You need to make it want to go lower than maximum, and the shortest way is if you're going more than half the maximum speedometer value.
If that fails, the technicians at the dealership can use their hand-held computer to access the instrument cluster and run the gauges up and down. Eventually the pointer will catch up to the pulsing coils and follow the commands back down to zero.
In the rare event that doesn't work, the cover of the cluster will need to be removed and the pointer physically repositioned. It's possible it is stuck on something.
Tuesday, March 24th, 2009 AT 7:44 PM