Operation CHARM: Car repair manuals for everyone.

Speedometer Head: Testing and Inspection




1. Using a scan-tool, inspect the speedometer for tolerance and check for the operation of the odometer.

NOTE: It should be noted that the excessive tire wear and tire over or under-inflation will cause indication errors.




2. Check the speedometer for pointer fluctuation and abnormal noise.

NOTE: Pointer fluctuations can be caused by a faulty reed switch.