Speedometer Head: Testing and Inspection

The complexity of the electronics involved with the Speedometer/Odometer (Instrument Cluster) and the two multiplexed communication networks which are connected to it (vehicle speed information passed to all modules that require it, on both networks), preclude the use of workshop general electrical test equipment. Therefore, reference should be made to the Portable Diagnostic Unit (PDU) User Guide for detailed instructions on testing the speedometer and odometer.

The PDU systematically tests and analyses all functions and the various systems affected by it.

Where a fault is indicated, some basic diagnostic methods may be necessary to confirm that connections are good and that wiring is not damaged, before replacing a component.