PCM Controlled Tachometer Diagnosis

Circuit Description
The PCM controls the pulse frequency in relationship to engine RPM, and sends the information class II to the Instrument Cluster.

Diagnostic Aids
For diagnosis of the instrument panel, refer to Instrument Panel, Gauges and Warning Indicators / System Diagnosis. Also check for the following conditions:
^ Poor connection at the PCM or instrument cluster. Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection.
^ Damaged harness. Inspect the wiring harness for damage.