Instrument Panel Cluster (IPC) Description and Operation: Tachometer

The instrument panel cluster (IPC) displays the engine speed as determined by the ECM/PCM via a class 2 message. The tachometer will default to 0 RPM if:

• The engine control module (ECM)/powertrain control module (PCM) detects a malfunction in the engine speed sensor circuit.
• The IPC detects a loss of class 2 communications with the ECM/PCM.