Instrument Cluster Description & Operation: Tachometer
The instrument panel cluster (IPC) displays the engine speed as determined by the engine control module (ECM). The IPC receives a serial data message from the body control module (BCM) indicating the engine speed. The tachometer will default to 0 RPM if:
- The ECM detects a malfunction in the engine speed sensor circuit.
- The BCM detects a loss of serial data communications with the ECM.
- The IPC detects a loss of serial data communications with the BCM.