Instrument Cluster Description and Operation: Tachometer

The IPC displays the engine speed as determined by the BCM via a class 2 message. The PCM determines the engine speed and sends a CAN serial data message to the BCM indicating the engine speed. The tachometer will default to 0 RPM if:

• The PCM detects a malfunction in the engine speed sensor circuit.
• The BCM detects a loss of CAN communications with the PCM.
• The IPC detects a loss of class 2 communications with the BCM.