Instrument Cluster Description and Operation: Tachometer
WARNING: This page is about a different car, the 2009 GMC Sierra, 2009 GMC Cab & Chassis Sierra, 2009 Chevrolet Silverado, and 2009 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The IPC displays the engine speed as determined by the ECM. The IPC receives a serial data message from the ECM indicating the engine speed. The tachometer will default to 0 RPM if:
- The ECM detects a malfunction in the engine speed sensor circuit.
- The IPC detects a loss of serial data communications with the ECM.