Instrument Panel Cluster (IPC) Description and Operation: Tachometer

The IPC displays the engine speed based on information from the PCM. The PCM converts the data from the engine speed sensor to a 2 pulses/engine revolution signal. The IPC uses the engine speed signal circuit of 2 pulses/engine revolution from the PCM in order to calculate the engine speed. The tachometer defaults to 0 rpm if a malfunction in the engine speed signal circuit of 2 pulses/engine revolution exists or if the BCM sends or receives invalid data with the IPC via serial peripheral interface (SPI).