Instrument Cluster Description and Operation: Tachometer

The IPC displays the engine speed based on the engine speed signal from the PCM. The IPC receives the engine speed signal from the PCM via a discreet wire. The IPC uses the engine speed signal circuit (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 (2 pulses/engine revolution) exists.