Tachometer: Description and Operation

Tachometer
The IPC displays the engine speed based on information from the engine speed sensor. 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 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.