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.