Speedometer Head: Description and Operation

SPEEDOMETER

The IPC displays the vehicle speed based on the information from the PCM. The PCM converts the data from the vehicle speed sensor to a 4000 pulses/mile signal. The IPC uses the vehicle speed signal circuit (4000 pulses/mile) from the PCM in order to calculate the vehicle speed. If the IPC detects a malfunction in the vehicle speed signal circuit, the IPC uses the class 2 message from the PCM indicating the vehicle speed.