Circuit/System Description

The instrument panel cluster (IPC) displays the engine speed based on the information from the engine control module (ECM). The ECM converts the data from the engine speed sensor to a 2 pulses/engine revolution signal. The PCM sends the engine speed information via GMLAN serial data circuit tot he body control module (BCM). The BCM sends the GMLAN message to the IPC in order to control the tachometer gage and display the engine speed.