Circuit/System Description

The instrument panel cluster (IPC) displays the engine speed based on the engine speed data from the engine control module (ECM) or the powertrain control module (PCM). The ECM/PCM converts the data from the engine speed sensor to a 2 pulses/engine revolution signal. The ECM/PCM sends a GMLAN message to the IPC indicating the engine speed. The IPC displays the engine speed based on the GMLAN serial data message from the ECM/PCM.