The engine control module (ECM) creates the engine speed signal by pulsing the engine speed signal circuit to ground at a rate of 2 pulses per engine revolution. The instrument panel cluster (IPC) converts the engine speed signal to a tachometer position to indicate the engine speed. The IPC also receives from the ECM a serial data message indicating the engine speed. The IPC uses the serial data engine speed information from the ECM for diagnostic purposes.

Schematic Reference

Instrument Cluster Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

1. Engine ON, verify the scan tool Engine Speed parameter matches the tachometer display.

⇒	If the Engine Speed parameter does not match the tachometer display, test the signal circuit terminal A12 for an open/high resistance.

2. If the circuit tests normal, replace the IPC.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for the IPC replacement, setup, and programming