The instrument panel cluster (IPC) displays the engine speed based on the information from the powertrain control module (PCM) (4.2L) or engine control module (ECM) (5.3L). The PCM/ECM converts the data for engine speed to a 2 pulses/engine revolution signal. The IPC uses the engine speed signal circuit from the PCM/ECM in order to calculate the engine speed.

Schematic Reference

Instrument Cluster Schematics

Connector End View Reference

Instrument Panel, Gages, and Console Connector End Views

Description and Operation

Instrument Cluster Description and Operation

Electrical Information Reference

Scan Tool Reference

Ignition ON, using the scan tool, perform the IPC Gauges output control test. All gauges should sweep from their minimum position to their maximum position and return.

1. With the engine running, use a scan tool to compare the engine speed at the PCM/ECM display to the engine speed reported at the IPC display. The engine speed displayed at the IPC should be within +/- 250 RPM of that displayed at the PCM/ECM.

⇒	If the scan tool displayed engine speed are not equal, test for an open/high resistance or short to ground on the engine speed signal circuit. If the circuit tests normal, replace the PCM/ECM.

2. If all circuits test normal, test or replace the IPC.

Control Module References for ECM/PCM and IPC replacement, setup and programming.