The instrument panel cluster (IPC) displays the vehicle speed based on the information from the body control module (BCM). The engine control module (ECM) sends the vehicle speed signal information via the serial data circuit to the BCM. The BCM sends a serial data message to the IPC indicating the vehicle speed. The IPC displays the vehicle speed based on serial data messages from the BCM.

Schematic Reference

Connector End View Reference

Electrical Information Reference

Scan Tool Reference

Scan Tool Data List

Important: The drive wheels of the vehicle must be raised and the transmission must be placed in drive or first gear.

1. Ignition ON, with the scan tool, perform the IPC Display Test in the IPC Output Controls. Verify that all gage dials move from minimum to the maximum value and back to the gage minimum value.

⇒	If the speedometer does not perform the IPC Displays Test, replace the IPC.

2. Start the engine, raise the vehicle drive wheels and place the transmission in drive or first gear. Verify that the speedometer value matches the scan tool Vehicle Speed parameter in the ECM Engine Data List.

⇒	If the speedometer is incorrect, test or replace the IPC.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

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