Speedometer and/or Odometer Inaccurate or Inoperative

Speedometer and/or Odometer Inaccurate or Inoperative

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.



Circuit/System Description

The instrument panel cluster (IPC) displays the vehicle speed based on information from the body control module (BCM). The 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 the serial data message from the BCM.


Reference Information
Schematic Reference

Instrument Cluster Schematics (Instrument Cluster Schematics)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Instrument Cluster Description and Operation (Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning)


Circuit/System Testing

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



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.



Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.


Control Module References (Programming and Relearning) for IPC replacement, setup, and programming