Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Circuit/System Description
The instrument panel cluster (IPC) displays the vehicle speed based on the vehicle speed information from the engine control module (ECM). The ECM sends the vehicle speed information via the serial data circuit to the body control module (BCM). The BCM then sends the information via the serial data circuit to the IPC to order to display the vehicle speed and miles traveled.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Instrument Cluster Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
Important: The drive wheels of the vehicle must be raised and the transmission must be placed in drive or first gear. Refer to Lifting and Jacking the Vehicle.
- Ignition ON, perform the speedometer gage sweep test with the scan tool. Verify that the speedometer gage sweeps from its low to high position.
- Ignition OFF, raise the vehicles drive wheels.
- Engine ON, transmission in drive or 1st gear, verify the scan tool Vehicle Speed Sensor parameter matches the speedometer display.
| ⇒ | If the speedometer gage does not sweep from its low to high position, replace the IPC. |
| ⇒ | If the Vehicle Speed Sensor parameter does not match the speedometer display, replace the IPC. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for IPC replacement, setup, and programming
