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 |
DTC Descriptors
DTC B0654: Engine Speed Signal Range/PerformanceCircuit/System Description
The instrument panel cluster (IPC) receives engine speed data from the ECM via the serial data circuit for display in the IPC. The ECM sends the engine speed information to the steering column control module (SCCM) via the serial data circuit. The SCCM sends the engine speed information to the IPC via the serial data circuit. The IPC uses the engine speed data to display the tachometer.
Conditions for Running the DTC
| • | The engine is running. |
| • | The ignition voltage is between 9-18 volts. |
Conditions for Setting the DTC
| • | The ECM detects that the engine speed information is invalid. |
| • | The above condition must be present for a minimum of 8 seconds. |
Action Taken When the DTC Sets
The ECM records the operating conditions at the time the diagnostic fails. The ECM displays the failure information in the Failure Records on the scan tool.
Conditions for Clearing the DTC
| • | The DTC becomes history when the conditions for setting the DTC are no longer present. |
| • | The history DTC clears after 40 malfunction-free warm-up cycles. |
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
- Ignition ON and the scan tool installed, perform the IPC Engine Speed Control Test from the ECU Control menu. Verify that the tachometer pointer moves from the minimum value to the maximum value as commanded.
- Verify that the tachometer value matches the scan tool Engine Speed parameter in the ECM Engine Data List.
| ⇒ | If the tachometer does not perform the Engine Speed Control Test, replace the IPC. |
| ⇒ | If the tachometer is incorrect, test or replace the IPC. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for the IPC replacement, setup and programming.
