Service Four-Wheel Drive Indicator Always On
Service Four-Wheel Drive Indicator Always On
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.
Circuit Description
The service 4WD indicator is located in the instrument panel cluster (IPC) and shares the common power and ground of the IPC. The transfer case shift control module turns ON or OFF the SERVICE 4WD indicator by sending the IPC a class 2 message.
Reference Information
Schematic Reference
Transfer Case Control Schematics (Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector End Views By Name)
Description and Operation
Transfer Case Description and Operation (Description and Operation)
Electrical Information Reference
* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Circuit/System Testing
1. Ignition OFF, disconnect connectors C1 and C2 of the transfer case shift control module.
2. Ignition ON, the Service 4WD indicator on the IPC should be OFF.
• If the Service 4WD indicator is ON, repair or replace the IPC.
• If the Service 4WD indicator is OFF, replace the transfer case shift control module.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Control Module References (Programming and Relearning) for transfer case shift control module replacement, setup, and programming.
* Instrument Cluster Replacement (Instrument Cluster Replacement)