Diesel Data: Automotive Repair

Service Indicator Inoperative

Service Indicator Inoperative

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 controls the Service indicator lamp by sending the IPC a Class 2 message. This lamp maybe control with the scan tool using the IPC device controls.

Test Description
The numbers below refer to the step numbers on the diagnostic table.
2. Determines whether the failure is the result of a faulty transfer case shift control module or the IPC.

Service Indicator Inoperative: