Service Indicator Always On. GMC Truck Yukon

For 1990-2009 cars only

Makes 🢒 GMC_Truck 🢒 2003 🢒 Yukon - 4WD 🢒 Body and Accessories 🢒 Instrument Panel, Gages, and Console 🢒 Service Indicator Always On

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 by sending the IPC a Class 2 message. This indicator may be controlled with the scan tool using the IPC device controls.

Test Description

The number below refers to the step number on the diagnostic table.

This step determines whether the failure is the result of a malfunctioning transfer case shift control module or the IPC.

Step	Action	Yes	No
Schematic Reference: Transfer Case Control Schematics Connector End View Reference: Transfer Case Control Connector End Views
1	Did you perform the Diagnostic System Check - Transfer Case?	Go to Step 2	Go to Diagnostic System Check - Transfer Case
2	In the IPC Data List, check the Service 4WD input/output. Is the Service 4WD indicator commanded ON?	Go to Step 3	Go to Step 4
3	Replace the transfer case shift control module. Refer to Transfer Case Shift Control Module Replacement . Did you complete the repair?	Go to Step 5	--
4	Replace the instrument panel cluster. Refer to Instrument Cluster Replacement in Instrument Panel, Gages, and Console. Did you complete the repair?	Go to Step 5	--
5	Use the scan tool in order to clear the DTCs. Operate the vehicle within the Conditions for allowing the symptom to occur. Does the symptom occur?	Go to Step 1	System OK