Diagnostic Aids

By manipulating the harnesses at the various connectors it is often possible to isolate the cause of the circuit interruption. This harness can then be removed and repaired. Inspect for any damage to the harness, which could cause an intermittent open or short to earth or backed out terminals at the instrument cluster connectors, broken connector locks, improperly formed or damaged terminals. The multimeter allows continuity of the wiring harness circuit 894 to be checked.

DTC 21 - TRIP COMPUTER SWITCH VOLTAGE LOW

Step	Action	Value(s)	Yes	No
1	Did you perform the Instrument Cluster Diagnostic System Check?	-	Go to Step 2	Go to Diagnostic System Check - Instrument Cluster
2	Install a scan tool. Turn the ignition ON, with the engine OFF. Can Tech 2 communicate with the body control module (BCM)?	-	Go to Step 3	Go to Diagnostic Starting Point - Body Control System in Body Control System
3	Inspect the switch for obvious signs of damage. Is damage present?	-	Go to Step 4	Go to Step 5
4	Replace the trip computer switch. Refer to Driver Information Center Switch Replacement . Did you complete the repair?	-	Go to Step 7	-
5	Remove the instrument cluster. Connect an ohmmeter between the instrument cluster C3 mode circuit and a known good ground. Is value as specified?	Less than 1 Ω	Go to Step 6	Go to Step 7
6	Repair short to ground in the trip computer mode circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?	-	Go to Step 7	-
7	Use the scan tool in order to clear the DTCs. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text. Does the DTC reset?	-	Go to Step 2	System OK