Component Tests and General Diagnostics

DIFF LOCK Indicator Lamp Circuit Check

Description

The DIFF LOCK indicator lamp has power available to it any time the ignition switch is in the ON or START position. The differential lock control unit supplies ground to activate the DIFF LOCK indicator lamp. The DIFF LOCK indicator lamp will go through a prove out at initial key ON. The DIFF LOCK will flash while the differential lock system is activating or while waiting for conditions to be met to activate. Once the differential lock has been engaged, the DIFF LOCK indicator lamp will remain ON. For more information about the DIFF LOCK indicator lamp, refer to the Owner's Manual.

Component Function Check

1. CHECK DIFF LOCK INDICATOR LAMP OPERATION

1 Turn the ignition switch ON.
2 Observe the DIFF LOCK indicator lamp.






Does the DIFF LOCK indicator lamp prove out normally?
YES
DIFF LOCK indicator lamp is operating normally.
NO, ALWAYS ON
Perform "DTC check" on differential lock control unit. Refer to [SDT Function (Diff Lock)] Scan Tool Testing and Procedures.
NO, ALWAYS OFF
ERROR! Unknown action!Check DIFF LOCK indicator lamp control circuit. Refer to "Diagnosis Procedure".

Diagnosis Procedure

Regarding Wiring Diagram information, refer to [Differential Lock Control Unit: Wiring Diagram] [1][2]Differential Lock.

1. CHECK DIFFERENTIAL LOCK CONTROL UNIT POWER AND GROUND SUPPLY

Check the differential lock control unit power and ground supply. Refer to [P1833 Initial Start] P1833.

Is the inspection result normal?
YES
GO TO 2.
NO
Repair or replace malfunctioning component.

2. CHECK HARNESS BETWEEN DIFFERENTIAL LOCK CONTROL UNIT AND COMBINATION METER

1 Turn ignition switch OFF.





2 Disconnect differential lock control unit harness connector and combination meter harness connector.
3 Check continuity between differential lock control unit harness connector M70 (A) terminal 21 and combination meter harness connector M24 (B) terminal 25.






4 Check continuity between differential lock control unit harness connector M70 (A) terminal 21 and ground.






Is the inspection result normal?
YES
Replace combination meter. Refer to [Combination Meter: Removal and Installation] Service and Repair.
NO
Repair harness or connector.