1) Observe the DTC information for the rear differential lock control unit with a scan tool. Is a DTC set?
Yes
Go to the applicable DTC diagnosis.
No
=>Go to Rear differential lock indicator light illumination check.
1) Lift up the vehicle.
2) Operate the vehicle with the following conditions met.
4WD models
2WD models
3) Check the rear differential lock indicator light. Does the rear differential lock indicator light illuminate?
Yes
Go to Intermittent conditions of rear differential lock control system.
No
=>Go to Differential Lock Status parameter check.
1) Operate the vehicle under the following conditions.
4WD models
2WD models
2) Observe the Differential Lock Status parameter on the scan tool. Does the Differential Lock Status parameter show Lock?
Yes
=>Go to Rear differential lock control unit harness connector inspection.
No
=>Go to Rear differential lock switch signal input check.
1) Turn ON the ignition switch.
2) Observe the Rear Differential Lock Switch parameter while operating the rear differential lock switch. Does the Rear Differential Lock Switch parameter change when the switch is operated?
Yes
Go to Rear differential does not lock.
Refer to "204.Driveline, Axle 17D.Symptom rear differential does not lock".
No
Go to Rear differential lock switch system check.
Refer to "53.Driveline Control 3A.Troubleshooting(Differential Lock) rear differential lock switch system check".
1) Inspect for poor connections at the rear differential lock control unit harness connector (pins 1 and 9 of C57). Is the connection status normal?
Refer to "LHD Differential Lock" in the ETM (wiring diagram). (Open using the ETM viewer.).
Refer to "RHD Differential Lock" in the ETM (wiring diagram). (Open using the ETM viewer.).
Yes
=>Go to Rear differential lock indicator light illumination follow-up check.
No
Repair the connections as necessary.
1) Reconnect all of the disconnected harness connectors.
2) Clear the DTC with a scan tool.
3) Turn OFF the ignition switch.
4) Operate the vehicle with the following conditions met.
4WD models
2WD models
5) Check the rear differential lock indicator light. Does the rear differential lock indicator light illuminate?
Yes
Go to Diagnostic system check - differential lock controls.
No
=>Go to Rear differential lock control unit replacement.
Note
Refer to "3.Driveline, Axle 3Z.Driveline, Axle Electrical Control rear differential lock control unit removal".
Refer to "3.Driveline, Axle 3Z.Driveline, Axle Electrical Control rear differential lock control unit installation".
Refer to "3.Driveline, Axle 3Z.Driveline, Axle Electrical Control rear differential lock control unit setting".
Procedure completion
1) Reconnect all of the disconnected harness connectors.
2) Clear the DTC with a scan tool.
3) Turn OFF the ignition switch.
4) Operate the vehicle with the following conditions met.
4WD models
2WD models
5) Check the rear differential lock indicator light. Does the rear differential lock indicator light illuminate?
Yes
Go to Diagnostic system check - differential lock controls.
No
=>Go to Rear differential lock indicator light illumination check.