Refer to "53.Driveline Control 3A.Troubleshooting(4WD models) diagnostic system check-transfer case controls".
1) Connect the scan tool.
2) Turn OFF the ignition switch for 30 seconds or more.
3) Start the engine.
4) Observe the DTC information with a scan tool. Is a DTC set?
Yes
=>Go to 4WD switch 2H signal input check.
No
Go to Intermittent conditions of transfer case control system.
Refer to "204.Driveline, Axle 17D.Symptom intermittent conditions of transfer case control system".
1) Turn OFF the ignition switch.
2) Disconnect the 4WD switch harness connector (B56).
3) Connect a fused jumper wire between the 4WD switch 2H signal circuit (pin 5 of B56) and the body ground.
Refer to "LHD 4WD" in the ETM (wiring diagram). (Open using the ETM viewer.).
Refer to "RHD 4WD" in the ETM (wiring diagram). (Open using the ETM viewer.).
4) Turn ON the ignition switch.
5) Observe the Mode-Switch 2H-port Status parameter on the scan tool. Does the Mode-Switch 2H-port Status parameter show ON?
Yes
=>Go to 4WD switch 4H signal input check.
No
=>Go to Inspection for open circuit in 4WD switch 2H signal circuit.
1) Connect a fused jumper wire between the 4WD switch 4H signal circuit (pin 2 of B56) and the body ground.
Refer to "LHD 4WD" in the ETM (wiring diagram). (Open using the ETM viewer.).
Refer to "RHD 4WD" in the ETM (wiring diagram). (Open using the ETM viewer.).
2) Observe the Mode-Switch 4H-port Status parameter on the scan tool. Does the Mode-Switch 4H-port Status parameter show ON?
Yes
=>Go to Inspection for open circuit in 4WD switch ground circuit.
No
=>Go to Inspection for open circuit in 4WD switch 4H signal circuit.
1) Turn OFF the ignition switch.
2) Disconnect the TCCM harness connector (C15).
3) Inspect the 2H signal circuit between the TCCM (pin 24 of C15) and the 4WD switch (pin 5 of B56) for an open circuit or high resistance. Is the result normal?
Refer to "LHD 4WD" in the ETM (wiring diagram). (Open using the ETM viewer.).
Refer to "RHD 4WD" in the ETM (wiring diagram). (Open using the ETM viewer.).
Yes
=>Go to TCCM harness connector inspection.
No
Repair the circuit as necessary.
1) Turn OFF the ignition switch.
2) Disconnect the TCCM harness connector (C15).
3) Inspect the 4H signal circuit between the TCCM (pin 20 of C15) and the 4WD switch (pin 2 of B56) for an open circuit or high resistance. Is the result normal?
Refer to "LHD 4WD" in the ETM (wiring diagram). (Open using the ETM viewer.).
Refer to "RHD 4WD" in the ETM (wiring diagram). (Open using the ETM viewer.).
Yes
=>Go to TCCM harness connector inspection.
No
Repair the circuit as necessary.
1) Turn OFF the ignition switch.
2) Inspect the ground circuit between the 4WD switch (pin 4 of B56) and the body ground for an open circuit or high resistance. Is the result normal?
Refer to "LHD 4WD" in the ETM (wiring diagram). (Open using the ETM viewer.).
Refer to "RHD 4WD" in the ETM (wiring diagram). (Open using the ETM viewer.).
Yes
=>Go to 4WD switch harness connector inspection.
No
Repair the circuit as necessary.
1) Inspect for poor connections at the 4WD switch harness connector (pins 2, 4, and 5 of B56). Is the connection status normal?
Refer to "LHD 4WD" in the ETM (wiring diagram). (Open using the ETM viewer.).
Refer to "RHD 4WD" in the ETM (wiring diagram). (Open using the ETM viewer.).
Yes
=>Go to 4WD switch inspection.
No
Repair the connections as necessary.
1) Remove the 4WD switch.
Refer to "9.Body, Cab, Accessories 9C.Electrical Control, Entertainment 4WD switch removal".
2) Inspect the 4WD switch. Is the result normal?
Refer to "9.Body, Cab, Accessories 9C.Electrical Control, Entertainment 4WD switch inspection".
Yes
=>Go to TCCM harness connector inspection.
No
Replace the 4WD switch.
Refer to "9.Body, Cab, Accessories 9C.Electrical Control, Entertainment 4WD switch removal".
Refer to "9.Body, Cab, Accessories 9C.Electrical Control, Entertainment 4WD switch installation".
1) Inspect for poor connections at the TCCM harness connector (pins 20 and 24 of C15). Is the connection status normal?
Refer to "LHD 4WD" in the ETM (wiring diagram). (Open using the ETM viewer.).
Refer to "RHD 4WD" in the ETM (wiring diagram). (Open using the ETM viewer.).
Yes
No
Repair the connections as necessary.
Note
Refer to "3.Driveline, Axle 3Z.Driveline, Axle Electrical Control TCCM removal".
Refer to "3.Driveline, Axle 3Z.Driveline, Axle Electrical Control TCCM installation".
Refer to "3.Driveline, Axle 3Z.Driveline, Axle Electrical Control TCCM setting".
Procedure completion
1) Clear the DTC with a scan tool.
2) Turn OFF the ignition switch for 30 seconds or more.
3) Turn ON the ignition switch.
4) Drive the vehicle in 2H, 4H, and 4L modes respectively.
5) Observe the DTC information with a scan tool.