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 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 2-4 switch harness connector (E39).
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.).
3) Turn ON the ignition switch.
4) Observe the 4WD Switch parameter on the scan tool. Does the 4WD Switch parameter show OFF?
Yes
=>Go to Inspection of 2-4 switch harness connector.
No
=>Go to Inspection for short to ground in 2-4 switch signal circuit.
1) Turn OFF the ignition switch.
2) Disconnect the TCCM harness connector (C15).
3) Inspect the signal circuit between the TCCM (pin 8 of C15) and the 2-4 switch (pin 1 of E39) for a short to ground. 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 for poor connections at the 2-4 switch harness connector (pins 1 of E39). 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
Replace the 2-4 switch.
Refer to "3.Driveline, Axle 3D.Transfer Case transfer disassembly".
Refer to "3.Driveline, Axle 3D.Transfer Case transfer reassembly".
No
Repair the connections as necessary.
1) Inspect for poor connections at the TCCM harness connector (pin 8 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.