1) Connect the scan tool.
2) Power up the scan tool. Does the scan tool power up?
Yes
=>Go to TCCM communication verification.
No
Go to Scan tool does not power up.
Refer to "51.Engine Control 1A.Troubleshooting(RZ4E-TC) Scan tool does not power up".
Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) Scan tool does not power up".
Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 with DPD) Scan tool does not power up".
1) Check the communication status with the TCCM using the scan tool. Is communication with the TCCM established?
Yes
Go to Intermittent conditions of transfer case control system.
Refer to "204.Driveline, Axle 17D.Symptom intermittent conditions of transfer case control system".
No
1) Inspect for poor connections at the DLC (pins 6 and 14 of C19). Is the connection status normal?
Refer to "LHD DLC" in the ETM (wiring diagram). (Open using the ETM viewer.).
Refer to "RHD DLC" in the ETM (wiring diagram). (Open using the ETM viewer.).
Yes
=>Go to TCCM harness connector inspection.
No
Repair the connections as necessary.
1) Turn OFF the ignition switch.
2) Inspect for poor connections at the TCCM harness connector (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.
1) Inspect for a blown out 4WD 10A fuse. Is the result normal?
Yes
=>Go to Inspection for open circuit in ignition power supply circuit.
No
Replace the fuse. If the fuse blows out again, repair the short to ground in the circuits relating to the 4WD 10A fuse.
1) Turn OFF the ignition switch.
2) Disconnect the TCCM harness connector (C15).
3) Connect a test lamp between the ignition power supply circuit (pin 1 of C15) 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. Does the test lamp illuminate?
Yes
=>Go to Inspection for open circuit in ground circuit.
No
Repair the open circuit or high resistance in the ignition power supply circuit between the 4WD 10A fuse and the TCCM (pin 1 of C15).
1) Connect a test lamp between the ignition power supply circuit and the ground circuit (pins 1, 14, and 15 of C15).
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) Turn ON the ignition switch. Does the test lamp illuminate?
Yes
=>Go to TCCM ground inspection.
No
Repair the open circuit or high resistance in the ground circuit between the TCCM (pins 14 and 15 of C15) and the body ground.
1) Inspect the TCCM ground section for corrosion or improper installation. Is the result normal?
Yes
=>Go to Inspection for open circuit and short circuit in CAN circuit.
No
Repair the ground point as necessary.
1) Inspect for poor connections at the CAN circuit junction connector between the TCCM (pins 6 and 18 of C15) and the DLC (pins 6 and 14 of C19). Is the connection status normal?
2) Inspect the CAN High circuit and the CAN Low circuit between the TCCM (pins 6 and 18 of C15) and the DLC (pins 6 and 14 of C19) for the following. Is the result normal?
Refer to "LHD Controller Area Network (Except Central Gateway C/U)" in the ETM (wiring diagram). (Open using the ETM viewer.).
Refer to "RHD Controller Area Network (Except Central Gateway C/U)" in the ETM (wiring diagram). (Open using the ETM viewer.).
3) Are all of the results normal?
Yes
No
Repair the circuit or connection 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) Turn OFF the ignition switch.
2) Reconnect the disconnected harness connectors.
3) Turn ON the ignition switch.
4) Check the communication status with the TCCM using the scan tool. Is communication with the TCCM established?
Yes
The system is normal.
No