DTC U0102[00] Lost Communications with Transfer Motor Actuator Unit (4WD models)

1. Transfer control system check

Refer to "53.Driveline Control 3A.Troubleshooting(4WD models) diagnostic system check-transfer case controls".

2. TCCM communication verification

1) Check the communication status with the TCCM using the scan tool. Is communication with the TCCM established?

Yes

=>Go to Inspection for open circuit in transfer actuator power supply circuit.

No

Go to Lost communication with the TCCM.

Refer to "53.Driveline Control 3A.Troubleshooting(4WD models) lost communication with the TCCM (models with radar sensor/ stereo camera)".

Refer to "53.Driveline Control 3A.Troubleshooting(4WD models) lost communication with the TCCM (models without radar sensor and stereo camera)".

3. Inspection for open circuit in transfer actuator power supply circuit

1) Turn OFF the ignition switch.

2) Disconnect the transfer actuator harness connector (E38).

3) Connect a test lamp between the ignition power supply circuit (pin 5 of E38) 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 transfer actuator ground circuit.

No

Repair the open circuit or high resistance in the ignition power supply circuit between the 4WD 10A fuse and the transfer actuator (pin 5 of E38). Inspect the 4WD 10A fuse first.

=>Go to Repair verification.

4. Inspection for open circuit in transfer actuator ground circuit

1) Turn OFF the ignition switch.

2) Connect a test lamp between the ignition power supply circuit and the ground circuit (pins 1 and 5 of E38).

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. Does the test lamp illuminate?

Yes

=>Go to Inspection for open circuit and short circuit in CAN circuit.

No

Repair the open circuit or high resistance in the ground circuit between the transfer actuator (pin 1 of E38) and the body ground.

=>Go to Repair verification.

5. Inspection for open circuit and short circuit in CAN circuit

1) Inspect the CAN High circuit and the CAN Low circuit between the TCCM (pins 4 and 16 of C15) and the transfer actuator (pins 2 and 3 of E38) for the following. Is the result normal?

  • Open circuit
  • Short to the battery power supply circuit or short to the ignition power supply circuit
  • Short to ground
  • High resistance

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 Transfer actuator harness connector inspection.

No

Repair the circuit as necessary.

=>Go to Repair verification.

6. Transfer actuator harness connector inspection

1) Inspect for poor connections at the transfer actuator harness connector (pins 2 and 3 of E38). 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 transfer actuator.

Refer to "3.Driveline, Axle 3D.Transfer Case transfer disassembly".

Refer to "3.Driveline, Axle 3D.Transfer Case transfer reassembly".

=>Go to Repair verification.

No

Repair the connections as necessary.

=>Go to Repair verification.

7. Repair verification

1) Clear the DTC with a scan tool.

2) Turn OFF the ignition switch for 30 seconds or more.

3) Start the engine.

4) Operate the vehicle under the conditions for running the DTC.

5) Observe the DTC information with a scan tool.