Code No. C145D: Wiring harness and coupling coil open circuit failure


caution If there is any problem in the CAN bus lines, an incorrect diagnosis code may be set. Prior to this diagnosis, always diagnose the CAN bus lines.

OPERATION



DIAGNOSIS CODE SET CONDITIONS




  • Sets the specified current command value to the electronic control coupling solenoid
  • Drive current value of the electronic control coupling solenoid: Deviated from the normal current range

PROBABLE CAUSES


Current trouble
  • Open circuit inside the electronic control coupling solenoid
  • Damaged wiring harness and connectors

    • Short to earth or open circuit between the battery and 4WD-ECU
    • Short to power supply or open circuit between 4WD-ECU and the electronic control coupling solenoid
    • Short to earth between 4WD-ECU and the electronic control coupling solenoid
  • 4WD-ECU internal error
Past trouble
  • Intermittent wiring harness or connector failure
    note For diagnosis procedures, refer to "How to treat past trouble". (Refer to GROUP 00, How to Treat Past Trouble .)
  • Intermittent electronic control coupling failure (solenoid failure)

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnostics
Use M.U.T.-III to diagnose the CAN bus lines.

Q. Is the check result normal?
Go to Step 3.
Repair the CAN bus line. (Refer to GROUP 54C - Troubleshooting .) On completion, go to Step 2.

STEP 2. Check whether the diagnosis code is reset after repairing the CAN bus line.
(1)Erase the diagnosis code.
(2)Turn the ignition switch from the LOCK (OFF) position to the ON position and hold there for 2 seconds.
(3)Use M.U.T.-III to forcibly activate the electronic control coupling from 600 N·m to 730 N·m in 10 N·m steps. (Refer to Actuator Test Table .)
(4)Check if the diagnosis code is set.

Q. Is the diagnosis code No. C145D set?
Go to Step 3.
This diagnosis is complete.

STEP 3. M.U.T.-III data list
Check the following service data. (Refer to .)

  • Item 04: Coupling current command value
  • Item 05: Coupling current monitor value

Q. Is the check result normal?
Replace 4WD-ECU. (Refer to .)
Go to Step 4.

STEP 4. Check the following connector:
Check the connectors below for improper engagement, terminal damage or terminal drawn in the connector case.

  • C-130 4WD-ECU connector
  • D-113 electronic control coupling solenoid connector
  • C-35 intermediate connector

Q. Are the connectors and terminals in good condition?
Go to Step 5.
Repair the connector(s) or terminal(s). Then go to Step 10.

STEP 5. Wiring harness check
Check the wiring harness between the C-130 4WD-ECU connector and the D-113 electronic control coupling solenoid connector for damage or other problem.

Q. Is the wiring harness in good condition?
Go to Step 6.
Repair damage or other problem in the wiring harness. Then go to Step 10.

STEP 6. Resistance measurement between electronic control coupling solenoid connector (coupling side) terminals
Disconnect the D-113 connector, and measure the resistance value between the connector terminals on the electronic control coupling side.
Standard value: 2.2 - 4.0 Ω

Q. Is the measured resistance value within the standard value range?
Go to Step 7.
Replace the electronic control coupling. (Refer to .) Then go to Step 10.

STEP 7. Voltage measurement at the 4WD-ECU connector
(1)Disconnect the C-130 4WD-ECU connector.
(2)Measure the voltage between the C-130 wiring harness side connector terminals No. 3 and No. 10.
OK: Battery voltage

Q. Is the check result normal?
Go to Step 9.
Go to Step 8.

STEP 8. Wiring harness check
note Prior to the wiring harness inspection, check the C-315 ETACS-ECU connector, and repair if necessary.
Check the wiring harness between the C-130 4WD-ECU connector (terminal No. 3) and the C-309 ETACS-ECU connector (terminal No. 1) for damage or other problem.

Q. Is the wiring harness in good condition?
Go to Step 9.
Repair the wiring harness. Then go to Step 10.

STEP 9. Check whether the diagnosis code is reset.
(1)Erase the diagnosis code.
(2)Turn the ignition switch from the LOCK (OFF) position to the ON position and hold there for 2 seconds.
(3)Use M.U.T.-III to forcibly activate the electronic control coupling from 600 N·m to 730 N·m in 10 N·m steps. (Refer to Actuator Test Table .)
(4)Check if the diagnosis code is set.

Q. Is the diagnosis code No. C145D set?
Replace 4WD-ECU. (Refer to .) Then go to Step 10.
The trouble can be an intermittent malfunction. (Refer to GROUP 00 - How to Cope with Intermittent Malfunction .)

STEP 10. Check whether the diagnosis code is reset.
(1)Erase the diagnosis code.
(2)Turn the ignition switch from the LOCK (OFF) position to the ON position and hold there for 2 seconds.
(3)Use M.U.T.-III to forcibly activate the electronic control coupling from 600 N·m to 730 N·m in 10 N·m steps. (Refer to Actuator Test Table .)
(4)Check if the diagnosis code is set.

Q. Is the diagnosis code No. C145D set?
Diagnose again from Step 1.
This diagnosis is complete.