Code No. U113C: Wheel speed sensor data error

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.
Before replacing the ECU, ensure that the communication circuit is normal.

OPERATION

4WD-ECU receives the data (such as ABS sensor signal, ABS operation signal) via the CAN bus lines. If it cannot receive such data, it interrupts the system.

DIAGNOSIS CODE SET CONDITIONS

If the following conditions are met when the system is activated, 4WD-ECU gradually switches the control from 4WD to 2WD, flashes the 4WD/LOCK indicators alternately, and sets the diagnosis code No. U113C.

IG1 voltage: 8 V or more
ABS signal (such as wheel speed signal) cannot be received.
Diagnosis code No.C0120 ABS CAN time-out is not detected.

PROBABLE CAUSES

Current trouble

Wiring harness or connector failure between ASC-ECU and the stop lamp switch
Malfunction of the ABS sensor
Malfunction of the stop lamp switch
ASC-ECU malfunction
4WD-ECU malfunction

Past trouble

Refer to "How to treat past trouble" (GROUP 00 - How to Treat Past Trouble ) for proceeding the diagnostics. Diagnose mainly wiring harness or connector failure in the CAN bus lines between ASC-ECU and each ABS sensor, or between ASC-ECU and the stop lamp switch.

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 2.

	Repair the CAN bus line. (Refer to GROUP 54C - Troubleshooting .) Then go to Step 2.

STEP 2. M.U.T.-III Diagnosis code of other systems

Check the following service data. (Refer to

Item 07: CAN system (ABS/ASC)
Item 16: FL wheel speed sensor
Item 17: FR wheel speed sensor
Item 18: RL wheel speed sensor
Item 19: RR wheel speed sensor

Q. Is the diagnosis code set?

	Troubleshoot the ABS system. (Refer to GROUP 35C - Troubleshooting .)

	Go to Step 3.

STEP 3. 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
C-313, C-317 ETACS-ECU connector

Q. Are the connectors and terminals in good condition?

	Go to Step 4.

	Repair the connector(s) or terminal(s). Then go to Step 6.

STEP 4. Wiring harness check

Check the wiring harness between the C-130 4WD-ECU connector and the C-313 ETACS-ECU connector for damage or other problem.

Q. Is the wiring harness in good condition?

	Go to Step 5.

	Repair damage or other problem in the wiring harness. Then go to Step 6.

STEP 5. 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.

(3)Check if the diagnosis code is set.

Q. Is the diagnosis code No. U113C set?

	Replace 4WD-ECU. (Refer to .) Then go to Step 6.

	A poor connection, open circuit or other intermittent malfunction in the CAN bus lines between ASC-ECU and each ABS sensor, or between ASC-ECU and the stop lamp switch is suspected. (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).

STEP 6. Check whether the diagnosis code is reset.

Q. Is the diagnosis code No. U113C set?

	Diagnose again from Step 1.

	This diagnosis is complete.