S-AWC (Super All Wheel Control)

Code No.C121A: Steering Wheel Sensor System (neutral learning abnormality)

CAUTION:

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

- Whenever the ECU is replaced, ensure that the CAN bus lines are normal.

- When the steering wheel sensor is replaced, calibrate the steering wheel sensor Testing and Inspection), and reset the steering wheel sensor correction amount stored in the AWC-ECU. (Item No. 1: SAS adjusted value S-AWC Special Function).

OPERATION

Steering wheel sensor stores the neutral position learned by the M.U.T.-III. When the neutral position has not been learned, the steering wheel sensor outputs the signal indicating that the learning has not been performed.

DIAGNOSTIC TROUBLE CODE SET CONDITIONS

This diagnostic trouble code is set when it is detected that the steering wheel sensor has not learned the neutral position.

PROBABLE CAUSES

- Steering wheel sensor neutral point not learned

- Malfunction of steering wheel sensor

- Malfunction of AWC-ECU

DIAGNOSTIC PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnostics.

Use scan tool to perform the CAN bus diagnosis.

Q. Is the check result normal?

YES Go to Step 3.
NO Repair the CAN bus lines. CAN Bus Diagnostics Chart). After repairing the CAN bus line, go to Step 2.
STEP 2. Check whether the diagnostic trouble code is reset.

Q. Is diagnostic trouble code No.C121A set?

YES Go to Step 3.
NO This diagnosis is complete.
STEP 3. Steering wheel sensor calibration.

Perform calibration of the steering wheel sensor. Testing and Inspection).

Q. Has the calibration succeeded?

YES Go to Step 4.
NO Replace the steering wheel sensor. Service and Repair). Then, go to Step 4.
STEP 4. Check whether the diagnostic trouble code is reset.

Q. Is diagnostic trouble code No.C121A set?

YES Replace the AWC-ECU. (Refer to AWC-ECU Removal and Installation). Then, go to Step 5.
NO Intermittent malfunction. How to Cope With Intermittent Malfunctions).
STEP 5. Check whether the diagnostic trouble code is reset.

Q. Is diagnostic trouble code No.C121A set?

YES Return to Step 1.
NO This diagnosis is complete.