[Previous][Next]
DTC No.C121A: Steering Wheel Sensor Initialization
 
 
caution
  • If there is any problem in the CAN bus lines, an incorrect DTC 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 (Refer to GROUP 35C - On-vehicle Service ), and reset the steering wheel sensor correction amount stored in the AWD-ECU. (Item No. 1: SAS adjusted value ).
 
 
OPERATION
Steering wheel sensor stores the neutral position learned by the scan tool (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.
 
 
DTC SET CONDITION
This DTC is set when the abnormality below is detected:
  • The steering wheel sensor has not learned the neutral position
 
 
TROUBLESHOOTING HINTS
  • Steering wheel sensor neutral point not learned
  • Malfunction of steering wheel sensor
  • Malfunction of AWD-ECU

 
 
DIAGNOSIS
STEP 1. Scan tool (M.U.T.-III) CAN bus diagnostics.
(1)
cautionTo prevent damage to scan tool (M.U.T.-III), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-III).
Connect scan tool (M.U.T.-III). Refer to "How to connect the Scan Tool (M.U.T.-III) ."
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Is the check result normal?
Go to Step 3.
Repair the CAN bus lines (Refer to GROUP 54C - Troubleshooting ). After repairing the CAN bus line, go to Step 2.
 
STEP 2. Check whether the DTC is set again.
Is DTC No.C121A set?
Go to Step 3.
This diagnosis is complete.
 
STEP 3. Steering wheel sensor calibration.
Perform calibration of the steering wheel sensor (Refer to GROUP 35C - On-vehicle Service ).
Has the calibration succeeded?
Go to Step 4.
Replace the steering wheel sensor (Refer to GROUP 35C - Steering Wheel Sensor ). Then, go to Step 4.
 
STEP 4. Check whether the DTC is set again.
Is DTC No.C121A set?
Replace the AWD-ECU (Refer to ). Then, go to Step 5.
Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).
 
STEP 5. Check whether the DTC is set again.
Is DTC No.C121A set?
Return to Step 1.
This diagnosis is complete.