STEP 1. Using scan tool (M.U.T.-IIISE), diagnose the CAN bus line.
STEP 2. Check for column switch assembly (integrated with steering wheel sensor) installation.
STEP 3. Steering wheel sensor calibration.
STEP 4. Check whether the DTC is set again.
(1) Turn the ignition switch to the "LOCK" (OFF) position.
(2) Turn the ignition switch to the "ON" position.
Is DTC C121A set?
Replace the hydraulic unit (integrated with ASC-ECU) (Refer to ). This diagnosis is complete.