[ Model - ECLIPSE CROSS / Year - 2018 ]
2018 / ECLIPSE CROSS / EC - Workshop Manual
35 -SERVICE BRAKES > 35C-ACTIVE STABILITY CONTROL SYSTEM (ASC) > TROUBLESHOOTING<ASC-ECU><ASC-ECU> > DIAGNOSIS CODE PROCEDURES > CODE NO. C121A: ABNORMALITY IN STEERING WHEEL SENSOR INITIALISATION
Code No. C121A SAS Initialisation
 
 
caution
  • If there is any problem in the CAN bus lines, an incorrect diagnosis code may be set. Prior to this diagnosis, diagnose the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics Table ).
  • Whenever ECU is replaced, ensure that the CAN bus lines are normal.
 
 
OPERATION
Steering wheel sensor stores the neutral position learned by M.U.T.-IIISE. When the neutral position has not been stored in the steering wheel sensor yet, the steering wheel sensor outputs the signal indicating that it does not have neutral position.
 
 
 
DIAGNOSIS CODE SET CONDITIONS
This diagnosis code is set when ASC-ECU detects that the steering wheel sensor has not learned the neutral position yet.
 
 
 
PROBABLE CAUSES
  • Neutral position of steering wheel sensor not learned
  • Steering wheel sensor malfunction
  • ASC-ECU malfunction
 
 
 
 
DIAGNOSIS PROCEDURE
STEP 1. M.U.T.-IIISE CAN bus diagnostics
Use M.U.T.-IIISE to diagnose the CAN bus lines.
Is the check result normal?
Go to Step 3.
Repair the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics Table ). On completion, go to Step 2.
 
STEP 2. Diagnosis code recheck after resetting CAN bus lines
Is diagnosis code No.C121A set?
Go to Step 3.
This diagnosis is complete.
 
STEP 3. Check how steering wheel sensor is installed.
Check that the steering wheel sensor is installed correctly (Refer to ).
Is the check result normal?
Go to Step 4.
Install the steering wheel sensor correctly (Refer to ).
 
STEP 4. Steering wheel sensor calibration
Perform calibration of steering wheel sensor (Refer to ).
Has the calibration succeeded?
Go to Step 5.
After the steering wheel sensor is replaced, perform the steering wheel sensor calibration to make ASC-ECU learn the neutral point again (Refer to ).
 
STEP 5. Check whether the diagnosis code is set again.
Erase the diagnosis code.
Is diagnosis code No.C121A set?
Replace the hydraulic unit (integrated with ASC-ECU) (Refer to ).
This diagnosis is complete.