[ 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. C121C: TORQUE REQUEST SIGNAL REJECTION
Code No. C121C Torque Request Signal Denied
 
 
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
ASC-ECU sends the signal to the engine ECU as necessary to decrease the engine output for the ASC system operation.
 
 
 
DIAGNOSIS CODE SET CONDITIONS
This diagnosis code is set when the request for the decrease of output is rejected by the engine ECU.
 
 
 
PROBABLE CAUSES
  • Wrong coding of engine ECU
  • Engine ECU malfunction
  • ASC-ECU malfunction
  • External noise interference
 
 
 
 
DIAGNOSIS PROCEDURE
STEP 1. M.U.T.-IIISE CAN bus diagnosis
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.C121C set?
Go to Step 3.
This diagnosis is complete.
 
STEP 3. M.U.T.-IIISE other system diagnosis code
Use M.U.T.-IIISE to check that the diagnosis code is set in the engine ECU.
Is the diagnosis code set?
Troubleshoot the engine ECU diagnosis code (Refer to GROUP 13A - Troubleshooting/Diagnosis function ).
Go to Step 4.
 
STEP 4. M.U.T.-IIISE diagnosis code
Check that diagnosis code No.C1707 is set in ASC-ECU.
Is diagnosis code No.C1707 set?
Troubleshoot for diagnosis code No.C1707 (Refer to ).
Go to Step 5.
 
STEP 5. M.U.T.-IIISE data list
Check the following service data (Refer to ).
  • Item 13: Allow ESP torque request
Is the check result normal?
Go to Step 6.
Replace the engine ECU (Refer to GROUP 13A - Engine-ECU ).
 
STEP 6. Check whether the diagnosis code is set again.
Erase the diagnosis code.
Is diagnosis code No.C121C set?
Replace the hydraulic unit (integrated with ASC-ECU) (Refer to ).
If the trouble symptom is resolved, an intermittent malfunction such as poorly engaged connector(s) or wiring harness is suspected (Refer to GROUP 00 - How to Use Troubleshooting/How to Cope with Intermittent Malfunctions ).