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DTC C123B: System control too long
 
 
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 (Refer to GROUP 54C - CAN Bus Diagnostics Table ).
  • Whenever ECU is replaced, ensure that the CAN bus lines are normal.
 
 
OPERATION
ASC-ECU controls ASC by calculating the data sent from the wheel speed sensor, the steering wheel sensor, and the G and yaw rate sensor.
 
 
 
DTC SET CONDITIONS
This DTC is set when ASC operates for a prolonged period.
noteThis DTC may be set when the vehicle runs on a slippery or rough road.
 
 
 
TROUBLESHOOTING HINTS
  • Steering wheel sensor malfunction
  • Improper installation of steering wheel sensor
  • ASC-ECU malfunction
  • Different steering wheel
  • Wheel alignment not performed
 
 
 
 
DIAGNOSIS
STEP 1. Scan tool (M.U.T.-IIISE) CAN bus diagnostics.
(1)
cautionTo prevent damage to scan tool (M.U.T.-IIISE), always turn off the power supply mode of the electric motor switch before connecting or disconnecting scan tool (M.U.T.-IIISE).
Connect scan tool (M.U.T.-IIISE). Refer to "How to connect the Scan Tool (M.U.T.-IIISE) ."
(2) Turn on the power supply mode of the electric motor switch.
(3) Diagnose the CAN bus line.
(4) Turn off the power supply mode of the electric motor switch.
Is the check result normal?
Go to Step 3.
Repair the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics Table ). After repairing the CAN bus line, go to Step 2.
 
STEP 2. DTC recheck after repairing the CAN bus line.
Is DTC No.C123B set?
Go to Step 3.
This diagnosis is complete.
 
STEP 3. Scan tool (M.U.T.-IIISE) DTC.
Check that DTCs No.C100A, C1015, C1020, C102B, C1011, C101C, C1027, C1032, C1014, C101F, C102A, C1035, C1041, C1042, C1043, C1044, C1219, C2205, C123C, and C2204 are also set.
Are DTCs No.C100A, C1015, C1020, C102B, C1011, C101C, C1027, C1032, C1014, C101F, C102A, C1035, C1041, C1042, C1043, C1044, C1219, C2205, C123C, and C2204 also set?
Carry out the diagnosis for the DTC that is set (Refer to ). Then go to Step 9.
Go to Step 4.
 
STEP 4. Scan tool (M.U.T.-IIISE) data list.
Check the following data list. (Refer to ).
  • Item No. 08: Lateral G sensor
  • Item No. 09: G sensor
  • Item No. 12: Yaw rate sensor
Is the check result normal?
Go to Step 5.
Replace the hydraulic unit (integrated with ASC-ECU) (Refer to ). Then go to Step 9.
 
STEP 5. Check of steering wheel sensor installation status.
Check that the steering wheel sensor is installed correctly.
Is the check result normal?
Go to Step 6.
Install the steering wheel sensor correctly (Refer to ). Then go to Step 6.
 
STEP 6. Wheel alignment check.
Refer to GROUP 33 - On-vehicles service/Front Wheel Alignment Check and Adjustment .
Is the check result normal?
After checking the wheel alignment, perform the calibration of steering wheel sensor to make ASC-ECU relearn the neutral point (Refer to ). Then go to Step 7.
After adjusting the wheel alignment, perform the calibration of steering wheel sensor to make ASC-ECU relearn the neutral point (Refer to ). Then go to Step 7.
 
STEP 7. Scan tool (M.U.T.-IIISE) data list.
Check the following data list (Refer to ).
  • Item No. 11: Steering angle
Is the check result normal?
Go to Step 8.
Replace the steering wheel sensor (Refer to ). Then go to Step 9.
 
STEP 8. Check whether the DTC is set again.
(1) Erase the DTC.
(2) Turn the steering wheel to either right or left at 12 mph (20 km/h) or more.
noteThe ASC warning/operation light and the ASC OFF light may remain on until the vehicle speed reaches approx. 6 mph (10 km/h), then the steering wheel is turned to either right or left.
Is DTC No.C123B set?
Replace the hydraulic unit (integrated with ASC-ECU) (Refer to ). Then go to Step 9.
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/How to Cope with Intermittent Malfunctions ).
 
STEP 9. Check whether the DTC is set again.
(1) Erase the DTC.
(2) Turn the steering wheel to either right or left at 12 mph (20 km/h) or more.
noteThe ASC warning/operation light and the ASC OFF light may remain on until the vehicle speed reaches approx. 6 mph (10 km/h), then the steering wheel is turned to either right or left.
Is DTC No.C123B set?
Return to Step 1.
The procedure is complete.