Code No. C123B: Prolonged operation of ASC


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, Trouble code diagnosis ).
  • Whenever ECU is replaced, ensure that the CAN bus lines are normal.
  • Do not drop or shock the G and yaw rate sensor.
  • When the G and yaw rate sensor is replaced, always carry out calibration to make ASC-ECU learn the neutral point (Refer to ).
  • When the hydraulic unit (integrated with ASC-ECU) is replaced, always carry out the calibration of the steering wheel sensor, the G and yaw rate sensor and brake fluid pressure sensor (Refer to , and ).

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.

DIAGNOSIS CODE SET CONDITIONS
This diagnosis code is set when ASC operates for a prolonged period.
note This diagnosis code may be set when the vehicle runs on a slippery or rough road.

PROBABLE CAUSES

  • Malfunction of wheel speed sensor
  • Steering wheel sensor malfunction
  • G and yaw rate sensor malfunction
  • Improper installation of wheel speed sensor, steering wheel sensor, or G and yaw rate sensor
  • ASC-ECU malfunction

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnosis
Use M.U.T.-III to diagnose the CAN bus lines.

Q. Is the check result normal?
Go to Step 3.
Repair the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnosis table ). On completion, go to Step 2.

STEP 2. Diagnosis code recheck after resetting CAN bus lines

Q. Is diagnosis code No.123B set?
Go to Step 3.
This diagnosis is complete.

STEP 3. M.U.T.-III diagnosis code
Check that the diagnosis codes 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.

Q. Are the diagnosis codes 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 relevant diagnosis codes, and then go to Step 5.
Go to Step 4.

STEP 4. Check whether the diagnosis code is reset.

Q. Is diagnosis code No.123B set?
Replace the ASC-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 diagnosis code is reset.

Q. Is diagnosis code No.123B set?
Return to Step 1.
This diagnosis is complete.