Code No. U1011: ACC/FCM Parity/Toggle bit error


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 - Troubleshooting ).
  • Whenever ECU is replaced, ensure that the CAN bus lines are normal.
  • When the FCM-ECU is replaced, calibrate the radar (refer to ).
  • When the hydraulic unit assembly (integrated with ASTC-ECU) is replaced, always carry out the calibration of the steering wheel sensor and the G sensor (Refer to ).

OPERATION


FCM-related signals are sent or received to and from between ASTC-ECU and FCM-ECU via CAN bus lines.

DIAGNOSIS CODE SET CONDITIONS


This diagnosis code is set when the ASTC-ECU has detected an abnormal FCM-related signal.

PROBABLE CAUSES



DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnosis
Use the 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 - Troubleshooting ). On completion, go to Step 2.

STEP 2. Diagnosis code recheck after resetting CAN bus lines

Q. Is diagnosis code No. U1011 set?
Go to Step 3.
This diagnosis is complete.

STEP 3. Use M.U.T.-III to confirm a diagnosis code of other systems.
Check if the diagnosis code is set in the FCM-ECU (Refer to ).

Q. Is the diagnosis code set?
Follow the relevant diagnosis code procedure.
Go to Step 4.

STEP 4. Check whether the diagnosis code is set again.
Check again if the diagnosis code is set.
(1)Erase the set diagnosis code.
(2)Ignition switch: "LOCK" (OFF)
(3)Ignition switch: "ON"

Q. Is diagnosis code No. U1101 set?
Replace the hydraulic unit assembly (integrated with ASTC-ECU) (Refer to ).
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).