Code No. U1004 AS&G CAN time-out


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 .).
  • If diagnosis codes U1004 are set in ASC-ECU, always diagnose the CAN bus line. If there is any fault in the CAN bus lines, an incorrect diagnosis code may be set. In this case, the set diagnosis code is not highly reliable.
  • Before replacing the ECU, ensure that the communication circuit is normal.
  • 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.

OPERATION



DIAGNOSIS CODE SET CONDITION



PROBABLE CAUSES



  • Wiring harness or connector failure of CAN bus line
  • AS&G-ECU malfunction
  • 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 2.
Repair the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics Table .). On completion, go to Step 2.

STEP 2. ETACS-ECU coding data check
Refer to GROUP 00 - Coding List .

Q. Is the check result normal?
Go to Step 3.
Replace the ETACS-ECU (Refer to GROUP 54A - ETACS-ECU .), and then go to Step 6.

STEP 3. M.U.T.-III other system diagnosis code
Use M.U.T.-III to check that other diagnosis code is set in the AS&G-ECU corresponding to the relevant diagnosis.

Q. Is other diagnosis code set?
Troubleshoot for the relevant diagnosis code, and then go to Step 4.
Go to Step 4.

STEP 4. M.U.T.-III diagnosis code
Use M.U.T.-III to check if the same diagnosis code (time-out) is set in the other ECU (CAN-C).

Q. Is any diagnosis code set?
Troubleshoot for the relevant diagnosis code, and then go to Step 5.
Go to Step 5.

STEP 5. Check whether the diagnosis code is reset.
Erase the diagnosis code.

Q. Is Code No. U1004 set?
Replace the hydraulic unit (integrated with ASC-ECU) (Refer to .), and then go to Step 6.
Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunctions .).

STEP 6. Check whether the diagnosis code is reset.
Erase the diagnosis code.

Q. Is diagnosis code No.U1004 set?
Return to Step 1.
This diagnosis is complete.