Code No.U15A5 FCM/LDW/AHB CAN timeout


caution
  • If diagnosis code U15A5 is set in the combination meter, always diagnose the CAN bus lines.
  • Whenever the ECU is replaced, ensure that the communication circuit is normal.

OPERATION


The clearance warning control unit sets diagnosis code No.U15A5 when it cannot receive signals from the FCM/LDW/AHB-ECU.

TROUBLE JUDGEMENT


If the communication with FCM/LDW/AHB-ECU cannot be established for 2500 ms or more.

PROBABLE CAUSES



DIAGNOSIS PROCEDURE


STEP 1. M.U.T.-III CAN bus diagnostics


Use the 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 - Troubleshooting ).

STEP 2. M.U.T.-III other system diagnosis code


Check if the diagnosis code No. U15A5 is set to other ECU.

Q. Is the diagnosis code set?

Go to Step 3.

Go to Step 4.

STEP 3. Check whether the diagnosis code is set again.


Check again if the diagnosis code is set in the clearance warning control unit.
(1)Erase the diagnosis code.
(2)Turn the ignition switch from the "LOCK" (OFF) position to the "ON" position.
(3)Check if the diagnosis code is set.

Q. Is the diagnosis code set?

Replace the FCM/LDW/AHB-ECU (Refer to ).

A poor connection, open circuit, or other intermittent malfunction in the CAN bus line between the clearance warning control unit and the FCM/LDW/AHB-ECU (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction).

STEP 4. Check whether the diagnosis code is set again.


Check again if the diagnosis code is set in the clearance warning control unit.
(1)Erase the diagnosis code.
(2)Turn the ignition switch from the "LOCK" (OFF) position to the "ON" position.
(3)Check if the diagnosis code is set.

Q. Is the diagnosis code set?

Replace the clearance warning control unit (Refer to ).

A poor connection, open circuit, or other intermittent malfunction in the CAN bus line between the clearance warning control unit and the FCM/LDW/AHB-ECU (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction).