Code No.C1802 ACC/FCM ECU fail



caution Before replacing the ECU, ensure that the communication circuit is normal.

OPERATION


The ASC-ECU communicates with the ACC/FCM-ECU via CAN bus lines.

DIAGNOSIS CODE SET CONDITIONS


If the ASC-ECU receives an abnormal signal from the ACC/FCM-ECU with the ACC activated, it will store the diagnosis code.

PROBABLE CAUSES



  • Wiring harness or connector failure of CAN bus line
  • Malfunction of ACC/FCM-ECU
  • Malfunction of ASC-ECU

DIAGNOSIS PROCEDURE


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


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 3.

STEP 2. M.U.T.-III Diagnosis code of other system


Use M.U.T.-III to check that the diagnosis code is set by the ACC/FCM-ECU.

Q. Is the diagnosis code set?

Troubleshoot for the relevant diagnosis code. Refer to GROUP 17 - Adaptive Cruise Control System (ACC) .
Go to Step 3.

STEP 3. Check whether the diagnosis code is reset.


(1)Erase the diagnosis code.
(2)Ignition switch "LOCK" (OFF)
(3)Ignition switch "ON"

Q. Is diagnosis code No.C1802 set?

Replace the hydraulic unit (integrated with ASC-ECU) (Refer to ). Then go to Step 4.
This diagnosis is complete.

STEP 4. Check whether the diagnosis code is reset.


(1)Erase the diagnosis code.
(2)Ignition switch "LOCK" (OFF)
(3)Ignition switch "ON"

Q. Is diagnosis code No.C1802 set?

Return to Step 1.
This diagnosis is complete.