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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.

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

PROBABLE CAUSES

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

DIAGNOSIS

STEP 1. Scan tool (M.U.T.-III) CAN bus diagnostics
Use scan tool (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. Scan tool (M.U.T.-III) DTC of other system
Use scan tool (M.U.T.-III) to check that the DTC is stored in the ACC/FCM-ECU.

Q. Is the DTC stored?
Troubleshoot for the relevant DTC. Refer to GROUP 17 - Adaptive Cruise Control System (ACC) .
Go to Step 3.

STEP 3. Check whether the DTC is stored again.
(1)Erase the DTC.
(2)Ignition switch "LOCK" (OFF)
(3)Ignition switch "ON"

Q. Is DTC No.C1802 stored?
Replace the ACC/FCM-ECU (Refer to GROUP 17 - Adaptive Cruise Control System (ACC) ). Then go to Step 4.
This diagnosis is complete.

STEP 4. Check whether the DTC is stored again.
(1)Erase the DTC.
(2)Ignition switch "LOCK" (OFF)
(3)Ignition switch "ON"

Q. Is DTC No.C1802 stored?
Return to Step 1.
This diagnosis is complete.