Code No.C1800 ACC Acceleration/Deceleration monitor


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

OPERATION
The ASC-ECU receives target acceleration/deceleration signal via CAN bus lines from the ACC/FCM-ECU.

DIAGNOSIS CODE SET CONDITIONS
The ASC-ECU stores this diagnosis code when the target acceleration/deceleration signal, which is received from the ACC/FCM-ECU, is abnormal.

PROBABLE CAUSES

  • Malfunction of ACC/FCM-ECU
  • Malfunction of ASC-ECU

DIAGNOSIS PROCEDURE

STEP 1. 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 2

STEP 2. 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.C1800 set?
Replace the hydraulic unit (integrated with ASC-ECU) (Refer to ). Then go to Step 3.
This diagnosis is complete.

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.C1800 set?
Return to Step 1.
This diagnosis is complete.