Inspection Procedure 3: The Cruise Control is Cancelled Although The Switch is not Operated During The ACC System Operation.


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 - Troubleshooting ).
  • Whenever the ECU is replaced, ensure that the CAN bus lines are normal.
  • When the ACC/FCM-ECU is replaced, calibrate the radar (refer to ).

COMMENTS ON TROUBLE SYMPTOM


A malfunction is detected while the ACC system is activated.

PROBABLE CAUSES



DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnostics.
Use M.U.T.-III to perform the CAN bus diagnosis.

Q. Is the check result normal?
Go to Step 2.
Repair the CAN bus lines (Refer to GROUP 54C - Troubleshooting ). On completion, go to Step 2.

STEP 2. Check whether the diagnosis code is set.

Q. Is diagnosis code set?
Troubleshoot the ACC system diagnosis code (Refer to ).
Go to Step 3.

STEP 3. Use M.U.T.-III to confirm a diagnosis code of other systems.
Check if the diagnosis code is set in the engine-ECU (Refer to GROUP 13B - Troubleshooting, Diagnosis Function) <6B3> or (Refer to GROUP 13C - Troubleshooting, Diagnosis Function) <4N1>.

Q. Is the diagnosis code set?
Troubleshoot the engine-ECU diagnosis code (Refer to GROUP 13B - Troubleshooting, Inspection Chart for Diagnosis Code) <6B3> or (Refer to GROUP 13C - Troubleshooting, Inspection Chart for Diagnosis Code) <4N1>.
Go to Step 4.

STEP 4. Use M.U.T.-III to confirm a diagnosis code of other systems.
Check if the diagnosis code is set in the cruise control system (Refer to GROUP 17 - Cruise Control system, Troubleshooting, Diagnosis Function).

Q. Is the diagnosis code set?
Troubleshoot the cruise control system diagnosis code (Refer to GROUP 17 - Cruise Control system, Troubleshooting, Diagnosis Code Chart).
Go to Step 5.

STEP 5. Use M.U.T.-III to confirm a diagnosis code of other systems.
Check if the diagnosis code is set in the ASTC-ECU (Refer to GROUP 35C - Troubleshooting <ASTC-ECU>, Diagnosis Function).

Q. Is the diagnosis code set?
Troubleshoot the ASTC-ECU diagnosis code (Refer to GROUP 35C - Troubleshooting <ASTC-ECU>, Diagnosis Code Chart).
Go to Step 6.

STEP 6. Check the other symptom.
The system should be turned ON when the cruise control switch is operated.

Q. Is the system turned ON by operating the cruise control switch?
Go to Step 7.
Refer to GROUP 17 - Cruise Control system, Troubleshooting, Inspection Procedure 9: When the cruise control switch is operated, the system is not turned on.

STEP 7. Check the cruise control switch.
Refer to .

Q. Is the check result normal?
Go to Step 8.
Replace the cruise control switch (Refer to ).

STEP 8. Check the symptom.
Drive the vehicle for approximately 3 minutes.

Q. Is the cruise control cancelled?
Replace the ACC/FCM-ECU (Refer to ).
It can be assumed that this malfunction is intermittent (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points, How to Cope with Intermittent Malfunction).