Inspection Procedure 4: When The ACC Distance Switch is Operated, The Distance from Vehicle Travelling in Front cannot be Changed.


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


The ACC/FCM-ECU detects an abnormality or there is an open circuit in the ACC distance switch system.

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. Check the gateway system data list.
Using M.U.T.-III, check the gateway system data list (Refer to GROUP 54C - Troubleshooting <Gateway>, data list reference table).

  • Item No. 20: Steering switch

Q. Is the check result normal?
Go to Step 7.
Go to Step 4.

STEP 4. Check the ACC distance switch.
Refer to .

Q. Is the check result normal?
Go to Step 5.
Replace the cruise control switch (Refer to ).

STEP 5. Check the wiring harness between gateway-ECU connector terminal and clock spring connector terminal steering signal line, between clock spring connector terminal and ACC distance switch connector terminal.
Check the connector and power supply line for short circuit.

Q. Is the check result normal?
Go to Step 6.
Repair the defective connector or the wiring harness.

STEP 6. Check the clock spring.
Refer to GROUP 52B - Driver’s Air Bag Module and Clock Spring, Inspection.

Q. Is the check result normal?
Replace the gateway-ECU (Refer to GROUP 54C - Gateway-ECU).
Replace the clock spring, and install the driver’s air bag module (Refer to GROUP 52B - Driver’s Air Bag Module and Clock Spring).

STEP 7. M.U.T.-III data list.
Check the following data list (Refer to ).

  • Item No. 19: ACC distance switch state

Q. Is the check result normal?
Intermittent malfunction. (Refer to GROUP 00 - How to Cope with Intermittent Malfunction).
Replace the ACC/FCM-ECU (Refer to ).