Inspection Procedure 2: The FCM cannot be turned on or off when the FCM and Ultrasonic misacceleration Mitigation System ON/OFF switch is operated.


caution
  • Whenever ECU is replaced, ensure that the CAN bus lines are normal.

COMMENTS ON TROUBLE SYMPTOM


If the system is not turned on and off by operating the FCM and Ultrasonic misacceleration Mitigation System ON/OFF switch, the FCM and Ultrasonic misacceleration Mitigation System ON/OFF switch, the ASC-ECU or the FCM/LDW/AHB-ECU may be defective.

PROBABLE CAUSES



DIAGNOSIS PROCEDURE


STEP 1. M.U.T.-III other system data list.


Check the ASC-ECU data list (Refer to ).

Item No.
 Item name
 Normal condition
167
 FCM ON/OFF switch
 ON

Item No.
 Item name
 Normal condition
167
 FCM ON/OFF switch
 OFF
OK: Normal condition is displayed.

Q. Is the check result normal?

Go to Step 2.

Go to Step 4.

STEP 2. M.U.T.-III data list.


Check the input signal (Refer to ).

Item No.
 Item name
 Normal condition
25
 FCM ON/OFF switch
 ON

Item No.
 Item name
 Normal condition
25
 FCM ON/OFF switch
 OFF
OK: Normal condition is displayed.

Q. Is the check result normal?

Go to Step 3.

Replace the FCM/LDW/AHB-ECU (Refer to ).

STEP 3. Retest the system.


Check whether system is turned on and off by operating the FCM and Ultrasonic misacceleration Mitigation System ON/OFF switch.

Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction).

Replace the FCM/LDW/AHB-ECU (Refer to ).

STEP 4. Check of short to earth, and open circuit in FCSW line between ASC-ECU connector and FCM and Ultrasonic misacceleration Mitigation System ON/OFF switch connector.


Q. Is the check result normal?

Go to Step 5.

Repair the connector(s) or wiring harness.

STEP 5. Check of open circuit in FCM SW(S-) line between FCM and Ultrasonic misacceleration Mitigation System ON/OFF switch connector and body earth.


Q. Is the check result normal?

Go to Step 6.

Repair the connector(s) or wiring harness.

STEP 6. Check the FCM and Ultrasonic misacceleration Mitigation System ON/OFF switch.


Refer to .

Q. Is the check result normal?

Go to Step 7.

Replace the FCM and Ultrasonic misacceleration Mitigation System ON/OFF switch (Refer to ).

STEP 7. M.U.T.-III other system data list.


Check the ASC-ECU data list (Refer to ).

Item No.
 Item name
 Normal condition
167
 FCM ON/OFF switch
 ON

Item No.
 Item name
 Normal condition
167
 FCM ON/OFF switch
 OFF
OK: Normal condition is displayed.

Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction).

Replace the ASC-ECU.