Inspection Procedure 2: The system cannot be switched on and off when the forward collision mitigation system (FCM) and ultrasonic misacceleration mitigation system ON/OFF switch is operated.


COMMENTS ON TROUBLE SYMPTOM


When the system cannot be switched on and off when the forward collision mitigation system (FCM) and ultrasonic misacceleration mitigation system ON/OFF switch is operated, the forward collision mitigation system (FCM) and ultrasonic misacceleration mitigation system ON/OFF switch, the CAN bus lines, the ASC-ECU, or the clearance warning control unit may have a problem.

PROBABLE CAUSES



DIAGNOSIS PROCEDURE


STEP 1. M.U.T.-III CAN bus diagnostics


Use the M.U.T.-III to diagnose the CAN bus lines.

Q. Is the check result normal?

Go to Step 2.

Repair the CAN bus line (Refer to GROUP 54C - Troubleshooting ).

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


Check the ASC-ECU service data (Refer to GROUP 35C - Data List Reference Table ).

Item No.
 Item name
 Normal condition
167
 FCM ON/OFF switch
 When the switch is operated: ON
When the switch is not operated: OFF
OK: Normal condition is displayed.

Q. Is the check result normal?

Go to Step 3.

Troubleshoot the ASC-ECU (Refer to GROUP 35C - Troubleshooting).

STEP 3. M.U.T.-III data list.


Check the clearance warning control unit service data (Refer to ).

Item No.
 Item name
 Normal condition
18
 FCM OFF SW input signal (CAN)
 When the switch is operated: ON
When the switch is not operated: 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 clearance warning control unit (Refer to ).