Code No. C1784
FCM switch fixed ON
| caution |
- Whenever the ECU is replaced, ensure
that the CAN bus lines are normal.
|
OPERATION
The FCM/LDW/AHB-ECU receives the FCM and Ultrasonic misacceleration
Mitigation System ON/OFF switch signal from the ASC-ECU via CAN communication.
DIAGNOSIS CODE SET CONDITION
This diagnosis code is set when the abnormality below is detected:
- The FCM and Ultrasonic misacceleration Mitigation System ON/OFF
switch remains on for at least one minute.
PROBABLE CAUSES
- Malfunction of the FCM and Ultrasonic misacceleration Mitigation System ON/OFF switch
(Stuck on)
- Malfunction of the ASC-ECU
- Malfunction of the FCM/LDW/AHB-ECU
- Damaged harness wires and connectors
DIAGNOSIS PROCEDURE
STEP 1. M.U.T.-III other system data list.
Check the ASC-ECU data list (Refer to 
).
- When the FCM and Ultrasonic misacceleration Mitigation System ON/OFF
switch is pressed.
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Item No.
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Item name
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Normal condition
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167
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FCM ON/OFF switch
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ON
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|
- When the FCM and Ultrasonic misacceleration Mitigation System ON/OFF
switch is not pressed.
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Item No.
|
Item name
|
Normal condition
|
167
|
FCM ON/OFF switch
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OFF
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|
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 ).
- When the FCM and Ultrasonic misacceleration Mitigation System ON/OFF
switch is pressed.
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Item No.
|
Item name
|
Normal condition
|
25
|
FCM ON/OFF switch
|
ON
|
|
- When the FCM and Ultrasonic misacceleration Mitigation System ON/OFF
switch is not pressed.
|
|
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. Check whether the diagnosis code is set again.
Check again if the diagnosis code is set in the FCM/LDW/AHB-ECU.
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(1)Erase the diagnosis code.
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(2)Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
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(3)Check if diagnosis code is set.
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Q.
Is the diagnosis code set?
Replace the FCM/LDW/AHB-ECU (Refer to ).
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How
to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction).
STEP 4. Check of short to earth 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 the FCM and Ultrasonic misacceleration Mitigation System
ON/OFF switch.
Refer to .
Q.
Is the check result normal?
Go to Step 6.
Replace the FCM and Ultrasonic misacceleration Mitigation System ON/OFF switch
(Refer to ).
STEP 6. M.U.T.-III other system data list.
Check the ASC-ECU data list (Refer to ).
- When the FCM and Ultrasonic misacceleration Mitigation System ON/OFF
switch is pressed.
|
|
Item No.
|
Item name
|
Normal condition
|
167
|
FCM ON/OFF switch
|
ON
|
|
- When the FCM and Ultrasonic misacceleration Mitigation System ON/OFF
switch is not pressed.
|
|
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.