Code No. C1784: FCM switch fixed ON: Diagnosis
WARNING: This page is about a different car, the 2014 Mitsubishi Outlander. However, it is still accessible from the selected car via links, so may be relevant.
- STEP 1. Scan tool (M.U.T.-III) CAN bus diagnostics.
Use scan tool (M.U.T.-III) to perform the CAN bus diagnosis.
Q: Is the check result normal?
- YES: Go to Step 2.
- NO: Repair the CAN bus lines (Refer to CAN COMMUNICATION-RELATED DTC (U-CODE) TABLE ).
- STEP 2. Scan tool (M.U.T.-III) data list for other system
Check the ETACS-ECU system data list.
- FCM ON/OFF switch: OFF
Item No. Item name Normal condition 404 FCM switch OFF - FCM ON/OFF switch: ON
Item No. Item name Normal condition 404 FCM switch ON (the switch being pressed)
Q: Is the check result normal?
- YES: Go to Step 5.
- NO: Go to Step 3.
- FCM ON/OFF switch: OFF
- STEP 3. Check the FCM ON/OFF switch.
Refer to FCM ON/OFF SWITCH CONTINUITY CHECK .
Q: Is the check result normal?
- YES: Go to Step 4.
- NO: Replace the FCM ON/OFF switch.
- STEP 4. Check of short circuit in FCMS line between ETACS-ECU connector and FCM ON/OFF switch connector
Q: Is the check result normal?
- YES: Replace the ETACS-ECU (Refer to ETACS-ECU ).
- NO: Repair the connector(s) or wiring harness.
- STEP 5. Scan tool (M.U.T.-III) data list.
Check the ACC/FCM system data list.
- FCM ON/OFF switch: OFF
Item No. Item name Normal condition 52 FCM switch state OFF - FCM ON/OFF switch: ON
Item No. Item name Normal condition 52 FCM switch state ON (the switch being pressed)
Q: Is the check result normal?
- YES: Intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).
- NO: Replace the ACC/FCM-ECU (Refer to ACC/FCM-ECU ).
- FCM ON/OFF switch: OFF