Forward Collision Mitigation System (FCM) has been an optional feature on Mitsubishi vehicles since 2014. FCM applies the brakes to avoid a collision with the vehicle, objects, or pedestrians in front.

The Forward Collision Mitigation Systems uses a camera and laser radars mounted at the front of the vehicle to automatically apply the brakes when the vehicle detects a chance of an accident due to a reduction in the distance with the vehicle in front.

FCM is part of the e-Assist suite of Mitsubishi Active Safety Technologies and typically comes along with the Adaptive Cruise Control System and Lane Departure Warning System. When working, it will continuously scan the road ahead and monitor other cars and pedestrians’ movement.

This system will alert the driver with a loud warning sound and flashing dashboard signals in case of a possible collision. If the driver fails to react, the system will gain control over the brakes and stop the vehicle in a controlled manner. FCM can not avoid all accidents. If an accident still happens, FCM will try to minimize the damage.

Possible Problems

  • FCM temporarily not available message showing on the vehicle display
  • Inoperable FCM system, meaning the vehicle will not warn the driver about potential obstructions in front or perform emergency braking if needed.
  • ASC  SYSTEM  SERVICE  REQUIRED  (with DTCs C1800, C1777)

When FCM, ACC, and ASC determine abnormal acceleration, the system may enter “fail−safe” mode, with ACC and FCM becoming inoperative.

Possible Causes

  • Radar interference is caused by heavy rain or snow. Excessive amounts of raindrops or snowflakes in front of the vehicle result in inaccurate radar readings. Without a clear vision of the road ahead, the system will shut itself down as a preventive measure. As soon as the weather conditions improve, the FCM will be back online. Vehicle restart may be required.
  • Foreign objects block the proper radar operation. This can be anything from a thick layer of mud and dirt to leaves or objects stuck at the radars’ protective casing. Removing and washing off debris will solve the issue.
  • Physical damage or misalignment of the radar assembly. This can happen due to a previous collision, a small bump in the parking lot, or after performing other repairs to the vehicle’s front end (i.e., bumper removal).
  • Software issues and glitches can cause issues with this system in certain situations. Checking for upgrades and potential recalls will ensure the vehicle has the latest FCM software version. For example. When driving in a lane with normal traffic flow and the adjacent lane is jammed,    FCM    SERVICE REQUIRED, ACC SERVICE REQUIRED, and ASCSYSTEM  SERVICE  REQUIRED  may be displayed (with DTCs C1802, C1777). The continued presence of objects creates continuous inputs that trigger  FCM  operation. The system determines this as an abnormal signal. The system may enter “fail−safe” with ACC  and  FCM becoming inoperative.


Mitsubishi Motors North America (MMNA) has recalled certain 2018 Mitsubishi Outlander PHEV, Outlander Sport, 2018-2019 Eclipse Cross, and 2017-2018 Outlander vehicles equipped with a Forward Collision Mitigation (FCM).

According to the NHTSA Safety Recall Report, the FCM may apply braking for longer than needed due to incorrect software. The error may occur when a pedestrian is registered as being in front of the vehicle, even after a pedestrian is no longer detected.

If the FCM software activates the brake longer than necessary, the driver may react by applying additional braking. The resulting rapid deceleration of the vehicle has been suspected to increase the risk of a rear-end collision or cause the driver to lose control of the vehicle. Only vehicles equipped with a forwarding Collision Mitigation (FCM) system are affected.

Troubleshoot Mitsubishi FCM Service Required


To find out why the FCM SERVICE REQUIRED has come on, you will need to read the ASC module codes using a Mitsubishi All System Scanner such as YOUCANIC Full System Scanner.

  1. Plugin the scanner in the OBD-II port under the dashboard.
  2. Turn on the ignition.
  3. Turn on the scanner.
  4. Select Mitsubishi, then the correct model. For example, Outlander, Lancer, Mirage, etc.
  5. Scroll to Control Unit
  6. Select the ASC System
  7. Select Read Fault Codes

This will display the fault codes stored in the ASC module, which has disabled the FCM system. Note that the ASC system may need to be updated in some cases, which needs to be completed by the dealer.

Additional Resources

  1. ACC/FCM/ASC WARNING LAMP ILLUMINATION – Technical Service Bulletin –

We hope you find the Mitsubishi Forward Collision Mitigation System (FCM) guide helpful. Check these troubleshooting and repair guides for more help on your Mitsubishi.

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