Understanding Your Car's Forward Collision Mitigation

In the evolving landscape of automotive safety, modern vehicles are equipped with an array of advanced technologies designed to protect occupants and pedestrians alike. Among these innovations, the Forward Collision Mitigation (FCM) system stands out as a crucial guardian, actively working to prevent or significantly lessen the impact of frontal collisions. For owners of Mitsubishi vehicles, understanding the FCM system, its functions, and what to do when it signals a problem, is paramount to maintaining both safety and vehicle integrity.

First introduced as an optional feature on Mitsubishi models from 2014 onwards, the FCM system represents a proactive approach to road safety. Its primary role is to monitor the road ahead and automatically intervene by applying the brakes if it detects an imminent collision with another vehicle, an object, or a pedestrian. This sophisticated system acts as an extra pair of eyes and an immediate responder, designed to complement, not replace, attentive driving.

What Exactly is Forward Collision Mitigation (FCM)?

At its core, the FCM system is an intelligent safety feature integrated into your vehicle's architecture. It constantly scans the environment in front of your car to assess the risk of a potential collision. Utilising a combination of advanced sensors, typically a camera and laser radars meticulously mounted at the front of the vehicle, the system continuously measures the distance and closing speed to objects or vehicles ahead. If this distance rapidly diminishes, indicating a high probability of an accident, the FCM system springs into action.

The system's initial response is designed to alert the driver. You'll typically experience a loud, unmistakable warning sound accompanied by flashing signals on your dashboard. This serves as an urgent prompt for the driver to react. However, if the driver fails to respond adequately or quickly enough, the FCM system is engineered to take control. It will automatically apply the brakes in a controlled manner, aiming to either prevent the collision entirely or, if unavoidable, to significantly minimise the damage and severity of the impact. It's crucial to understand that while highly effective, FCM cannot prevent every single accident; its goal is primarily mitigation.

FCM as Part of Mitsubishi's e-Assist Suite

For Mitsubishi vehicles, the Forward Collision Mitigation system is often a key component of the brand's comprehensive e-Assist suite of Active Safety Technologies. This integrated approach means FCM frequently operates in conjunction with other advanced driver-assistance systems (ADAS), enhancing overall vehicle safety. Common companions to FCM within the e-Assist package include the Adaptive Cruise Control (ACC) System and the Lane Departure Warning (LDW) System. This synergy allows for a more holistic safety net, with systems working in harmony to provide a safer driving experience.

When these systems are fully operational, they continuously monitor various aspects of the driving environment. FCM focuses on frontal obstacles, ACC maintains a safe following distance, and LDW alerts you if you inadvertently drift from your lane. This coordinated effort helps to reduce driver fatigue and enhance situational awareness, contributing to a more relaxed and secure journey.

Understanding Common FCM System Messages and Problems

Like any sophisticated electronic system, the FCM can sometimes encounter issues, leading to warning messages on your vehicle's display. Recognising these messages and understanding their implications is the first step towards resolving any potential problems. Here are some common indicators that your FCM system may require attention:

• "FCM temporarily not available": This message typically indicates that the system is temporarily offline, often due to environmental factors or a minor blockage.
• Inoperable FCM system: This means the system is not functioning, and your vehicle will not provide warnings or emergency braking for potential frontal obstructions.
• "FCM SERVICE REQUIRED": A more serious warning, suggesting a fault that needs professional diagnosis.
• "ACC SERVICE REQUIRED": Often appears concurrently with FCM warnings, as these systems are frequently linked.
• "ASC SYSTEM SERVICE REQUIRED": This message, particularly when accompanied by specific Diagnostic Trouble Codes (DTCs) such as C1800 or C1777, often points to a deeper issue within the vehicle's stability control system that impacts FCM and ACC.

It's important to note that when FCM, ACC, and the Active Stability Control (ASC) system detect abnormal conditions or signals, the system may enter a "fail-safe" mode. In this mode, for safety reasons, ACC and FCM may become inoperative until the underlying issue is addressed.

Potential Causes for FCM System Malfunctions

Several factors can lead to your FCM system displaying warnings or becoming inoperative. These range from simple environmental interferences to more complex hardware or software issues. Understanding these causes can help you determine the appropriate course of action.

Environmental Interference

One of the most common reasons for an "FCM temporarily not available" message is severe weather conditions. Heavy rain or snow can cause significant radar interference. Excessive raindrops or snowflakes directly in front of the vehicle can lead to inaccurate radar readings, effectively blinding the system. As a preventive measure, the system will temporarily shut itself down to avoid erroneous interventions. Typically, as soon as the weather conditions improve and visibility is restored, the FCM system will come back online. A simple vehicle restart may be required to clear the message.

Physical Obstructions and Debris

Foreign objects blocking the radar or camera sensors can also impede proper FCM operation. This can be anything from a thick layer of mud, dirt, or ice to leaves, insects, or even small objects stuck to the protective casing of the sensors. These obstructions prevent the sensors from getting a clear view of the road ahead, leading to system errors. Removing and thoroughly washing off any debris from the sensor areas, usually located in the front bumper or grille, can often resolve this issue promptly.

Physical Damage or Misalignment

The precise calibration of the radar assembly is critical for the FCM system's accuracy. Physical damage or misalignment of these components can severely impact its functionality. This can occur due to a previous minor collision, a small bump received in a car park, or even after performing other repairs to the vehicle's front end, such as bumper removal and reinstallation, if the sensors are not correctly recalibrated. In such cases, professional attention is required to re-align or replace the damaged components.

Software Issues and Recalls

Modern vehicle systems are heavily reliant on software, and the FCM is no exception. Software glitches or outdated versions can sometimes cause intermittent issues or specific malfunctions. Checking for available software upgrades or potential recalls is a vital step in troubleshooting. For instance, Mitsubishi Motors North America (MMNA) previously recalled certain 2018 Mitsubishi Outlander PHEV, Outlander Sport, 2018-2019 Eclipse Cross, and 2017-2018 Outlander vehicles equipped with FCM. This specific recall was due to incorrect software that could cause the FCM to apply braking for longer than necessary, even after a pedestrian was no longer detected. Such an error could lead to rapid deceleration, increasing the risk of a rear-end collision or loss of vehicle control. Ensuring your vehicle has the latest software version is crucial for optimal performance and safety.

Furthermore, specific software logic can sometimes trigger warnings. For example, when driving in a lane with normal traffic flow, and the adjacent lane is heavily jammed, the continuous presence of objects in the adjacent lane can create continuous inputs that the FCM system interprets as an abnormal signal. This can lead to the display of "FCM SERVICE REQUIRED," "ACC SERVICE REQUIRED," and "ASC SYSTEM SERVICE REQUIRED" (often with DTCs C1802, C1777), causing the system to enter "fail-safe" mode.

Troubleshooting "FCM Service Required"

When your Mitsubishi displays an "FCM SERVICE REQUIRED" message, the most effective way to diagnose the underlying problem is by reading the fault codes stored in the vehicle's ASC (Active Stability Control) module. This requires a dedicated Mitsubishi All System Scanner, such as the YOUCANIC Full System Scanner, which can communicate with the specific control units in your vehicle.

Here's a general procedure for diagnosing the issue:

1. Access the OBD-II Port: Locate the OBD-II port, which is typically found under the dashboard, usually near the steering column.
2. Connect the Scanner: Plug your Mitsubishi All System Scanner into the OBD-II port.
3. Power On: Turn the vehicle's ignition to the 'ON' position (without starting the engine).
4. Activate Scanner: Turn on your scanner device.
5. Select Vehicle Details: From the scanner's menu, select 'Mitsubishi', then choose the correct model of your vehicle (e.g., Outlander, Lancer, Mirage, Eclipse Cross).
6. Navigate to Control Unit: Scroll through the scanner's options to 'Control Unit Select'.
7. Select ASC System: Choose the 'ASC System' module, as this is where FCM-related fault codes are often stored.
8. Read Fault Codes: Select the option to 'Read Fault Codes'.

The scanner will then display any diagnostic trouble codes (DTCs) stored in the ASC module, which have caused the FCM system to become disabled. These codes will provide crucial information about the nature of the malfunction, guiding you or your technician towards the correct repair. In some instances, the ASC system itself may require a software update, which typically needs to be performed by a Mitsubishi dealer due to specialised tools and software requirements.

Symptoms and Potential Causes Table

To further assist in understanding potential issues, here's a summary of common symptoms and their likely causes:

Frequently Asked Questions About FCM

What does "FCM temporarily not available" mean?

This message usually means the Forward Collision Mitigation system is temporarily unable to function. Common reasons include heavy rain, snow, or physical obstructions like mud or leaves blocking the radar and camera sensors at the front of your vehicle. Once conditions improve or obstructions are removed, the system should reactivate, possibly after a vehicle restart.

Can the FCM system prevent all accidents?

No, while highly effective, the FCM system cannot prevent all accidents. It is designed to help prevent or reduce the severity of frontal collisions by warning the driver and, if necessary, applying the brakes. Its effectiveness can be limited by factors such as vehicle speed, road conditions, and the nature of the obstruction. It is a mitigation system, not an absolute prevention system.

Why is my Mitsubishi's FCM system showing "SERVICE REQUIRED"?

A "SERVICE REQUIRED" message typically indicates a more persistent or significant issue than a temporary unavailability. This could be due to physical damage or misalignment of the radar assembly (perhaps from a previous minor bump), a software glitch, or an internal malfunction within the system's components or wiring. Professional diagnosis using a Mitsubishi-specific scanner is usually needed to pinpoint the exact cause.

How do I troubleshoot FCM issues myself?

For temporary issues like "FCM temporarily not available," you can check and clean the front radar and camera sensors for any visible obstructions (dirt, snow, leaves). If the message persists or you see "FCM SERVICE REQUIRED," it's advisable to use a Mitsubishi All System Scanner to read the fault codes from the ASC module. This will provide specific diagnostic trouble codes (DTCs) that indicate the problem. For complex issues or software updates, a dealership or qualified mechanic with specialised tools may be required.

Are there any known recalls for Mitsubishi FCM systems?

Yes, Mitsubishi Motors North America has issued recalls for certain models (e.g., 2018 Outlander PHEV, Outlander Sport, 2018-2019 Eclipse Cross, and 2017-2018 Outlander) equipped with FCM. These recalls were often related to incorrect software that could cause unintended braking. It's always a good idea to check with your Mitsubishi dealer or the official NHTSA website (for US vehicles) to see if your specific vehicle is affected by any open recalls, as addressing these can resolve system issues.

Conclusion

The Forward Collision Mitigation system is an invaluable safety feature, significantly enhancing the protection offered by modern Mitsubishi vehicles. While robust, understanding its operational nuances, recognising warning signs, and knowing how to respond to system messages are crucial for every driver. Whether it's a simple cleaning of sensors due to adverse weather or a more involved diagnostic scan to address a "SERVICE REQUIRED" message, prompt attention to FCM warnings ensures that this vital safety net remains fully functional. Always consult your vehicle's owner's manual or a certified Mitsubishi technician for detailed guidance and professional assistance to keep your FCM system in optimal condition, ensuring your peace of mind on every journey.

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