Mitsubishi FCM Service Required: Causes and Fixes

Mitsubishi Forward Collision Mitigation (FCM) system is a safety system that ensures it helps stop an event of a collision or reduce the effect of a collision on the car and occupants. 

The FCM system uses many components, especially the radar sensor that helps sense the object’s distance at the vehicle’s form. 

When the components of the FCM get affected, so does the system. The FCM system does not function or malfunction, and the driver might not be aware of it. 

Once it senses that the FCM is not working right due to a failed part, the ECM will alert the driver through a warning message: the FCM service is required. Once the driver has been warned, the system might stop working until the issue is fixed.  

What is FCM Service Required?

When the FCM service required message comes, it means that there is something wrong with the Forward Collision Mitigation (FCM) System. It is usually caused by faulty rada or sensors. 

What is the FCM system? The FCM is a driver assistance system that helps monitor the distance between your vehicle and the one in front. Any sudden change in the distance between your car and the one in front that could lead to a collision will activate the system’s safety function. 

The FCM can activate the brakes automatically to help avoid a collision or reduce the damages that could occur if a collision should happen. 

In addition, the FCM system uses specific sensors that could be found built into the windscreen. The sensor helps monitor traffic and pedestrian at the front of the vehicle. 

A signal is sent to the system once the sensors or radar senses a potential collision. In response, an audio and visual warning will alert the driver. After the warning, moderate braking will be applied to encourage the driver to slow down. 

If the driver ignores all the warnings the system gives, the system activates emergency braking. It should prevent the collision or reduce the effect of the collision.

The FCM uses radar sensors that calculate speed and distance to help prevent the vehicle from collisions. When the sensor radar is damaged or obstructed for a particular period, the warning message FCM service required will come. 

Also, other faults that could affect the system’s performance, like electrical issues and system problems, could trigger the warning message. 

Causes of FCM Service Required

Due to the various components that work together to ensure that the FCM system works, there is more than one cause of FCM service required warning message. 

The most common cause of the warning message is a faulty radar sensor or electrical issues. 

Below are some of the causes of the FCM service required.

1. Radar interference 

Anything that stops the radar from sensing whatever is in the front of the vehicle will cause the warning message FCM service required to come up. 

The weather condition usually causes radar interference. It usually performs poorly during extreme snow. Snow could often cover the radar for a long time, not allowing it to send accurate data to the system. 

Also, during extreme rain, the radar will not get precise reading readings to the system, which can hinder it from working. 

In bad weather conditions, you can do nothing to stop the warning message from coming up. The system will work perfectly when the weather is okay, and the warning message will disappear. 

2. Damaged radar 

Once the radar or its wires are damaged, the FCM system will not function because it cannot keep track of vehicles and pedestrians in front of the car.

Sometimes the issue with the radar could be dirt and needs to be cleaned. In other cases, it could be a more severe issue that may need replacing the radar sensor.  

3. Software issue

The FCM may sometimes malfunction due to software issues, so you may need to reprogramme. In this case, you will need professional help. 

Simple malfunctions might not be serious, and you may need to reset the system. Resetting the system is easy; we will look into it later in this article. 

4. Battery issue

The battery is responsible for powering the FCM system because it is an electronic component. Current flows from the battery to the system, communicate with the sensors, and carries out essential actions.  

The vehicle may start once the battery is weak or failing, but electrical components like the FCM system will not function properly due to a lack of electricity. Issues like this will trigger the FCM service required, alongside other warning messages and lights.  

5. Wiring issue 

The wiring connection is responsible for delivering electric current to the FCM system. It also carries signals from the sensors to the system. 

When the system’s wire harness is damaged in any way, electric current will slow down or not flow to the system. It will cause the system to stop working or malfunction. 

Also, the sensor’s wire will hinder the sensor from functioning and transmitting signals to the FCM system.

How to Fix an FCM Service Required?

When fixing an FCM service-required warning message, you first need to determine what the cause could be. You can do this through proper diagnosis using a scan tool or physical inspection. 

The easiest way to diagnose a problem like this is by using a scan tool. All you need to do is connect the scan tool to your vehicle, test the sensor radar, and run a scan for related error codes. 

Below is how to fix an FCM service-required warning message. 

1. Fix the radar sensor

Two significant issues could affect the sensor, such as a wiring problem or a damaged sensor. First, you need to ensure the issue is coming from the sensor. 

Use a scan tool to test the sensor; most scan tools will give an available or unavailable response. If, after the test, the result of trying any of the sensor radars is unavailable, then you need to check and fix the sensor. 

Locate the sensor using the owner’s manual and examine the wires first. Check for broken or exposed wires, disconnection, and corrosion. If any is found, then have the wire changed. 

Next, check the sensor for damages; if there are no apparent damages, it could be that the sensor is dirty; have it cleaned. If the sensor is damaged, replace it with a new one. It should be the same type as the damaged sensor. 

2. Software issue 

The best way to fix a software issue is by resetting the system. There are numerous ways to do so; however, the most trusted is by using a scan tool. All you need to do is clear all the error codes on the vehicle’s ECU using the scan tool. 

Furthermore, you can try disconnecting your vehicle’s battery if you do not have a scan tool. Disconnect for about 15 to 30 minutes. It will give it time for the systems to drain out of the all-electric current. The system memory will automatically wipe when this is done. 

3. Fix the battery issue 

First, you need to have the battery tested using a multimeter. Below is how you can test a car battery using a multimeter. 

  • Turn off your vehicle and all electrical components like lights and radio. 
  • If the multimeter is not set, set it to DC voltage.
  • Place the black probe on the negative terminal and the red probe on the positive terminal.
  • The battery must be charged if the reading is below 12.4 volts. 
  • If the multimeter reading is 9.5 or below, the battery is bad and should be replaced. 
  • Fix wiring issues 

Use the vehicle manual to trace the wire related to the FCM system. Once you can get to the wire, inspect it for corrosion, disconnection, or exposed wire. If you find any, then the wire should be replaced immediately. 

Final Thoughts 

It is possible not to have significant symptoms when you have a failing FCM system. However, your vehicle will stop sending collision messages, and the warning light will come. Due to the less significant symptoms, people are less motivated to repair the system. 

It is essential to take the FCM service required seriously, especially if you drive in a place with heavy traffic. It could be life safer for you and prevent you from future collisions.

  • Edmond Davis

    I'm Edmond Davis, an automotive expert with years of experience in vehicle repair, performance, and safety. I graduated from the University of Michigan with a degree in Automotive Engineering and have worked with major companies like Ford, GM, and Chrysler. I'm a trusted source of information for anyone looking to learn more about cars or improve their driving experience.

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