ACC FCW Limited Functionality: 3 Tips To Fix The Warning

Like many other automakers, Jeep has recently equipped its vehicles with ACC/FCW systems. Despite how great and helpful this technology is, there are times when you may need to fix it for various reasons. In that case, you will get an “ACC FCW Limited Functionality” message on your display.

To fix the “ACC/FCW Limited Functionality” issue, reset the ACC/FCW system. Then, clean the windshield, front camera, and ACC/FCW sensors. You also need to maintain proper alignment and verify the connections. Calibrating the camera also helps in this situation.

ACC FCW Limited Functionality
ACC FCW Limited Functionality Jeep Warning

This article will examine these typical problems and how to fix them if your ACC/FCW system isn’t working correctly. For more details, read the article all the way through.

What Are ACC and Fcw?

Adaptive cruise control (ACC) and forward collision warning (FCW), two driver assistance features, are combined in ACC/FCW. The purpose of each feature is to keep drivers safe while driving. Both features, which frequently come with the standard Advanced Driver Assistance Systems (ADAS) package, are available on Jeep vehicles.

Adaptive Cruise Control (ACC)

To keep a safe distance from the vehicle in front of it, the Adaptive Cruise Control (ACC) system automatically modifies the vehicle’s speed. Additionally, it makes it possible for drivers to keep their desired speed while on freeways or other open roads without frequently accelerating and decelerating.

The acceleration or deceleration of the car is automatically adjusted as a result of ACC, which employs sensors to detect the speed and distance of other vehicles. 

Forward Collision Warning (FCW)

The purpose of Forward Collision Warning (FCW) is to aid drivers in avoiding collisions or minimizing their effects. It keeps an eye on the car in front of it and warns if a collision is about to happen.

FCW systems also support automatic emergency braking (AEB) by providing the information required to start braking. 

By sending you an alert, FCW gives you extra time to react before a collision or lessens the impact’s severity by starting emergency braking. As a result, it can be used to reduce or prevent injury in the event of an accident. Any malfunction in this FCW system will result in an “ACC FCW Limited Functionality” warning.

What Causes the “ACC Fcw Limited Functionality” Warning?

It’s not always a sign of a problem in your car when you see “ACC/FCW limited functionality” on your screen. A false message display could be the result of an electrical issue.  

If an electrical problem is not to blame, your screen’s limited or non-functional ACC/FCW functionality can be attributed to the following factors. 

Blocked Sensor Due to Heavy Rain, Snow, or Dirt

In extremely severe weather, such as heavy rain, snow, fog, or freezing temperatures, ACC/FCW systems may not function. 

This is because the weather may temporarily blind the sensors that detect other vehicles, rendering them incapable of doing so. 

The sensors may also be dirty when it occurs. The sensor’s radius can be blocked by debris and dust. As a result, an “ACC FCW Limited Functionality” warning will appear. 

Misaligned Camera Behind the Mirror on the Windshield

The misaligned camera behind the windshield mirror is a significant factor in why the message appears on your screen. This frequently occurs when you replace your windshield.

The Wiring System in the Lower Grill Is Faulty

If the sensor’s wiring in the lower grill area is damaged, you’ll see the “ACC FCW Limited Functionality” warning message. The possibility of a wire short circuit exists. Damaged sensors may also trigger alerts to be sent to you.   

Incorrect Camera Settings

A damaged camera or sensor sometimes prevents ACC/FCW systems from functioning correctly. The message “ACC/FCW Limited Functionality Front Camera Service Required” will appear on your screen.

In this situation, you must resolve the camera-related issues. These fixes can be very expensive. Some owners claim that the cost to fix their ACC/FCW system was at least $1,800!

Inadequate Lighting

The amount of light on the road has an impact on ACC/FCW systems as well. In low light, it’s possible that the sensors won’t be able to detect other vehicles. When driving at night, ensure you have enough visibility by using your headlights and other lights.

Driving Through Areas With Lots of Reflective Surfaces

The performance of ACC/FCW systems can also be affected by driving through areas with many reflective surfaces, such as tunnels or highly reflective asphalt. This is because the reflection may temporarily blind the sensors, preventing them from performing as intended.

Damaged Sensors/Cameras After Collision

The sensors and cameras may be impaired or damaged if the vehicle has experienced a collision. This frequently occurs, especially in front-end collisions, which may impact how well the ACC/FCW system works.

If so, you must take your car to a mechanic so they can examine and fix the damage.

Faulty Battery

ACC/FCW limited functionality can also result from a bad car battery. Ensure that your Jeep’s battery is in proper working condition

Consider checking the battery’s health. If the battery is faulty or weak, replacing it with a new and functional one can potentially resolve the problem.

Software Bug

Finally, ACC/FCW systems may stop working due to a software bug or a bad update. If so, you should bring the vehicle to a dealership for maintenance and software upgrades. 

How Do You Fix the “ACC FCW Limited Functionality” Issue?

Apply the following fixes to resolve the ACC/FCW limited functionality.

1. Reset the ACC/FCW System

If the message appears due to an electrical issue, you must first reset the ACC or FCW system.

You should do this by carrying out the following actions:

  1. First, take the vehicle’s battery out. The negative terminal should be removed first, followed by the positive terminal.
  2. Wait for 15 – 20 minutes. The vehicle’s power will eventually run out.
  3. After that, reconnect the battery by adequately adjusting the terminals.
  4. When you check the dashboard, the message should be gone.

But if it’s not an electrical issue, you should keep reading. 

2. Clean the Front Windshield, Sensors, and Camera

Dirty sensors or a dirty windshield are the most frequent causes of ACC FCW limited functionality.

So, if you reset the car and the message persists, you must look for snow or dirt on the ACC or FCW sensors. If they’re dirty, you should clean them right away.

An FCW or ACC sensor can be cleaned with windshield washer fluid or wet glass wipes. Make sure the sensor, camera, and windshield surfaces are all clean. You don’t need to remove the sensors, windshield, or front camera for cleaning.  

Clean Radar Sensor in Front of Vehicle Jeep Grand Cherokee Warning
FCW OFF: Clean Radar Sensor in Front of Vehicle

Best Way to Clean ACC/FCW Cameras and Sensors

A soft, lint-free cloth works best. To remove any filth or debris, use a moderate cleaning solution such as diluted vinegar or rubbing alcohol.

To remove any obstinate particles, use a soft brush or pressurized air. Avoid corrosive or abrasive substances, which could harm the camera and sensor housing. When cleaning your cameras and sensors, always follow the manufacturer’s instructions.

3. Calibrate the Front Camera Settings

If the windshield, sensors, and camera are all clean, you should carefully examine the front camera. When the front camera has to be serviced, the car occasionally displays ACC/FCW limited functionality.

If you see this message, you must calibrate the front camera. But, if the camera isn’t calibrating, you should check for a faulty electrical connection.

Adjust the wire to the proper location before attempting to calibrate it again. If it doesn’t function, inspect the dashboard, which typically leads to the front fascia being replaced.

How Serious Is the “ACC FCW Limited Functionality” Issue?

The situation should worry drivers who depend on this feature for safety. Unwanted accidents are more likely because of ACC/FCW limited functionality. If there’s any obstruction on the road, the driver can’t be warned by the ACC or FCW.

These two technologies use sensors to scan the road and alert the driver. But the technology might stop working because of some restrictions

The warning about ACC/FCW limited functionality won’t stop you from driving. However, you must know that active braking won’t be completely available in this situation.

Guidelines to Avoid the “ACC FCW Limited Functionality” Warning

You can take numerous steps to avoid seeing the “ACC FCW Limited Functionality” warning. First and foremost, keep your cameras and sensors clean and clear of dirt, dust, and debris. This ensures that the sensors can detect other cars accurately.

Be sure to also pay attention to the weather and avoid situations while driving where your ACC/FCW system might encounter issues. Always use your headlights and other lights appropriately when it’s dark or foggy. 

Frequently Asked Questions (FAQs):

Q1. Where Are the ACC FCW Sensors and Radar Located?

Jeep houses the Adaptive Cruise Control (ACC) and Forward Collision Warning (FCW) sensors and radar within and around the front grille assembly.

Specifically, the sensors are positioned on the passenger side and on the driver’s side of the front facia. 

The radar is usually in the middle of the front grille or under the grille on the fascia.

Q2. How Much Does the “ACC FCW Limited Functionality” Repair Cost?

The cost of fixing an “ACC FCW Limited Functionality” issue may vary based on the specific problem. Generally, you can be looking at spending anywhere from $100 to $1,000 for the repair.

If your sensors or radar are dirty, you don’t need to pay anything to clean them.

If your windshield is dirty or damaged, it can block the camera, hindering its performance. Cleaning or replacing the windshield may cost you around $100 to $300.

When the radar or sensor itself is faulty, a replacement is necessary. This is a pricier fix, usually ranging between $500 and $1,000.

If there’s trouble with the wiring connecting the radar or sensor to the ACC/FCW system, repairs are needed. Fortunately, this is a more budget-friendly fix, around $100 to $300.

Q3. How Do You Fix the ACC/FCW Unavailable Service Required Warning?

If you’re dealing with the “ACC/FCW Unavailable, Service Required” warning, start by checking and cleaning the front sensor, especially if you’ve been driving in dirty or challenging road conditions. 

In adverse weather, like heavy snowfall, wait for conditions to improve or clear any accumulated snow on the sensor. 

If the sensor is damaged, a careful inspection is necessary, and you may attempt to reset it before considering a replacement. 

Ensure proper brightness levels for the sensor, avoiding overly bright areas.

Verify that your Jeep’s grille is compatible and not blocking the sensors. Address issues like loose connections, electrical problems, or misalignment of the front radar or sensor.

Diagnose and fix problems related to the car’s computer, connectors, or battery. Always consider checking the windshield and sensors for proper installation and cleanliness.

Q4. How Do You Fix the ACC/FW Unavailable Wipe Front Radar Sensor Warning?

If you’re facing the “ACC/FCW Unavailable Wipe Front Radar Sensor” warning on your Jeep, ensure the front radar and sensors are clean and free from dirt, debris, or obstructions. 

Wipe the sensor gently with a clean cloth. Check for proper sensor alignment, and if it’s misaligned, consider having it realigned at a licensed dealer. 

Verify that the bumper bracket is not bent, affecting the sensor’s alignment. Additionally, ensure the windshield in front of the camera is clean, without snow, ice, or other impediments. 

Q5. How Do You Fix the ACC & FCW Cannot Operate Radar Obstructed Warning?

If you’re dealing with the “ACC & FCW Cannot Operate Radar Obstructed” warning on your Jeep, check the radar area for any obstructions such as dirt, mud, or debris. 

Gently clean the radar with a soft cloth to ensure it’s free from hindrances. Verify that the bumper bracket is not bent, as a misalignment can trigger the warning.

Diagnose the problem, make necessary adjustments, or replace the radar if required. 

Q6. Can You Depend on the ACC FCW Systems in Practical Situations?

While Adaptive Cruise Control (ACC) and Forward Collision Warning (FCW) systems are designed to enhance safety on the road, their reliability in real-world scenarios is not infallible. 

These systems serve as supplementary safety features. Do not consider them a substitute for attentive driving. 

Factors such as adverse weather conditions, sensor obstructions, and system malfunctions can impact their performance. 

You must remain vigilant, exercise caution, and take control of the vehicle when necessary. 

Q7. Can the ACC FCW Systems Be Manually Turned Off?

Yes, in most vehicles, including Jeeps, you can manually deactivate the Adaptive Cruise Control (ACC) and Forward Collision Warning (FCW) systems through the vehicle’s settings or dashboard controls. 

For specific instructions tailored to your Jeep model, refer to your Jeep’s manual.

Read More: Stop/Start Unavailable Service Stop/Start System: 5 Tips to Fix the Error 

Final Words

Modern vehicles increasingly feature ACC/FCW systems, but they should always be used with other safety systems to be the most effective. They work well to lessen the impact and help prevent accidents.

However, several factors can sometimes cause them to malfunction. Knowing the most frequent reasons for the limited or non-functionality of ACC/FCW systems can help you troubleshoot problems and get back on the road more quickly, preventing this from happening.

I hope now you better understand the ACC/FCW Limited Functionality warning. Try the above-mentioned troubleshooting techniques until the message is completely gone. But if it doesn’t fix the car, you should let the experts look at it. To avoid accidents, always drive safely and obey traffic laws.

Sharing is caring!


  1. Question about the FCW as my jeep doesnt seem to give any warnings it is brand new 2023 Grand cherokee. are there any issues with FCW warnings.. it is all on and no error coming on the screen..just not sure why it doesnt give warnings even though the car in front of me was very close.

    1. If you aren’t seeing FCW warning, then it’s a difficult problem. Try resetting the FCW system. If that doesn’t work then you should visit your dealership. But it’ll be difficult to convince them of the problem unless it is clear for all to see.

  2. I have a 2016 Grand Cherokee SRT. I’ve been getting this warning, along with flickering dash and dome/vanity mirror lights, radio going on/off (I can hear the speakers connecting/disconnecting) and sometimes when I try closing my driver’s side window, it’ll go up halfway then lower. I’ve had my battery replaced (twice – dealership said the first replacement failed load test), alternator and most recently PCM to no avail. I’m scheduled to take it back in 2 weeks but I’m afraid if they cannot replicate it happening, I’ll be sent home again. I’ve been dealing with this for over a year. No issues starting, runs fine with the exception of the constant pinging from the warning, and I’ve yet to figure out what’s causing it.

    1. You have so many problems. Troubleshooting them is going to be tough. My first guess was the battery. But you have already replaced it. So, I guess you can start with the basics. Plug in a good OBDll scanner and carry it with you while you drive. When you face those issues, check to see if the scanner picks up any error codes. That may lead you to any problems that you can get fixed.

Leave a Reply

Your email address will not be published. Required fields are marked *