Ford Truck Alarm Keeps Going Off (Solved)

So you’re peacefully sleeping at 2:30 a.m. and your Ford Truck alarm goes off in your garage or driveway. You frantically wake up looking for your keys to turn the alarm off to avoid complaints from the neighbor. But it’s already too late. The damage has been done.

So why does this keep happening? How can you fix it?

In this article we will discuss in detail some potential causes for this problem.

After reviewing forums and watching videos, there are three most likely causes to the alarm randomly going off in the F-150. These causes are that the interior alarm system is activating, there are faulty door ajar or hood latch sensors, or a known false activation of the Anti-Theft alarm system in the F-150.

ford truck alarm keeps going off featured image

What is the Anti-Theft Alarm System in the Ford F-150?

Built into the F-150 is a passive anti-theft system. This system is activated when the engine is off and the car is locked.

It is composed of :

  • interior sensors that detect movement inside the vehicle
  • inclination sensors that determine if the vehicle is being lifted
  • perimeter sensors that detect unauthorized vehicle entry

So the alarm that is sounding from a vehicle is any one of the triggers above.

It can be triggered by:

  • door, tailgate, or hood opening
  • power is activated with incorrect key
  • movement is detected inside the vehicle
  • movement detected that the truck is raised
  • the battery is disconnected
  • a trailer is disconnected

If you notice that your alarm goes off, you want to check these few things before investigating that there is a problem. Make sure there is no evidence of these triggers setting off the alarm.

Then the next thing you can do it buy and download a scanner tool and software to pull the alarm trigger history.

Using the OBDLink MX+ OBD2 Scanner, you can pull the alarm trigger history on your iPhone, Android, or Windows computer.

OBDLink MX+ OBD2 bluetooth scanner

OBDLink MX+ OBD2 Scanner

Amazon Affiliate Link

And if you want to connect to Windows with this software: https://forscan.org/

This resource will help you identify exactly what caused the alarm to sound. If you bring your car to dealer, they will likely perform this for you as well to help identify the cause.

After you have identified these aren’t the case, then you can look through the next possibilities.

Interior Alarm Sensing

In the Ford F-150 there is both an interior and exterior alarm system. The interior alarm system is located in the overhead box.

The interior system detects motion or interference inside the vehicle. This can be particularly problematic when you have a dog inside the car.

The system as well may have sensitive sensors for the interior causing minor disturbances to trigger the alarm.

How to fix Sensitive Interior Alarm Sensing?

If you are in need of a quick fix, this is a good first option.

This strategy involves deactivating the interior sensors so that only the exterior anti-theft sensors are active.

This can be done with the following steps:

  1. Navigate to the dashboard menu
  2. Scroll to “Settings”
  3. Scroll down to “Advanced Settings”
  4. Select “Vehicle”
  5. Select “Alarms”
  6. Select “Perimeter Sensing”

See the video below for a visual walkthrough of these steps on the dash.

Now you have set your F-150 to only detect exterior triggers to the alarm. This is the primary mode of alarm protection for break-ins to vehicles.

Another solution here is that you can just leave your car unlocked. The alarm that is going off is only activated when the car has been locked. Though this isn’t recommended, it is a potential solution, especially if your car is kept in a safe and secure location.

False Activation of Anti-Theft Software

There is a known issue, particularly in the 2021 Ford F-150 regarding a false activation of the anti-theft software. This issue is due to the Body Control Module (BCM) detecting vibrations that are non-threatening.

This could be the reason for your truck alarm going off randomly. This is a product wide issue that causes increased sensitivity in the sensors from the software to trigger the alarms to sound.

How to fix False Anti-Theft Software?

Unfortunately this solution involves brining your F-150 to the dealer. This issue is a known issue that was released by the National Highway Traffic Safety Administration announcing a Special Service Message claiming a possible issue in the software of the BCM.

This problem was fixed by many F-150 owners by updating the BCM. This can only be done by the dealer. So you may want to bring your vehicle for servicing, mentioning this SSM and determining if this is the cause.

See the SSM announcement from NHTSA here: https://static.nhtsa.gov/odi/tsbs/2021/MC-10188006-0001.pdf

Faulty Door/Hood/Tailgate Sensors

As mentioned earlier in this article, the alarm will sound when the door, hood or tailgate is opened when the car is locked.

This means the alarm may trigger if the sensor on these parts is faulty. It may sense any of these doors are open when in reality they aren’t.

You may first want to investigate these parts to identify whether there is actually a problem with the latch or the electronics.

The video below goes through full troubleshooting to identify the problem from either the latch or the wiring.

One of the long term issues of this problem is that it will cause the exterior lights to stay on even after locking the car which can eventually lead to the battery draining.

How to fix a faulty door, tailgate, hood latch?

If after all the steps are followed above and you have identified that one of the latches is faulty, you must replace it.

You can either bring it to a mechanic/dealer or perform the fix yourself. The next video here show you how to change the actual latch in the hood.

Though this next solution is a bit amateur, it still may possibly fix the problem, at least it did for this guy.

The solution here is just to shut the door harder. I guess this could potentially be a fix, but it’s not necessary a permanent solution.

Conclusion

If your Ford F150 alarm is randomly going off, you can bring it right to a dealership as they will be able to investigate the problem, but if you want to do it yourself these are the recommendations.

You will first need to determine why the alarm is prematurely going off with a scanner such as the one below.

OBDLink MX+ OBD2 bluetooth scanner

OBDLink MX+ OBD2 Scanner

Amazon Affiliate Link

Once you have the particular problem, you can either:

  1. Deactivate interior sensors
  2. Fix a broken latch
  3. update the BCM software

These fixes aren’t guaranteed to solve the problem, but they are the most likely causes and solutions.

You should always consult a professional before making any major changes to your vehicle.

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