I have a 2020 Ford F150 XLT pickup truck. Recently, the alarm started to get triggered randomly at night. At first, I thought someone was perhaps messing with my truck or attempting to open the doors, etc. But when the alarm got triggered multiple times the next night, I knew something else was the cause.
Common Causes & Fixes for Alarm on a Ford F150
The following are common causes for the alarm to be triggered. I’ll share what my culprit was after the list.
- Body Control Module (BCM) Software: For newer models like the 2021 F-150, false intrusion alarms can stem from software bugs that require a dealer update (such as Ford Service Special Message SSM 49601).
- Faulty Hood Latch Sensor: The truck thinks the hood is open even when it is closed. If locking the truck results in a double honk instead of a single beep, or a “hood ajar” warning appears, you likely need to replace the hood latch assembly.
- Dying 12V Battery: A weak or failing truck battery drops voltage and confuses the security system. Test the battery voltage (it should be around 12.6V off) or clean and tighten the terminals.
- Interior Motion / Intrusion Sensors: Bugs, flies, or windows left slightly open can trip the overhead motion sensors. You can change the setting in your gauge cluster menu from “All Sensors” to “Perimeter Sensing”.
- Key Fob Issues: A low battery in your transponder key or accidentally hitting the panic button in your pocket can set off the alarm.
In my case, the truck had its original AGM battery that was over 6 years old. I used a multi-meter to test the battery voltage level. It read 11.7 volts. That was definitely a problem. I replaced the battery and the random alarms stopped.
Why would the alarm get triggered in the middle of the night?
The night time temperatures at my house had recently dropped, and this made sense that the alarm was only triggering at night instead of the daytime, as car batteries tend to have a drop in voltage when the ambient temperature drops.
So if you experience random alarms on your Ford F150 at night, check your car battery!