The Subaru Crosstrek is an incredibly popular vehicle for adventurous people.
Even though it is renowned for its ruggedness, its alarm can be triggered at random and for unknown causes.
If your Crosstrek (also known as a XV in other countries) alarm keeps going off, this article is here to help…
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Why Does My Subaru Crosstrek Alarm Keep Going Off?
The Subaru Crosstrek alarm can be triggered by a dying or weak 12V battery, a faulty door lock mechanism, a malfunctioning keyless entry system, using the valet key, oversensitive alarm shock sensors, accidentally pressing the alarm button on the fob, key fob issues and hood latch issues.
1. Dying or Weak 12V Battery
A dying or weak 12V battery is the most common cause of Subaru Crosstrek false alarms. A 12V battery that is dying or has an insufficient voltage can trigger the alarm and cause several other problems for your Crosstrek.
The Subaru Crosstrek 12V battery usually lasts 3 – 5 years. It may require replacement if it is outside of this time period. Depending on when you purchased the vehicle or replaced the battery, it might be time for a new one.
Before buying a new 12V battery, inspecting the one under your Crosstrek’s hood first is worthwhile.
A loose or faulty connection can also cause the battery not to work correctly.
If you have a multimeter in your garage, check the condition of the battery yourself. If not, head to your nearest AutoZone – they offer free battery health checks.
You can also try disconnecting the battery, cleaning the battery’s terminals with a toothbrush dipped in baking soda and water mixture, and then reconnecting the battery.
When reconnecting the battery, ensure the connections are tight and free of any obstructions on the terminals.
Note: Make sure the engine is turned off before doing any work on the battery
2. Faulty Door Lock Mechanism
There are numerous reports from owners who have found that their Crosstrek alarm was triggered due to faulty door lock mechanisms.
One owner on SubaruXVForum.com shared their experience of random false alarms with their Subaru Crosstrek:
“Every time I opened the driver’s side door the alarm would go off. But the alarm didn’t go off when I opened the passenger door. In my case, the driver’s side door wasn’t actually locking (I could see from the passenger window that the red lock switch wasn’t moving when I pressed the lock button on the door handle or FOB). So I flicked the physical lock switch (not the electronic button) back and forth, and everything has been fine ever since.”
In that same thread, another owner chimed in with their solution to the problem:
“This also happened to me recently but it was the passenger door that wasn’t locking. I went through the same process and determined that the lock wasn’t actually engaging on the front passenger door. After manually locking/unlocking it a few times it seems to be fine.”
In both cases, the door lock gets stuck.
By locking and unlocking the doors and listening to the lock/unlock action of each door and tailgate, you will be able to identify which lock is stuck.
Simply working the stuck lock a few times by hand – and lubricating it with some WD40 – will remedy the problem a thing of the past.
3. Malfunctioning Keyless Entry System
No vehicle is free of gremlins – especially of the electrical kind. The Subaru Crosstrek is one of North America’s most reliable and dependable models, but even it has a few electric glitches.
One such glitch on the Subaru Crosstrek is with the keyless entry system.
An owner describes the problem in a SubaruXVForum.com thread:
“Not sure why this is happening, but my panic alarm goes off whenever I try to enter my car through keyless entry…. Only way to get the car to unlock without the alarm is to use the remote.”
Another owner posted their experience and the solution:
“Aaarrgh. I had this happen on my 2018. I’m sorry I don’t remember the precise steps I took but they were on the settings menu on the dash screen. I used “Reset to Factory Settings” on one of the menus. I feel bad I can’t offer more guidance but I was just blundering through trying things myself and I was surprised when the reset worked. It did completely solve the problem for me.”
There are many such reports of these glitches with the keyless entry system.
Resetting the keyless entry system back to factory settings may remove the glitch.
However, you will need to reprogram your individual preferences for the keyless entry functions, such as opening only the driver’s door or all doors, the use of the door’s touchpad, and more. This can be completed via the car’s dashboard menu.
4. Valet Key Randomly Triggers Alarm
Using the valet key – or setting their Crosstrek into valet mode – leads to many owners complaining about the alarm being triggered. This happens mostly to Crosstrek models equipped with keyless entry and push-button start systems.
One owner shared their experience on SubaruXVForum.com:
“Just realized my spare key is only a valet key. Tried it out and while it unlocks the drivers door it immediately sets off the alarm. Alarm stops when you start the car.”
Another owner who experienced the same situation posted in the thread of their solution:
“As far as I know, with models equipped with push to start, you press the lock or unlock button on the keyfob. If your keyfob is dead you put it up against the start/stop button and it will turn off the alarm. Models without push to start will probably be turned off when you put the key in to start it up as you said. It’s a shame the blank key doesn’t have a chip built-in like Honda or VW vehicles do.”
5. Oversensitive Alarm Shock Sensor
The Subaru Crosstrek alarm can be triggered randomly by oversensitive alarm shock sensors.
These Subaru models are equipped with a fantastic alarm system although they can be quite sensitive. As many owners have discovered, the alarm systems can be triggered by knocks, bumps, planes flying overhead and wind.
On some models however, the Crosstrek’s sensitivity setting that can be adjusted.
In many instances, the default setting of the Crosstrek’s alarm system is set to its maximum. This can be adjusted by a dealership or workshop upon request.
An owner posted the following query on the ClubCrosstrek.com forum regarding this problem:
“I own a 2015 xv limited. The alarm fires with any sound or breeze. Do anyone help me find the knob or method to lower the sensitivity. Looking under the steering wheel reveal multiple boxes with cables, none of them I could find a knob on.”
Another owner shared the solution:
“You need to have access to special Subaru Monitor software which connects to the ODB2 port. I figured it was cheaper to just visit the dealer to get it enabled and adjusted.”
6. Accidental Press of The Alarm Button On The Fob
A common reason why a Subaru Crosstrek alarm goes off at random is due to owners accidentally pressing the alarm button on their key fob.
The alarm button can be easily pressed in owners pockets when sitting down or when bending down.
7. Hood Latch Sensor Issues
The hood latch sensor is designed to trigger an alarm if someone tries to force open the hood – if it is broken or dirty it can cause the alarm to go off.
Dirty / Rusted Hood Switch
Due to the location of the hood switch, its not uncommon for it to get very dirty – this alone is enough to trigger the alarm at random. Corrosion and rusting of the hood switch is also very common, which can also trigger the alarm.
Its a good idea to give the hood latch a thorough clean to remove any gunk buildup.
It’s also a good idea to spray a little WD40 too lubrication.
Faulty Hood Switch
It’s not uncommon for the hood switch to get damaged or fail completely.
If the switch that monitors whether the hood is open or shut isn’t working then this can trigger the alarm.
Replacing the hood switch is a fairly cheap and easy process, however if you are not mechanically inclined, have your local dealer replace it for you.
Here’s one owners advice from the Crosstrek subreddit, after one owner explained that the wind popped the hood and set off the alarm:
“The hood pop triggering the alarm makes sense (i.e. it functions normally). I would guess that the latch wasn’t closed all the way last time and the wind just picked it up a bit. You have to hold the hood about 2 feet from being closed and drop / slam it to close it; if you just press it down gently it won’t latch.
If all of that is old news to you, then it’s gotta be a faulty latch. Properly functioning hood latches basically don’t let go; hoods rarely fly open in car crashes anymore for instance.”
8. Faulty Key Fob
A key fob that is dirty, damaged, faulty, or needs a replacement battery can trigger your Crosstrek’s alarm to go off at random.
Open your key fob (as if to replace the battery) and clean any dirt, grime, and grit that may have entered the device.
Clean the battery contacts carefully with some rubbing alcohol and a soft cloth.
If you have given the key a good clean and the alarm is still triggered, you should change its battery.
Key fob batteries are cheap to buy, but its best to get a good quality one.
Once you’ve replaced the battery, try to lock and unlock your car using the key fob. If the alarm still goes off, you may need to contact your dealer or an auto-electrician.
Disconnect the Battery
Sometimes mysterious alarm problems can disappear with a simple reboot, there are no guarantees here but it’s worth a try.
Disconnect the battery for 20 seconds and this resets many of the electronics in the vehicle.
Pull the Horn Fuse
On some Subaru Crosstrek models by pulling the horn fuse you disable the alarm temporarily until you find a solution.
Check For Warning Messages
When the alarm occurs can you see any lights or warning messages on the instrument panel?
This can give a clue as to what’s causing the alarm e.g. ‘Hood Ajar’.
Take it to a Subaru Dealership
If needed, take your Subaru to the dealership.
Tell them you are NOT paying for a check on what the problem might be.
Ask them if they will check it for free.
Most dealerships and other places do quick/initial diagnosis for no money as they plan to make money for the repair of your vehicle.
If you’re Chevrolet is still under warranty then they should fix and resolve the issue for free.
Check for Recalls or TSBs:
By entering your car’s VIN number on Subaru’s recall page or the NTHSA’s Safety Issues & Recalls page you can determine whether or not there is a TSB or recall for your vehicle and if there is you’ll want to get it addressed.
A recall is issued by a vehicle manufacturer for issues that are safety-related, while a TSB covers components that may be malfunctioning but don’t compromise the safety of the vehicle.
Test the 12V Battery
How to Test the Battery
- Before testing, remove the surface charge from the battery, this allows for an accurate reading.
- Simply turn on the headlights for 2 minutes then turn off.
- Set the multimeter dial to the ’20 Volts’ setting.
- Make sure the car is turned OFF
The multimeter will have a red probe and a black probe:
- The red probe is for making contact with the positive terminal
- The black probe is for making contact with the negative terminal.
Measure across the battery terminals.
- The meter should display a reading, if the battery is fully charged the voltage should be between 12.2 and 12.6 volts.
- Anything under 12V and the battery should be charged or replaced.