The Tiguan is one of VW’s best-selling models.
However, some owners have reported that the alarm goes off at random.
If your VW Tiguan alarm keeps going off, this article is here to help.
Table of Contents
Why Does My Hyundai Elantra Alarm Keep Going Off?
The main causes of random alarms on a VW Tiguan include triggering of the internal sensors, a faulty hood switch, faulty door switches, a weak 12V battery, key fob issues, a faulty body control module and electrical interference.
1. Accidental Triggering of Interior Motion Sensors
The VW Tiguan has internal motion sensors that detect movement inside the vehicle. When the car is locked and the alarm is armed these internal sensors can trigger the alarm by bugs that are trapped in the car, dogs left in the vehicle or even by the wind if the window has been left open.
The most common cause is bugs trapped in the vehicle, so if you’re alarm keeps going off its a good idea to have a good look inside the car to try and find the culprit.
If you are experiencing lots of random alarms on your Tiguan, you can also try disabling the interior sensors for a few days or a week. If the alarm stops going off you know that the issue is somehow related to the interior sensors – perhaps a faulty sensor or a bug is trapped inside.
Here’s what one owner had to say:
“There are swarms of ladybirds around at the moment and obviously some of them have got inside the car and are triggering the alarm.”
How To Disable The Alarm (Interior Alarm Sensors)
If you need to leave dogs in the car, have your Tiguan towed, or even put your Tiguan on a ferry – than it is possible to disable the alarms interior sensors.
Button On Door Pillar (B Pillar)
On Older models of the VW Tiguan (around 2018 and before) there is a button on the driver’s side door pillar – almost directly opposite to 1/2 way up the driver’s seat upright.
By pressing this button you can disable the interior alarm.
Remote: Click Lock Twice
You can also disable the interior sensors on some Tiguan models by using the remote key fob by clicking lock twice within quick succession.
Note: The double press also disables the deadlock, which the button on the B pillar doesn’t do.
On newer models, the interior sensors can be disabled via the infotainment / main touchscreen menu.
Simply follow these menu options:
- -> Settings menu
- -> Opening & Closing
- -> Central Locking
- -> Interior Monitoring
This doesn’t disable the alarm, just the interior monitoring function, and next time you lock the car it is reactivated automatically.
2. Faulty Hood Switch
A very common cause of the alarm being triggered on the Tiguan is a faulty hood switch. The hood switch is designed to detect a forced entry of the hood, if the switch is damaged, broken or dirty it can trigger false alarms.
You may even notice a warning message on the dashboard such as “hood ajar”.
The first thing to do is pop the hood, locate the hood switch and make sure it is free of dirt and grime.
If the switch is clean and you suspect it is faulty, you can buy a replacement online and fit a new one yourself if you are mechanically inclined.
Otherwise, the best option is to visit your dealer and have them fit a replacement.
3. Faulty Door Switch
Similar to the hood switch, a door switch monitors the doors and detects a forced entry. If the switch is faulty, broken or dirty it can trigger false alarms by sending incorrect signals.
The door switch monitors the state of the door, for example – when the car alarm is armed the doors are supposed to be closed.
If the alarm is armed, and the door switch is broken, it will trigger the alarm as the Tiguan thinks the door is being opened or is open when it shouldn’t be.
If you suspect you have a faulty door switch, contact your local dealer and they can perform some diagnostic tests to see if you do in fact have a faulty switch.
4. Weak 12V Battery
A weak 12V battery that has insufficient voltage can cause a wide range of problems, including triggering the alarm.
Most 12V car batteries last about 3-4 years so it might be time for a replacement, it’s worth cleaning the terminals first though and making sure the connections are tight and free from dirt and debris.
Tip: Clean the terminals using a toothbrush dipped in baking soda and water mixture
If you have a multimeter you can test the battery yourself – we’ve included a simple guide at the bottom of the article.
If not, you can visit your local mechanic, dealership or Auto Zone and ask them to do a battery healthy check for you.
5. Key Fob Issues: Low Battery, Dirty or Faulty Fob
A common cause of the VW Tiguan alarm going off at random is due to various key fob issues, most commonly a weak battery.
Clean The Key Fob
To start out, give the inside of the fob a good clean to see if this fixes this issue first.
Key fobs can collect a lot of dirt and gunk inside which can cause issues with the electrical contacts.
Simply get a cotton swab and some rubbing alcohol and remove any buildup.
Change the Fob Battery
If the battery on your fob is low or hasn’t been inserted correctly, this can trigger the alarm. To rule out this possibility you can change the key fob battery.
Batteries can be picked up for a few dollars. It’s also a good idea to get a reputable brand of battery and make sure the battery is inserted the correct way up.
If you have two key fobs, you should change both batteries or alternatively leave one fob with the battery removed to narrow down which fob might be causing the issue.
Faulty Key Fob
A faulty key fob can cause a wide range of issues, including triggering the alarm.
If you suspect your fob is broken you can ask your dealer to repair it, alternatively, you can buy a new one although it will need to be programmed.
6. Faulty Body Control Module
Your VW Tiguan alarm may be going off at random due to a faulty body control module.
The body control module or ‘body computer’ is the electronic control unit responsible for monitoring and controlling various systems associated with the vehicle’s body such as the alarm, immobilizers, power windows etc.
The body control module can develop corrosion on the pins or connections can become loose.
Other common symptoms of a bad BCM include:
- Repeated battery drain
- Starting problems
- Erratic electrical functions e.g. horn, wipers, lights, lights on the dash
- Security and alarm system problems
On tiguanforums.co.uk here is what one owner had to say:
“My dealer was great and traced the problem to a faulty control box. The system records every time the alarm goes off and what triggered it. They were able to tell that it was a fault as there was no trigger. Definitely one for the dealer to diagnose.”
7. Electrical Interference
Electrical interference such as parking underneath overhead power lines or parking near a HAM radio can trigger the alarm on your Tiguan.
This phenomenon is caused by electromagnetic radiation (EMR) which can wreak havoc on the car’s electronics.
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.
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 VW Dealership
If needed, take your Tiguan 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 your Tiguan 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 VW’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.
How to 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.