The Chevy Tahoe is a head-turning full-size SUV.
But like any other vehicle, it’s not uncommon for the alarm to go off at random.
If you’re Tahoe alarm keeps going off this article is here to help.
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Why Does My Chevrolet Tahoe Alarm Keep Going Off?
A Chevy Tahoe alarm can go off at random for the following reasons: faulty hood or door switches, a weak 12V battery, key fob issues, animals climbing on the vehicle, unlocking the car with the manual key, bugs triggering the internal motion sensors, aftermarket alarm issues, a faulty BCM or electrical interference.
1. Faulty Door Switch
The most common cause of a false alarm on a Chevy Tahoe is a faulty door switch.
The door switch is an electrical switch, located inside the latch. It monitors the state of the door, when the alarm is armed the door should be shut.
If the switch is dirty, faulty or broken it can trigger false alarms.
It’s a good idea to give all latches a good clean and spray some WD40. to see if that remedies the situation.
Here’s what one owner on tahoeyukonforum.com had to say:
“It’s very possible you may have a door switch that is just starting to go bad. A neighbor of mine had the exact same thing happen, but his was an earlier year. His would go off as soon as the temperature got around 30 degrees which was usually in the middle of the night. Yes, we were all happy once he figured it out.”
If you suspect you have a faulty switch, you can ask your dealer to run some scans on your vehicle to pinpoint the faulty switch.
2. Faulty Hood Switch
A faulty hood switch is another common cause of false alarms on the Tahoe. 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. 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.
Here’s what one owner on tahoeyukonforum.com had to say:
“I have read about this before on the 2015+ and in most instances it was blamed on low battery power, odd as it may seem your battery shouldn’t be going bad already, but just something to take into consideration for whatever it’s worth.”
4. Key Fob: Weak Battery or Faulty
A faulty key fob or a low key fob battery can cause problems with the alarm system.
For the sake of a few dollars, it might be worth buying new batteries for your key fobs. It’s best to buy a reputable brand of battery and ensure the battery is inserted correctly.
It’s a good idea to open the fob and give it a good clean as dirt and debris build-up can have a negative impact on the electronics.
You can do this with some rubbing alcohol and a cotton swab.
If you suspect your fob is broken you can also ask your local dealer to repair it, which should work out cheaper than buying a new one.
Avoid carrying big metal objects, electronics or a second coded key on the same keyring as your primary key fob as this can cause problems too.
5. Animals Climbing On The Vehicle
If your alarm has been set off in the middle of the night, it may have been by an animal climbing on the car.
Have a look for footprints on the hood and the roof.
Here’s what an owner on tahoeyukonforum.com suggested:
“No cat or raccoon footprints on the truck either? Could security lights on the house going on and off be setting it off?”
6. Faulty Locks
Another cause of false alarms is faulty locks on the liftgate glass.
Here’s what one owner on Reddit.com/r/ChevyTahoe had to say:
“Check the locks on the lift gate and back window to make sure they’re working properly. I had a problem with the lock on the lift gate glass (it wasn’t locking) and that was causing the alarm to go off because all of the locks on the vehicle weren’t locked.”
They went on to explain how they solved this:
“Removed the plastic cover from the interior back hatch and locked it manually.”
7. Unlocking The Door With The Manual Key And Not The Fob
On some Chevy Tahoe models, you will find that the alarm is triggered if you use the manual key to unlock the vehicle. This is because the vehicle should be unlocked with the fob.
Here is how one Tahoe owner on chevroletforum.com simply described it:
“Using the key to unlock the door will set off the alarm. Using the remote to unlock the door will not set off the alarm.”
8. Bugs Triggering Interior Motion Sensors
On some Tahoe models, the car has interior motion sensors. If there is a bug trapped inside of the car, then it can trigger the alarm.
If you have interior motion sensors and the alarm goes off unexpectedly, then this is a very likely cause.
Here’s what owners had to say on tahoeyukonforum.com:
“To update, I’ve been deactivating the interior motion sensors since and it hasn’t happened again. However, I didn’t do that tonight and so far nothing.”
“I had a bug flying around in mine one night, it drove me crazy.”
9. Aftermarket Alarms Issues
If your Tahoe has an aftermarket alarm installed, then its improper installation or faults with the alarm may be the root of the problem.
These alarm systems are often more complex than a basic factory-installed alarm but are often installed by people who aren’t competent.
If you have an aftermarket alarm that’s causing you problems it’s best to have it tested by an auto electrician or someone who specializes in aftermarket alarm systems.
It may also have overly sensitive sensors which can be triggered by loud noises, gusts of wind or even a cat climbing on top of it, in which case you’ll need to have the sensitivity adjusted.
10. Accidental Press Of The Panic Alarm
Some owners may have triggered the panic alarm by mistake by accidentally pressing the panic alarm button.
This can be easily done if you’re wearing tight pants, bending down to pick something up or have other items in your pocket with your key fob.
Here’s what the Tahoe owners manual says:
“Press and hold the panic button for more than three seconds to activate the panic alarm. The turn signal lamps flash and the horn sounds repeatedly for 30 seconds. The alarm turns off when the ignition is turned on or the panic button is pressed again. The ignition must be off for the panic alarm to work.”
11. Body Control Module Issues
A common cause of false alarms on the Tahoe, is body control module issues.
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
12. Electrical Interference
Electrical interference such as parking underneath overhead power lines or parking near a HAM radio can trigger the alarm on your Tahoe.
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 Chevrolet Dealership
If needed, take your Chevrolet 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 Chevrolet’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.
Pull the Horn Fuse
Is your horn the alarm on your security system?
If so, pull the horn fuse.
That should keep it from going off all hours of the day and night.
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.