The Chevy Avalanche is a full size pickup truck that was produced from 2002 to 2012.
Like any vehicle, it can develop issues with the alarm system.
If your Avalanche’s alarm keeps going off, this article is here to help...
Table of Contents
Why Does My Chevrolet Avalanche Alarm Keep Going Off?
A Chevrolet Avalanche alarm is usually triggered by a faulty door switch or hood switch. Other common causes include battery problems, key fob issues, and a damaged fuse box.
1. Faulty Door Switches
Faulty door switches are another common cause of random alarms on the Avalanche, these switches monitor the open/closed status of the door – if damaged, faulty or dirty they can send false readings thereby triggering the alarm.
Door switches are a common point of failure as they are subject to wear and tear due to the doors being continually opened/closed/slammed etc.
The door latches and door switches can get dirty too which can cause issues, so the first thing you should do is give all door latches a good clean and spray some WD-40 on the latch and work it in to see if that helps.
Also check the wiring leading from the body into the door for any signs of damage, it should be in a flexible hose on the hinge side of the door.
One Avalanche owner was given this advice on Reddit.com/r/CarTalk:
“You have a broken wire or wires, making a dead short in the door boot connecter, look at the rubber boot that goes between the door and the A pillar ( side of your dash ) by the door hinges.”
If you suspect the alarm issues are linked to the door switch, ask your dealer to run a diagnostic test to try and pinpoint the fault.
2. Faulty Hood Switch
A faulty hood switch is a common cause of unwanted alarms for Chevrolet vehicles (Avalanche included).
The switch is typically embedded in the hood latch.
The small electronic device is designed to detect whether the hood is open or shut and is an important part of the car’s alarm system – if it is broken, loose or dirty it can send false readings to the car’s computer thus triggering the alarm.
- Pop the hood and locate the hood switch.
- Check for any obvious damage, rust or loose connections.
- Give the hood switch a clean too (use contact cleaner), as dirt and grime can cause issues.
- You can test the switch with a continuity tester.
If you are well-versed mechanically, you can buy a new hood switch online and replace it yourself. Otherwise, we’d advise visiting your local mechanic.
3. Loose or Bad 12V Battery Connections
Loose or bad 12V battery connections can cause a number of problems, including triggering the alarm of your Avalanche.
A bad connection can be caused by dirt or gunk buildup.
The terminals may have come loose from driving and vibrations etc.
Make sure the engine is off before doing any work on the battery.
- Inspect the battery and look for any signs of damage, dirt build-up, rust, or corrosion.
- Disconnect the battery and loosen the nuts on the clamps using a wrench.
- Remove the negative clamp, marked with a – symbol first.
- Clean the terminals with a toothbrush dipped in a mix of baking soda and water, rinse with distilled water and dry with a cloth.
- Reconnect the battery, ensuring tight connections.
4. Drained 12V Battery
A faulty or weakened car battery causes a variety of problems, including accidentally triggering the Avalanche alarm.
The best thing to do is take your Avalanche for a battery health check, these are usually quite inexpensive or sometimes free such as at AutoZone.
Or you can test it yourself with a multimeter (see the guide at the end of this article).
A healthy 12V battery should be about 12.6 to 12.8 volts while a weakened battery reads below 12 volts.
5. Faulty Key Fob
Another reported cause of nuisance alarms on the Avalanche is a faulty key fob.
If you have 2 remotes, try taking the battery out of one and using the other for a while.
If the alarm problems persist, and you have tried cleaning the inside of the fob(s) and changing the battery, the best thing to do is speak with your dealer.
You may need a new key fob or need your existing fob re-programmed.
6. Key Fob Running on Low Battery
A common cause of mysterious alarms on the Avalanche is a low key fob battery. Similarly, if the fob is dirty or dusty this can also cause alarm issues.
Give the inside of your fob a clean and replace the battery to eliminate this possible cause. It’s worth spending a bit extra for a good brand of battery.
- To open your key fob, stick your prying tool into the slit or gap between the two halves of the outer casing and gently apply upward pressure to pop open the device.
- Remove the battery.
- Give the key fob a good clean to remove any dirt or fluff – a cotton swab and some rubbing alcohol should do the trick.
- Check for damage, rust or loose connection (you may need a new key fob depending on what you find).
- Be sure to insert the new battery facing the right way up.
- Assemble the outer casing of your key fob by clamping them back together.
7. Incorrectly Installed Aftermarket Alarm
An incorrectly installed or faulty aftermarket alarm system is a common cause of nuisance alarms.
Aftermarket alarms are typically far more complex than any factory-installed equipment which makes them more prone to issues.
They may also have been installed by incompetent individuals.
If you are experiencing issues with an aftermarket alarm, the best thing to do is speak with a reputable auto electrician.
8. Damaged Alarm System or Faulty BCM
In some cases, the computer of your stock alarm may be faulty.
This can be quite technical to diagnose and fix.
We suggest booking an appointment with a trusted mechanic or your dealer for a more comprehensive assessment.
“Most likely the alarm brain is fried. You should be able to look into the fuse box and pull an alarm fuse, or a horn fuse, both should keep it quiet until you can get it checked out.” – ChevyAvalancheFanClub.com
Similarly, a faulty body control module can cause a wide range of issues including nuisance alarms.
- The BCM is in charge of electrical communication from different electronic systems.
- This includes the car alarm system, lock-unlock functions, climate control etc.
9. Damaged Circuits Inside The Fuse Box
Corroded and damaged circuits inside the fuse box have been a reported cause of nuisance alarms on the Avalanche.
Locate the fuse box, open it, and visually inspect for any obvious signs of damage or corrosion.
If the circuits inside are compromised then the fuse box will need to be replaced.
“Everything pointed to the fuse box. I believe I bought mine on Amazon for around 200. There are several circuit boards in the fuse block that get corroded. Very simple swap out – pull the 2 handles up, unhook 2 red wires and pull it out and swap the new one in.” – ChevyAvalancheFanClub.com
Related: 13 Best & Worst Chevrolet Avalanche Years (Facts & Stats)
10. Rust and Corrosion on Door and Hood Latches
Rust and corrosion can damage the latches and switches, which may trick the sensors into detecting that a door is open.
Inspect the vehicle’s doors for any sign of rust or corrosion.
You may need to replace one or more of the latches but first try giving them a good clean and applying some lubrication such as WD-40.
11. Damaged Wiring
Damaged electrical wiring can cause a wide range of problems, it can often be tricky to pinpoint too and you may need to have an auto electrician run some diagnostic tests.
Due to the soy-based material used for certain cables and wiring, rodents may have nibbled their way through some of the cables.
An auto electrician will be able to run some diagnostic tests and visually inspect the wiring harness.
12. 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.
States such as Illinois, Indiana, Iowa, Texas, Wisconsin, and Carolina have large wild raccoon populations.
Have a look for footprints on the hood and the roof.
If you have a CCTV system, examine the footage. These animals usually appear during the night.
13. Not Closing Doors, Hood, or Trunk Properly
Something as simple as not properly closing the doors, hood, or trunk will inevitably trigger the alarm.
Make sure to check if you have closed every point of entry of your vehicle to avoid accidentally tripping your Avalanche’s alarm.
Alternative Suggestions
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.
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 your unit is still under warranty then they should fix and resolve the issue for free.
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.
Sources
https://www.chevrolet.com/support/vehicle/manuals-guides
https://www.chevrolet.com/ownercenter/recalls
