The Accent is a popular subcompact car from Korean auto giant Hyundai.
As is the case with any vehicle, occasional false alarms or nuisance triggers of the alarm is possible.
If your Accent’s car alarm keeps going off, this article will help you identify potential causes.
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Why Does My Hyundai Accent Alarm Keep Going Off?
A Hyundai Accent alarm can be triggered by a weak 12V battery. Other than this, common causes include key fob issues, issues with the hood switch, faulty door switches, aftermarket alarms, wiring issues and electrical interference.
1. Drained 12V Battery
The most likely factor behind your car Accent’s car alarm system going off is a weak or failing 12V car battery.
When a car’s battery fails to maintain voltage levels above a specific level, unexpected alarm activations (as well as other electrical anomalies) are likely to follow.
Under normal usage, a 12V car battery should last roughly 3-5 years.
If you have had the battery for a long time then it might be time for a replacement.
Before buying a new battery try cleaning the battery terminals and make sure the connections are tight to see if this makes any difference.
If this hasn’t improved things, it’s a good idea to get the battery tested.
In the absence of a multimeter in your garage (we’ve included a battery testing guide at the end of this article), we suggest taking your car to the nearest AutoZone as most branches offer complete battery health checks, free of charge.
2. Key Fob Issues
A key fob that is dirty, faulty, or most commonly, has a low battery can lead to the Accent alarm going off at random.
We suggest cleaning the inside of the fob with some rubbing alcohol and a cotton swab and replacing the battery as a first course of action.
If you have a second key fob you can clean it and change the battery also.
Replacing the battery of a Hyundai key fob is relatively easy. It is getting into the key fob that is the challenge.
Follow the steps below to quickly replace your key fob battery:
- Determine the key fob type by referring to your owner’s manual or a quick Google search
- Most models use a CR2032 Coin Battery
- Prepare a prying tool (a small flat-head screwdriver or something similar)
- Locate the seam or groove of your key fob where the two halves of the casing meet.
- Once located, gently insert the prying tool and gradually apply pressure to separate the two halves of the key fob.
- Once open, locate the old battery, take it out, and firmly embed the new battery in the slot.
- Ensure the battery is the correct way up
3. Hood Switch Problems
One factor that goes under the radar when diagnosing random alarms is a faulty hood switch. This component has been known to fail on various Hyundai models including the Accent.
Also known as the hood latch sensor, this component is in charge of detecting the position or status of the vehicle’s hood (shut or open).
It is a simple mechanism – if the hood is “open” when the alarm is armed, then this will trigger the alarm.
However, if the hood switch is faulty it can send the incorrect signal to the car’s computer thus triggering the alarm.
Despite the relative simplicity of the hood switch, problems with it may arise due to dirt, grime, wear and tear and even manufacturing errors.
For the average car owner, checking the integrity of the hood switch is no easy feat.
This is why we recommend having your hood switch inspected by a technician at your local Hyundai service center (or even a reputable mechanic).
Based on information we obtained from Hyundai forums, some owners’ car alarm systems went off because of a faulty hood switch.
Check out what they had to say below:
“It’s more than likely the hood switch as it’s a common Hyundai problem and much easier to fix that than disabling the alarm.”
“The problem turned out to be the switch under the hood that was connected to the alarm.”
4. Faulty Door Switches
Faulty door switches are another likely culprit that can lead to random triggering of the alarm, especially since these switches are closely related to whether or not the Accent’s alarm should go off.
Much like a hood switch, an Accent’s door switches are in charge of detecting if a door or trunk is open.
If these sensors detect that a door or trunk is open once the alarm has been armed, then this will trigger the alarm.
If the switch is faulty then it can mistake a closed door for an open one, and vice versa.
Issues with the door latch can also cause alarm issues so its a good idea to give all the door latches a good clean.
Ensure they are free of grime and give them some WD40 which can be worked in by opening and closing the door.
5. Aftermarket Alarms
If your Accent has an aftermarket alarm fitted (one that did not come fitted as standard with the car) then this may have been incorrectly installed or it may be faulty.
It may also have additional sensors which might be damaged or overly sensitive.
Aftermarket alarm systems are often more sophisticated than a typical factory-installed car alarm but are often installed by people who aren’t mechanics.
If you have an aftermarket alarm that’s causing you problems it’s best to have it examined by your nearest Hyundai dealership or an auto electrician.
6. Accidental Press of the Panic Alarm
One simple and often overlooked reason for a false alarm on the Accent is accidentally pressing the panic alarm on the key fob.
This can be easily done when the fob is in your pocket, especially when wearing tight clothes or bending down to pick something up.
Here is what the Accent owner’s manual says:
“Press and hold the Panic button for more than one second. The horn sounds and hazard warning lights flash for about 30 seconds. To cancel the panic mode, press any button on the remote key.”
7. Damaged Wiring
Damaged electrical wiring can cause a wide variety of issues, especially with the alarm system.
Damaged, corroded or faulty wires aren’t easy to find and you’ll need to have an auto electrician carry out some fault finding on your car.
A common point of failure for electrical wiring is in and around the doors,.
If you’ve had some kind of water leak in your car then this issue is one to investigate.
8. Electrical Interference
Parking underneath or within close proximity of overhead power lines can cause false alarms from your Accent.
If you notice your alarm goes off, but only in certain locations, then it could be some kind of electrical interference from power lines or even a HAM radio.
This phenomenon is caused by electromagnetic radiation (EMR) which can interfere with the electronics on your alarm system.
If you suspect this is the cause, try parking somewhere else out of the way.
Check for Recalls or TSBs
By entering your car’s VIN number on Hyundai’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 Hyundai Dealership
If needed, take your Hyundai 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.
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.