There’s nothing anxiety inducing than hearing your Honda Civic’s alarm going off in the middle of the night randomly. Not only are you annoying the neighbors, but there’s still that nagging doubt your car is getting stolen for real… although it probably isn’t.
Just how do you stop a Honda Civic alarm that keeps going off, whether while driving, after a battery charge, when it rains, or just at random? Here’s all you need to know.
Why does my Honda Civic alarm keep going off? Your Honda Civic alarm keeps going off at random and won’t stop for a range of possibilities including corroded terminals, faulty sensor, low battery level, wiring issue, key fob battery issue, unevenly closed doors, all of which and more are explained below.
That’s my brief synopsis. If you want to get to the bottom of your Honda Civic alarm going off randomly, here’s all the possible reasons and what you need to do.
Honda Civic alarm keeps going off
Before I get into the reasons, another way which the alarm can get set off is the occasional “user error”. By that I mean, sitting on the key fob… just saying!
1. Key fob battery issue
Your key fob could be the culprit as it contains a small radio transmitter that “talks” to the receiver in your Civic to help you unlock doors and use the keyless ignition button.
However, if can also result in your Civic alarm going off at random when you least expect it.
This either happens when there’s a fault with the key fob, or the battery needs replacing. I’ve previously written about how to enter your Civic when the key fob battery is dead – it shows how to replace the battery.
2. Faulty sensors in the door lock
Sensors anywhere in your Civic could also be the reason for the alarm issue. For example, if the door sensors get damp due to a window seal leak or are harmed as a result a collision into the car’s door, it can start tripping the alarm.
3. Problematic ECU / control module
Modern Honda Civics come with an ECU (Electronic Control Unit) that help maintain and monitor engine performance. It’s an on-board computer that monitors all the sensors I previously mentioned, as well as fuel economy and other optimisation factors.
This is great but can come with a cost.
If the ECU develops a problem, it might send the wrong signal to the wrong place, and before you know it, your Honda Civic’s alarm keeps going off when you don’t want it to… possibly at night, when driving, or after a battery change.
Of all the problems listed this is the one thing you will find it hard to fix yourself. Your ECU will need repairing and possibly reprogramming.
4. Low car battery or corroded battery terminals
If you heard your Honda Civic alarm, randomly go off then suddenly it stops then it could be where the car battery is low, possibly even further drained by the alarm sound.
The alarm tends to go off as soon as you put the key inside the ignition. One thing some people say works is to rev the engine for a while to put more power into the dying battery.
It might also be where you have a loose connection from the car battery where the battery terminals have started to rust and corrode.
5. Poor installation of your alarm system
Honda Civic owners will often want to install a more advanced alarm as it’s the most stolen car in the United States. However, during the installation of aftermarket alarm systems, it might not be fitted correctly.
This will often lead to your Honda Civic alarm going off in the rain or at night if too sensitive or wired incorrectly… speaking of which…
6. Wiring fault / disconnected circuitry
Faulty wiring can set an alarm off randomly. If it’s a wiring issue it will often be accompanied by the Civic beeping at random, and headlights also flashing at the same time.
7. Poor hood latch connection
If your hood isn’t closing properly or the small sensor in it has faulted, it could trigger the alarm. Newer Civics have a sensor in the hood designed to tell you if it’s open or closed.
Check if the dash warning light goes on when the hood latch is open.
Handy Hint: Here’s how you can open the hood of your Civic from the outside.
8. Highly sensitive shock sensors /software issue
Sometimes one of the sensor’s sensitivity is set too high meaning a minor detection can cause it to go off. Try reading the manual to check yourself how to decrease the sensitivity and reconfigure it as you please.
How to fix these problems
- For key fob issue try to change the battery. Also check whether the buttons are working properly or not. Clean the fob.
- For bonnet latch check if the plug is still attached to the switch, use a manual or seek guidance from someone about the plugs switch and join the two.
- For other sensors, you could take your car to the nearest Honda service station, and they will run some tests on their computer to check if all sensors are working, as they should. They will tell you if the component must be replaced or it may be repaired easily.
- Low car batteries simply solved by keep the car running for some time or try charging it through another source.
- Poor installation and wiring fault both can be checked through some software at servicer station either the required functions are working properly, or it is giving false signals to the ECU.
- Software in the fob and a car’s ECU can be updated or reinstalled as you need.
Honda Civic alarm keeps going off after battery charge
If you have just charged your Civic’s alarm and the battery goes off, it might indicate that the battery has not been charged enough.
Alternatively you might have knocked or disconnected another sensor whilst charging the battery.
Honda Civic alarm going off while driving
If your alarm is going off while driving, it’s likely due to an ECU connection or wiring issue. If you can try to isolate what it is you are doing when the alarm goes off. For example, does it happen when you push a button or indicate?
Honda Civic alarm going off in rain
Rain and wind will often set off a Honda Civic alarm seemingly at random. It will often be due to the vibration of the rain hitting the car that can set off interior motion detectors Your alarm sensors are too sensitive so could be dialled down by the dealer.
One more serious issue could be water getting into the trunk and soaking sensors of the ECU components.
A friend of mine also suggested this for the Honda Civic alarm keeping going off in rain:
“It’s the sound of the rain hitting the door where there is a sensor fitted. The dealer fits some insulation between the door and the sensor.”
Honda Civic alarm goes off when opening the door
If the alarm keeps going off when you open the door, take a look at the interior door panel. You’ll find a switch attached to the back of the key lock cylinder or somewhere near.
Don’t forget to check the jamb wiring harness below the door for any damaged or broken wires, also use a voltmeter to check if power or ground gets to the opposite side of the switch when the key is used to lock and unlock the door.
In this case, I would replace the switch. I don’t believe there is a passenger side keyhole, but if the car has one, try unlocking it from there and see if you still experience the problem.
How to reprogram the ECU in my car?
Repeat the following steps to reprogram alarm software in your car… this is more something I recommend you get a dealer to do, so here are just simple instructions I picked up online.
- Get specific ECU-TEC instruction with related car model.
- Connect your car’s interface with OBD-2 cable and start the engine.
- Use Pro-ECU software tool to detect your car model etc.
- Chose the desired program for your engine.
- Select that ROM file and modify it as you want.
- Put specific name on it to identify it for future use.
- Run diagnostics (make sure any electronic device such as mobile phones are away from the system)
- Do the on-screen instructions and start the ignition.
Did your Honda Civic wake you up at 5 in the morning for no reason? Or does it starts beeping in the middle of the night with a high risk of disturbing not only your family but your neighborhood too?
It’s tough, but hopefully you can now diagnose what the issue is with my guide.