How to reset a factory car alarm

How to reset a factory car alarm
How to reset a factory car alarm

Although car alarms are very useful, most of the time they annoy users more than they help them. These devices turn on unpredictably, refuse to turn off and frighten the whole neighborhood. Because of the importance of your car's safety, you can learn a few methods to troubleshoot your vehicle's alarm. So, with a few simple methods, you can be sure your car is safe and running smoothly.


Part 1 of 3: reset a factory car alarm

Reset a Factory Car Alarm Step 1

Step 1. Open the car manually

If the remote control alarm does not work, use the key directly. Most of the time, opening the door will stop the alarm. If the driver's door does not open, try opening the passenger side door.

Reset a Factory Car Alarm Step 2

Step 2. Start your vehicle

Place the key in the ignition and turn on the car. If that does not deactivate the alarm, try turning the dashboard lights on and off several times without warming up the engine.

Reset a Factory Car Alarm Step 3

Step 3. Make use of common tips

Factory car alarms have simple reset protocols that will allow you to turn off the alarm. Most of the tips are based on using the key in the door. Just insert it, as many factory car alarms have a sensor on the door, which can be a quick fix.

  • Place the key in the driver's door and turn it twice to the right, then twice to the left. Then put it in the ignition and start the vehicle.
  • Turn the key until it is in the open position and hold it there for 2 seconds before opening the door.
Reset a Factory Car Alarm Step 4

Step 4. Disconnect the battery

If the alarm still sounds after the first solution, you should have the siren silenced as soon as possible. Car alarms work through the electronic component of the vehicle and, if you disconnect the battery, the siren will be deactivated and the alarm will reset. Open the hood, locate the battery slot, and using a wrench, remove the negative terminal. Then reconnect it after a minute.

You have the option of unplugging the set of cables which is connected to the car horn or siren, if it is easily accessible. If the horn or siren is unplugged, it will no longer make a sound

Reset a Factory Car Alarm Step 5

Step 5. Reset the alarm

Locate it and the transmission system. Find their exact location in the vehicle's owner's manual. Press the reset button or turn it off and on.

Reset a Factory Car Alarm Step 6

Step 6. Remove the fuse from the alarm

This should deactivate the alarm and disable it until the fuse is replaced. You will find this in the fuse box. Take it out and put it in a plastic bag. You can store it in the glove box to keep it safe.

  • If you cannot quickly find the alarm fuse, remove it to see if the alarm will stop. This will not damage the car, but be sure to replace the fuses, but first check that they are not the alarm ones.
  • Some car alarms, when tampered with, prevent the vehicle from turning on (anti-theft function). If you remove the fuses and the car will not start, you will need to go to a mechanic or dealer.
Replace Car Keys Step 9

Step 7. Press the panic button

You can also press the ones on the key control to stop the alarm. Since this button can trigger it, it can also turn it off. Pressing the trunk release or unlock button may silence the alarm because it disables the car's security system.

Reset a Factory Car Alarm Step 7

Step 8. See a mechanic if the problem persists

If none of these methods of resetting the alarm work, try talking to a mechanic or dealer. If the doctor can identify the problem over the phone, it can easily be fixed. However, he may need to come in person to make a diagnosis.

Part 2 of 3: Turn off the car alarm

Reset a Factory Car Alarm Step 8

Step 1. Talk to a dealer or mechanic

Disabling a car alarm can be a temporary solution before calling a professional. Remember, however, that car alarms are designed to prevent theft and when tampered with, some systems prevent the vehicle from starting, as a safety measure.

Reset a Factory Car Alarm Step 9

Step 2. Understand the basic concepts of an alarm system

Alarm systems have a few components.

  • The control box: in general, this part is considered a brain, because it functions as the control center of the system.
  • The alarm transmitter: it comes in two forms, either a remote control or a key.
  • Sensors: alarms vary and can be complex with various sensors, namely those for windows, doors or pressure.
  • Siren: Alarms need some type of warning signal. Some systems have their own siren system, while others are connected to the car stereo.
  • Cables: the wires connect the siren to the control box, and the latter to the fuses as well as to the sensors.
Reset a Factory Car Alarm Step 10

Step 3. Disconnect the battery

Open the hood and locate the battery. Use a socket wrench to unscrew the negative (-) battery terminal and remove it. This is a security measure. Operating a vehicle's electronic system can be dangerous.

Reset a Factory Car Alarm Step 11

Step 4. Find the alarm system

If you have a factory alarm in your car, consult the owner's manual as a guide. The alarm system is almost always under the hood, near the wheel. If you installed an alarm in the car after purchasing it, you will find it anywhere, but most companies install it under the wheel.

Reset a Factory Car Alarm Step 12

Step 5. Disconnect the cables

Some alarm control blocks have labels for each wire. To deactivate and silence the alarm, you can remove the cables connected to the control unit and the wires connected to the siren.

  • Pull the siren cable to remove it. This will turn off the alarm and may be a temporary solution before you seek professional help.
  • Take out the control box. If you remove the brain, the car won't have an alarm. However, depending on how the alarm is installed, it may also prevent the car from starting.
Reset a Factory Car Alarm Step 13

Step 6. Reconnect the battery and test the car

After disconnecting a cable, reconnect the battery to make sure the alarm is no longer sounding. Start your car and warm the engine up a bit to make sure it is still running.

Part 3 of 3: Solve alarm problems

Reset a Factory Car Alarm Step 14

Step 1. Repair an alarm that starts to sound when you turn on the car

You may need a new battery. Disable the alarm by removing its fuse, then take your car to the garage. Mechanics can examine the battery and, from there, see if the problem is with the alarm system.

Reset a Factory Car Alarm Step 15

Step 2. Identify an alarm that never works

Lock the car electronically using its control (if you have one). Manually press the door lock if the control fails to close the door or if you do not have this feature. Use your remote control key or press the lock button on the driver's side door. If that doesn't work:

  • disconnect the negative terminal of the battery;
  • turn the key to the on position;
  • replace the negative battery terminal again;
  • turn the key to the off position;
  • turn on the car.
Reset a Factory Car Alarm Step 16

Step 3. Repair the alarm if it sounds randomly

If your alarm sensors are improperly calibrated, you should adjust them so that they stop causing problems whenever a dog approaches the car. To do this, see the Alarm system section in the vehicle manual. Most cars can be calibrated to be less sensitive without taking them to a garage. There are two types of alarm sensor controls.

  • Dual inline box switches: This is a group of toggle switches that control the amount of electricity flowing through the sensors. Disabling a few will make your alarm system less sensitive. These are integrated into the main control box of the alarm system.
  • A rheostat: Use a small screwdriver to loosen the bolt that adjusts the resistance on the sensor, making it more or less sensitive. These sensors are installed outdoors.
Reset a Factory Car Alarm Step 17

Step 4. Check if the alarm is the reason the vehicle does not start

When a car does not start, many people perform several checks to identify the problem. If after all the checks you can't find a solution, consider reviewing the car alarm. Some are connected to the contact as a security measure against theft. Try turning off or resetting the alarm, then try starting your car again.


  • Just disconnect your alarm or battery as a last resort. Your alarm should work when you need it.
  • When handling the electronic system of any car, the battery should be disconnected for safety.

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