If the alarm key fob does not work


The overwhelming majority of modern cars are equipped not only with a central lock, but also with a standard alarm. There is a wide variety of models of these security systems. But the main problem they all have is the same - they do not want to respond to commands from the control panel. And this always happens at the wrong moment.

How to prevent the problem? Or if it does, how can you quickly fix it?

Failure reasons and problem solution

If the alarm key fob does not work

The first thing a person does when something does not work in his hands is to solve the problem by shaking and hitting. Surprisingly, sometimes it helps. However, in the case of expensive signaling, it is better not to use this method at all.

First, you need to figure out why the machine does not respond to pressing a button on the remote control. Here are the main reasons:

  • village battery;
  • radio interference;
  • wear of the security system;
  • the car battery has run down;
  • failure of electronics.

Most of the listed faults can be eliminated by yourself. Here's what a motorist can do to make the alarm continue to perform its function.

Dead batteries in the keychain

If the alarm key fob does not work

This is the most common problem with mobile remote control electronic devices. The easiest way to identify the problem is to use the additional remote control of the machine. They often come with a control unit. If the spare key has opened the car, then it's time to change the battery in the main key fob.

Usually, when a battery loses its capacity, it affects the range of the keychain. Therefore, if the car reacts to the signal each time at a shorter distance, then you need to look for a suitable battery. And you can't buy them in every store.

The vehicle is in a radio interference zone

If the alarm key fob does not work

If the alarm system suddenly stopped working after the car was parked near a secure facility, then the cause of the malfunction is radio interference. This problem can also be observed in large car parks in large cities.

If the driver cannot arm the car, you should find another parking spot. Some anti-theft systems are equipped with automatic activation. In this case, to turn off the signaling, you need to bring the key fob as close as possible to the antenna module.

Alarm system wear

Long-term operation of any device inevitably leads to its breakdown. In the case of car security, the signal quality of the key fob gradually decreases. Sometimes the problem may be with the antenna.

The quality of the transmitted signal can also be affected by incorrect installation of the transmitter module. It must be installed at a minimum distance of 5 centimeters from the metal parts of the machine. There is a little trick on how to increase the range of the key fob.

Life hack. How to increase the range of a keychain.

The car battery is empty

If the alarm key fob does not work

When the car is on the alarm for a long time, its battery is insignificantly discharged. In the case of a weak battery, this may be the reason why the car does not respond to the alarm key fob.

To open a "asleep" car, just use the key for the door. If the problem occurs in winter, then you need to diagnose the battery. The density of the electrolyte may already be low. In this case, it will be necessary to periodically recharge the battery.

Electronics failure

If the alarm key fob does not work

Old auto-wiring is another reason for signaling problems. Because of this, they can appear frequently and unexpectedly. It is impossible to say for sure in which node contact will be lost. To do this, you will need to test all wires. Without the right skill, this problem cannot be solved. Therefore, it is better to take the car to an electrician.

If the alarm behaves strangely (it reboots for no reason, performs commands incorrectly), then this is a symptom of a malfunction in the control unit. In this case, you also need to show the car to a specialist. You may need to reflash your device.

Alarm goes off by itself

Sometimes the anti-theft system "lives its own life." She either disarms the car, or vice versa - without a command from the key. In this case, you need to pay attention to three factors.

Contact failure

If the alarm key fob does not work

Oxidation of contacts is a common cause of inadequate signaling. Most often this problem appears in the key fob battery compartment. The malfunction can be solved by simply cleaning the contacts with Natfil, or by treating them with alcohol.

Otherwise, the car itself may send incorrect data to the control panel. Loss of signal on a rusty door or bonnet contact is recognized by the anti-theft system as an attempt to break into the car. If the key fob displays the arming zone, the problem is easier to fix. Otherwise, you will have to check all the connections in the anti-theft wiring.

The problem with door mechanisms

If the alarm key fob does not work

Another problem can arise in winter. The control panel shows that the central locking is open, but in fact it is not. Do not think that this is an alarm malfunction. The first thing to check is whether the door mechanisms are rusted or not.

It would also not hurt to test whether the central locking itself is working. If it does not make any sounds when the opening button is pressed, then it is worth checking the fuses or wires.

Incorrect sensor operation

If the alarm key fob does not work

In modern cars, anti-theft systems are connected to car sensors. The more complex this circuit is, the higher the likelihood of failure. The reason is either the contact has oxidized, or the sensor is out of order.

In any case, the machine control will show an error. Do not rush to change the sensor right away. Try cleaning the wire connection first.


As you can see, in most cases, the signaling malfunction can be eliminated yourself. The main thing is to figure out why the problem arose. The anti-theft system protects the vehicle from burglars. Therefore, alarms cannot be ignored. And if the car is parked in a dangerous area, you can use additional measures to protect it.



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1 comment

  1. Somehow I was in this situation. Barely twisted 🙂 There was interference from the transformer.

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