The modern car key has reached a new level in terms of ease of use and security. It allows only a certain person to gain access to the car and start the engine.
There are also simplified versions of these devices. But regardless of this, most car keys are necessarily equipped with batteries.
And these batteries tend to run out. Their charge drops below the minimum level, and the key stops functioning. To fix this, you need to replace the battery correctly and in a timely manner.
Special button
Each control panel has a special “Valet” button. Almost every car alarm manufacturer adds this button to the remote control just for emergency situations. If the purchase of a car took place in the showroom, then the manager had to show where this key was located.
In cases where the car was purchased on the secondary market, you should find out the answer to this question from the previous owner of the car.
What affects the service life
The service life of alarm batteries does not depend on the type of anti-theft system and its power. This parameter is affected only by the frequency of use of the remote control.
The service life of an alarm battery depends not only on its manufacturer, but also on other factors:
- Operating conditions. Power supplies are usually resistant to temperature changes and severe frost. But to increase service life, it is recommended to use batteries in moderate climatic conditions.
- Intensity of use. If a remote control with a display is used for the initial alarm setup, the battery will drain faster.
- Application of additional options for anti-theft systems. If a consumer uses multiple alarm functions, the battery will drain faster.
Modern security systems offer users the ability to control not only anti-theft options, but also other processes in the car. In practice, in alarm key fobs that use the autostart function, the power source discharges faster.
How to understand that the immobilizer is not working?
The main signs that the immobilizer does not recognize the key:
- the car indicator with a key or lock lights up or blinks on the dashboard;
- the on-board computer gives errors like “immobilizer, key, secret, etc.;
- When you turn on the ignition, you can’t hear the buzzing of the fuel pump;
- the starter does not work;
- The starter works, but the mixture does not ignite.
The reasons why the immobilizer does not see the key are divided into two categories:
- hardware - failure of the key chip or the unit itself, broken wiring, dead battery;
- software - the firmware has crashed, the key has become untied from the unit, an immobilizer glitch.
If there are no direct indications of a failure of the anti-theft lock, an independent check of the immobilizer should be carried out after eliminating other possible causes of problems. It is necessary to make sure that the fuel pump, starter relay, lock contact group and battery are in good condition.
Restoring an old battery
Sometimes some are faced with a situation where the battery is obviously dead, and it is not possible to purchase a new one right away. The only way out is to try to “resurrect” the battery, which has obviously become obsolete and is located in the key fob.
First you need to remove it from there and then begin to act.
- The simplest way to “cheer up” the battery for a while is heating. But the main thing here is not to overdo it - extreme temperatures threaten an explosion.
- In some cases, the “old-fashioned” method also helps - you need to knock on the battery, intensifying the chemical reactions occurring inside.
- You can try to recharge the battery from other power sources - you will need a couple of wires and at least minimal skills. We should not forget: during such blasphemous manipulations the battery will heat up.
But these actions are only suitable in a situation like “alone in the taiga, a hundred kilometers from the nearest store.” Ideally, every motorist needs to have a spare battery with him - you never know.
The service life of batteries, even when not in use, is limited, and therefore it is periodically necessary to examine the “reserve” to see if the date of possible use has expired.
Having studied all of the above, it becomes clear: there is nothing complicated in replacing the battery of a car key, which is so scary for many - the main thing is to understand the scheme for disassembling the case and remember that the time of action is limited.
Types of keys used
If you have problems with the ignition, first you should make sure that the key works and the batteries are not dead.
Although it is logical to start by determining whether there is at least any battery in your ignition key. You can understand this by what key is used for your car. There are several varieties:
- Standard or classic. There is no chip or microchip here. To the question of whether such an ignition key has at least one battery, you can confidently answer no. In fact, these are ordinary metal blanks with a certain cutting.
- Service with a rotating mechanism. More advanced option. There is a transponder chip here. At the same time, the functionality is limited only to manual opening of car locks. Not designed for remote work. Usually there is no battery.
- With radio-electronic transmitter and rotary mechanism. The key body contains a transponder and a microcircuit. They allow you to control the locks remotely. The battery is present.
- With release mechanism. It may be without a battery or with it.
- Smart key. Relevant for cars where there is no standard ignition switch, but a Start-Stop button is used. A battery is required.
Also, keys can be divided into main and spare. The second is usually a copy of the first or a slightly simplified version of it.
Which battery to buy
The golden rule for a motorist is not to buy a cheap “pill” for the key. This will cause the replacement to be made much more often, and problems may even arise in the system.
It is better to choose a battery similar to the one that was already installed in the key or opt for a well-known high-quality analogue.
In most cases, the car key is equipped with one of seven types of batteries. Some models have batteries that are recharged automatically - when the key is in the lock and the car is moving. But more often the battery is still a classic three-volt “pill”.
You can find out which one:
- After studying the operating instructions;
- By asking a question to an official dealer;
- Looking at thematic forums;
- Having disassembled the key body.
Video
The “Best China” channel presented a brief overview of CR2025 batteries purchased in China.
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Dead immobilizer battery
Today I would like to consider a situation when the battery in the immobilizer of the standard key suddenly runs out, and you need to drive.
Now you will say that this practically cannot happen. Indeed, most modern cars notify their owners about the low battery level by displaying this information on the display. It would seem, what’s going to happen here? That’s what I thought, until one of the weekends I spent relaxing with my family in nature. We went for a walk in a Honda N-WGN . It was frosty outside, the car key was in my jacket pocket all this time. When it was time to leave, the car refused to start. I was unpleasantly surprised by this surprise.
Standard remotes
In addition to the special “Valet” button, older cars have a basic key to open the doors. A dead battery on the remote control will in no way affect the engine ignition. If the battery on the remote control is dead or the buttons on the remote control do not respond to commands, use the key.
If the driver has not used a standard lock for a long time, you need to be careful and initially clean the lock from dirt and dust, and then open the door with the ignition key. The battery in the presence of a standard key does not have a colossal effect on the engine and the locking center.
Frequently asked questions when the immobilizer does not work
In conclusion, we offer answers to the most common questions that arise if the immobilizer does not allow you to start, does not see the key, sees it only once, or all the keys with the chip are lost/broken.
Can the immobilizer work if the key battery is low?
Passive tags do not require power. Therefore, even if the battery responsible for the alarm and central locking is dead, the immobilizer will be able to recognize the chip and unlock the engine start.
Do I need to use an alarm if I have an immobilizer?
Immo is not a full-fledged replacement for an alarm system, since it only complicates the thief’s task and does not prevent his access to the interior. The immobilizer does not allow it to start, but does not notify the owner in any way about a break-in attempt. Therefore, it is better to use both protective systems.
How to bypass the immobilizer when installing an alarm system?
There are two ways to bypass the immobilizer when installing an alarm system with an autostart system. The first is to use a crawler containing a spare key or chip. The second is the use of an emulator crawler connected to the immobilizer unit via the CAN bus.
Why does the immobilizer not see the key if there is an alarm system with auto start?
There are two options: the first - the crawler cannot scan the key normally (the chip has moved, the antenna has moved out, etc.), the second - the unit sees two keys at the same time: in the crawler and in the lock.
From time to time the car does not recognize the immobilizer key, what should I do?
If the immobilizer error occurs irregularly, you need to check the electrical circuits, contacts of the ECU and immobilizer unit, and the inductive coil transmitting signals to the chip.
Is it possible to link a new immobilizer to the ECU?
Sometimes the only way to start a car if the immobilizer is broken is to register a new unit in the ECU. This operation is feasible, as is binding a new controller to an old immobilizer unit, but the details of the procedure differ for different brands.
Why does the immobilizer work after disconnecting and connecting the battery terminal?
If the immobilizer light comes on and the car does not want to start without removing the terminal from the battery, you need to check the battery charge level. If it is normal, you should look for problems in the wiring. To prevent the keys from being disconnected and the immobilizer being blocked, do not disconnect the battery when the ignition is on!
How to unlock the immobilizer if there is no key and password?
In the absence of a linked key and password, unlocking is only possible with the replacement of the immobilizer and flashing the ECU with binding of a new immo block.
Is it possible to disable the immobilizer permanently?
There are three ways to remove the immobilizer lock permanently: - use jumpers in the immo block connector (old cars with simple protection); — connect an emulator to the connector of the security unit, which will tell the ECU that the key is inserted and you can start (for some modern cars); — edit the firmware or install modified software with the immobilizer functions disabled (VAZ and some other cars). The difficulty of disabling the immobilizer depends on the age and class of the car. This is easier to do on older and budget models than on new and premium ones. If none of the methods described above helped, you should contact a specialist. Auto electricians at dealership service stations, specializing in specific brands of cars, will be able to restore the functionality of the standard immobilizer. Chip tuning specialists will help you remove the blockage forever.
We act quickly
Many car enthusiasts are inclined to simply go to a workshop and replace the battery there, but you can complete this simple task yourself. True, you will have to act like a sapper - that is, carefully and quickly, and therefore it is better to read the instructions in advance, having built a procedure in your head.
If the chip key does not have power, the code in the anti-theft device begins to gradually erase - that is, the immobilizer will not be able to do so for more than five minutes without a battery, otherwise the key will have to be synchronized with the central locking control key fob.
What happens to the key if its battery runs out?
If your vehicle has an easy access system and a built-in automatic engine start system with a key, then this product provides electronic signals to the vehicle's built-in security system. It is through this interaction that the car recognizes its “ignition key fob” and fulfills the requirements of the driver, who presses the appropriate buttons.
The main conditions for the normal operation of this system include:
- serviceability of the key and car security system;
- visual access of the key fob to the car during activation of the door opening or engine ignition;
- presence of charge in the battery for normal operation of the key.
With this security system, when you get into the car, the key fob will tell the car that its owner is in it, so the engine can be started using the stop-start button.
