Mazda cars often come with an immobilizer (the simplest security system) - immediately upon assembly. The device that controls it is built into the Mazda key block. This is extremely convenient for the car owner: there is no need to install an additional alarm system, all the keys are at hand, because they are part of a single key system, and you no longer need to carry anything with you to be sure that the car is in place and safe.
However, even with such a reliable security system, a number of unexpected things can happen. The most common of them is a dead battery in the control part. Replacing the Mazda 3 battery and key follows a simple and logical algorithm:
- Disassembling the key
- Removing the old battery
- Inserting a new battery
- Key assembly
The algorithm seems quite simple on paper, however, in order to successfully implement it, you need to know several important subtleties. For example, without knowing how to disassemble the key, it will not be possible to replace the battery. Therefore, we should talk about disassembling the key.
Mazda 3 chip key – device description
Almost all modern cars have some degree of protection against theft, and much better than those cars that were produced in the 90s of the last century. One of these levels of protection is considered to be the presence of a car owner with a chip key.
How does the Mazda 3 chip key work? As we know, the car’s ignition switch housing is located in a special frame, which is directly connected to the immobilizer electronic unit. When we turn the key in the lock, the electronic unit of the device transmits certain impulses to the ignition lock frame and the reading mode, invisible to the human eye, is activated.
The information reading mode is the response from a key equipped with a chip. Next, the following happens: thanks to the impulse, the chip key receives the necessary energy and transmits the code embedded in it to the immobilizer frame.
The frame, in turn, receives an encrypted code and, if it matches the factory settings, gives a kind of permission to start the power plant. After which the engine starts and there is no longer a need for the starting circuit.
Mazda CX-5 Key Fob Battery Replacement Guide - 2012 to 2021 Models
| This vehicle maintenance tutorial was specifically written to assist owners of the first generation (2012, 2013, 2014, 2015 and updated 2022 model year) Mazda CX-5 SUV in replacing the battery with a smart or smart keyless entry keyless entry and push start button engine system. Owners of other Mazda vehicles such as the Mazda2, Mazda3, Mazda5, Mazda6, CX-7, CX-9 and MX-5 Miata may also find these DIY instructions to be useful. Replaceable coin cell (AKA "button" or "clock") battery - part number CR2025 . The battery is available from various manufacturers such as Panasonic, GE, Sony, Maxell, Energizer and Duracell. The only tool required to replace the battery is a small flat head screwdriver used to separate the FOB key. | The first two steps are to remove the key fob from the key ring and any other keys. Then flip the keychain over and there is a small sliding tab. Slide the gray button to the other side of the key fob to release the emergency metal ignition key. Remove the metal ignition key and install it. in a safe place. Insert the blade of a small flat head screwdriver into the void (also known as a "slot" or "gap") where the metal key is used to position and neatly separate the two halves of the key fob. |
Signs of a Mazda 3 key problem
Reasons for engine start failure related to the immobilizer system and Mazda 3 chip key may be:
- malfunction of the native key chip; a dead battery in the key (if the chip has an autonomous power supply, in most cases the performance of the chip does not depend on the battery, since it is a small autonomous crystal placed in a ceramic case without any leads);
- breakage of the pumping loop or disruption of electrical connections to it;
- malfunction in the power supply circuits of the immobilizer unit;
- failure of communication between the immobilizer unit and the engine control unit; “failure” of the firmware of the engine control unit, immobilizer, which can be associated with a powerful electromagnetic pulse;
- malfunctions in the power supply of the engine control unit; an attempt to start the engine with a non-original key; discharge or disconnection of the battery terminals, especially when the ignition is on.
A large number of reasons why the Mazda 3 immobilizer system leads to failure to start the engine require a strictly defined algorithm (sequence of actions) to identify a specific faulty unit.
Remote control battery
The battery voltage of the remote control is 3 volts. You can use batteries from the following series: CR1620, ECR1620, DL1620, 5009LC, SB-T17. These are lithium cells with a diameter of 16 mm, a thickness of 2 mm, and a capacity of 68 mAh. The self-discharge of the element is no more than 1% per year, so they have a long shelf life - from 5 to 10 years. Remain operational at ambient temperatures from –30 to +85 °C. The battery life directly depends on the frequency of use of the key. Average duration of work: from 1 year to 2 years.
Do-it-yourself chip key repair for Mazda 3
One of the most common problems is the destruction of buttons (Mikrikov) on the key board. Buttons can become unusable over time, or a common situation is when the key body is cracked, and when you press the key button, the body itself is pressed through, and when you press the button, you come into direct contact with the button on the board.
In most cases, it is not possible to repair a chip key on a Mazda 3 yourself, since this procedure requires special skills and tools from you. Therefore, the recommendation of our website is that if the key chip breaks down, contact a specialist or purchase a new one.
Signs that the battery needs to be replaced
The remote control provides communication at a distance of up to 1 meter. The range of confident control of the door and trunk locks is within a radius of 80 centimeters from the external receivers located next to the locks. When the battery potential decreases, the driving distance is reduced.
When you have to move the remote control closer to the door handle every time you open the door, this is a sure sign of low battery power.
If the Advanced Key card battery is low, the green “KEY” icon will flash for 30 seconds after the starter button is pressed to turn the ignition off. The icon is located in the tachometer area on the vehicle's instrument panel. This signal serves as a warning that the battery needs to be replaced.
Note. The “KEY” indication can be disabled in the personal settings system. If the card is not detected, the indicator will turn red, one of the reasons is that the card’s battery is completely discharged.
If the car security system does not respond to pressing the remote control buttons. And at the same time, the activation indicator on the remote control itself does not light up. This is direct evidence that the battery is completely discharged.
How to replace the battery on a Mazda 3 chip key - step-by-step instructions
In order to independently replace the battery in the Mazda 3 chip key, follow the following procedure:
- The battery in the key is of the type CR2025, more or less normal brands like Panasonic, Energizer, Duracell for some reason, all Made in Indonesia. I chose the cheapest Panasonic of these three batteries; as it turned out, the exact same battery was originally inserted inside the key.
- Using a screwdriver, remove the back cover from the device's key fob.
- We take out the old battery and replace it with a new one.
- Closing the back cover
Well, that's basically all the instructions. I think everyone can handle replacing the battery in a Mazda 3 chip key.
Replacing the battery in the key remote control
To replace the battery, you need to separate the key from the remote control and disassemble the remote control housing. This can be conveniently done using a thin flat-blade screwdriver. You can use a penknife, an awl or a piece of steel wire. You should purchase a new CR1620 battery in advance.
Step-by-step instruction
- Reveal the key, free the niche it occupies.
- Using a thin screwdriver, press the latch located in the niche slot and separate the key from the remote control.
- In the opened end part of the remote control, insert a screwdriver into the gap between the cover and the case and, using it as a lever or turning it along the axis, separate the upper part of the case from the bottom.
- Remember the position of the battery in the slot relative to “+” if the corresponding mark is missing.
- Press out the plastic tab on the battery holder.
- Loosen the battery using a screwdriver and remove it from the case.
- Inspect the condition of the contacts on the board, if necessary, remove oxides and wipe with a soft cloth.
- Place the new battery in the socket and press it with your finger until the holder latch locks.
- Connect the two halves of the housing and squeeze them to secure the latches around the perimeter.
- Connect the remote control to the key and press firmly to secure the key latch.
- Check the functionality of the remote control.
Attention. The latches and latches, as well as the remote control body, are made of plastic. At low temperatures, plastic becomes brittle. To avoid damage to the latches, the remote control should be warmed up.
Choosing the right battery
From the factory, the immobilizer control system on the Mazda 3 is powered by a Panasonic CR1620 battery. However, such elements are produced by many companies, and in order to replace a failed element, finding one that matches the parameters is not difficult.
Before replacing the battery, you need to choose a new, more reliable one.
Basically, keys with an immobilizer use CR batteries. To replace the battery, it is better to look for a larger CR, as this indicates how long the mechanism will operate. However, a standard CR 1620 battery will do. Many brands have standard batteries marked CR, so purchasing one is not difficult. The unit comes standard with a Panasonic battery. If the reader is satisfied with the battery life of this company, then it makes sense to install it, especially since it has the lowest price in stores.
Recommendations from experts
In order for the galvanic cell to last as long as possible, you must adhere to the rules for charging and operating the battery. Charge only with a charger with a constant current of 10 A, observing polarity. After fully charging the battery, it is advisable not to use it for several hours.
The service life of a galvanic cell depends on the number of charge/discharge cycles. To reduce the rate of wear, you need to:
- do not expose the car to too high or low temperatures;
- turn off devices that consume a lot of energy;
- monitor direct and alternating voltage in the car;
- minimize cases of complete discharge of the element;
- do not let the car sit idle for a long time;
- keep the car locked.
Like any device, batteries are subject to external corrosion. Preventive cleaning of the surface of this element, as well as regular inspection to look for damage, will help preserve the body of the device. Traces of electrolyte leakage indicate a violation of its integrity and the need for repair or replacement.
Experts recommend wiping the body with a soda solution. It neutralizes acid and protects surfaces from corrosion.
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How to disassemble the key and change the power source
The first generation was produced from 2003 to 2008, the second began to be produced in 2009 and finished in 2013. Despite this, their key remained unchanged, so replacing the battery in the remote control is carried out according to the same scheme.
To disassemble the key fob, you need to press a shiny button of a rather impressive size - then the key will take its working position.
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Now you can begin the analysis. To do this, we find in the small niche formed after unfolding the key a button that secures the connection of the two halves of the key fob.
Attention. The latch that connects the two parts of the key fob is quite fragile, and therefore disassembly is best done in a warm place.
To split the key in half, use a screwdriver to press on this “pimply”.
Without fixation, the keychain easily separates into two parts. We put the top one with the key aside, and continue to work with the second one.
There are 2 grooves on it, into which you need to carefully insert a screwdriver and make a rotational movement. The bottom cover will come off.
Numerous instructions telling you how to change the power element indicate: just press one edge with your finger, and it will pop out like a jack-in-the-box. For some reason it didn’t work out for us, and we had to pry off one edge of the battery with a screwdriver. All that remains is to replace the expired element.
Now that we have introduced you to all the features of the battery replacement operation, you can easily perform it as needed. Assembly is carried out in reverse order.
Let's disassemble the key
You need to disassemble the key with a small tool. This could be an extra-small screwdriver or an awl. This is necessary in order to reveal the key. The standard key for Mazda opens and is divided into two parts: the key itself and the battery. The battery is always located in the second unit - the battery.
To open the battery, you will need a screwdriver or an awl. The tool must be pressed on the fixing element, which is usually located in the crevice on the side. The locking element is a lever in the form of a very small button that must be pressed.
When pressed, one half - the lid - will separate from the other. When the cover comes off, the inside of the key will be visible. There you can also see a battery and a number of other devices.
1. First of all, press the button so that the key opens. Take a screwdriver and press into the recess where the two parts of the key connect. Look closely and you will see something like a dark button inside the key. After pressing, the key will be disassembled into two parts.
2. Set aside the part of the key, the one with the Mazda emblem on it. Insert a flat-head screwdriver into the slot and apply a forward motion. Don't use too much force. As a result, the key block must be divided into two parts - with a microcircuit and a battery.
Mazda 3 disassembled key
3. We gained access to the battery compartment. Use a screwdriver to remove the battery, but before doing this, remember what position it is in. The Mazda 3 key uses a lithium battery with the popular CR1620 size. Unpack the battery and simply return it to the empty space, paying attention to the contacts. Now we perform the reverse steps: connect the disassembled parts, and then assemble the key together. Make sure the key is working.
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Watch the video on how to easily change the battery in your Mazda 3 key
Replacing the battery and reassembling the Mazda 3 key
Replacing the battery in the key is a fairly simple matter.
You need to press on the free edge of the battery, and then it will pop out of the power supply under pressure. However, sometimes there are difficulties even with this. There are users who write that they were unable to simply replace the battery, so they had to apply additional pressure to it using a crochet paperclip. Therefore, we change the battery very carefully and try not to break the additional modules. When replacing, it is necessary that the side with the positive marking (that is, the plus sign) is on the bottom, otherwise the key will not work. In this case, the battery information label will be on top.
Now you need to assemble the key body. This operation is done in the same way as parsing, but in reverse order. Therefore, the first step after installing the battery in place is to assemble the key body. This is done by simply pressing until you hear a click. A click will sound if the locking element is working correctly - in this case it will pick up the cover, and then the case will be intact. After this, you need to fold the two parts of the key - and then it will be assembled.
When the installation of the new battery in the key is complete, the key light on the instrument panel will stop flickering red. This will mean that the installation was successful and the key can be used for work.
Thus, installing a new battery in a Mazda 3 key is not a difficult task, but it is painstaking and requires certain skills. However, following these instructions, any driver of this car can do this easily and quickly. Basically, this type of work takes 10-20 minutes, depending on how the battery is mounted in the case.
Replacing the battery in the “Advanced Key” card
The Mazda manufacturer recommends changing the card's battery at a service station. However, it also allows for independent replacement. You can use the tools from the previous list.
Step-by-step instruction
- Slide the latch and remove the auxiliary key from the card.
- In the opened part of the end of the card along the edges there are two slots at the junction of the two halves of the case, where you should insert a screwdriver and, turning the screwdriver handle around the axis, disengage the plastic latches.
- Insert a screwdriver into the gap formed around the perimeter of the case and move it along the case on both sides, releasing the remaining latches.
- Remove the top cover, which contains the battery socket.
- By pressing the edge of the battery you can remove it from the socket.
- Insert the new battery “+” down.
- Connect the two halves of the card and squeeze until the latches lock.
- Insert the auxiliary key into place and close the latch.
- Check the functionality of the card.
Note. In the latest modifications of Mazda, the “Advanced Key” card has a different design. The battery is inserted from the end of the card. There is no need to disassemble the case. It is enough to remove the socket plug and pry off the battery with a sharp awl or needle.
