Car

How to start a car when the smart key has a problem

Phan Van Hoa September 13, 2025 07:03

Smart keys bring convenience when using a car, but sometimes they can "misbehave" and make you unable to start the car. Below are simple and effective ways to handle this problem.

Today's cars are increasingly equipped with advanced technology, from large screens that support Apple CarPlay to dashboards that integrate a series of modern features. These utilities make driving more convenient and comfortable.

However, that convenience also comes with some risks, especially in unexpected situations. If in the past, a traditional mechanical key could unlock and start the car regardless of whether the battery was still alive or dead, with a smart key, things are more complicated.

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Illustration photo.

Smart keys work based on radio signals, similar to Bluetooth connectivity, allowing data exchange between the key and the vehicle's electronic system. When you are within range, the vehicle automatically receives commands to unlock or allow the engine to start.

Some models even allow you to simply touch the door handle to open it when the key is nearby. This is a huge step forward in convenience, eliminating the need to fumble around in your pocket or purse for your keys.

However, the problem arises when the battery in the smart key suddenly runs out. At this time, the car will not be able to recognize the signal as usual, making it easy for you to fall into an awkward situation.

Fortunately, manufacturers have anticipated this scenario and built in a number of safety measures, so that even if your smart key runs out of battery, you can still open the doors and start the car in a number of special ways.

What to do when smart key has problem?

When your smart key fails or stops working, it's important to have a backup plan in place to avoid getting stuck outside your vehicle.

Experts recommend that drivers always carry some emergency items in their car, such as a car phone charger in case the phone runs out of battery, a mini tire pump to deal with flat tires, and especially a spare key.

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The type of battery commonly used for smart keys. Photo: Internet

Carrying an extra set of coin-cell batteries, such as the CR2032 or CR2025 type commonly used in smart keys, is also a smart choice, as you can replace them as needed. However, this is only possible if you are already in the car.

In the event of being locked out, the first thing you should check is whether your smart key has a built-in physical key. Many car manufacturers include a small slot or sliding mechanism on the key, hidden inside a physical key that can be used to open at least one door. Some cars even allow this physical key to operate the ignition system, allowing you to start the car in an emergency.

Also, just in case, you should leave a spare key with a trusted relative or friend, or keep it in a safe place that you can easily access when needed. This preparation will help you avoid getting stranded and be able to continue your journey smoothly.

Other ways to lock, unlock, and start your car

In case your smart key battery runs out, don't worry too much because many car manufacturers have built-in backup plans to help drivers continue using their cars. Depending on the brand and model of car, you can still unlock and start the car in simple ways.

For example, Hyundai instructs users to simply hold the brake pedal while pressing the electronic key directly onto the vehicle’s start button instead of pressing it manually. This mechanism allows the vehicle to recognize the key even if the battery is dead.

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A simple but effective way when the smart key runs out of battery is for the user to simply hold the brake pedal while pressing the electronic key directly on the car's start button instead of pressing it manually. Photo: Internet

Some manufacturers opt for a hidden slot for the key fob. Ford, for example, has these spare slots in the cup holder, center console, or right on the steering column. Once the key is in place, you can simply press the start button to get the car running. This ensures that you won’t be stranded even if the key fob loses power.

In addition, many modern car models are also supported by genuine mobile applications, allowing users to lock, unlock, and even start the car remotely via an Internet connection.

Especially with electric vehicles, this feature is becoming more popular and useful, making it easy to start the car to move to the nearest store to buy a replacement battery. These solutions show that car manufacturers are increasingly focusing on convenience and safety, ensuring that users always have a backup plan in any situation./.

Phan Van Hoa