What are the reasons for the smart key not being detected?

[VonLogan]

The reasons why the smart key cannot be detected: damage to the key's transmitter, damage to the car's receiver, damage to the door lock, or the battery in the key being dead. Generally, there are two types of keys with sensing functions: 1. Conventional folding mechanical keys; 2. Hidden mechanical keys. Basic components of a remote key: The system mainly consists of two parts: the transmitter and the receiver. The transmitter is composed of a transmission switch, transmission antenna, integrated circuit, etc., containing an identification code storage circuit and an amplitude modulation circuit, with a button-type lithium battery installed on the opposite side of the circuit. After the transmitter uses short-wave modulation to send out the identification code, it is received by the car's short-wave antenna and enters the short-wave high-frequency amplification processor of the receiver's electronic control unit through a distributor for demodulation, and then compared with the demodulator's identification code.

[Mallory]

I've been driving for over 30 years, and issues with smart key detection are quite common. The main cause is usually a minor problem, such as the button battery in the key running out of power—over time, insufficient voltage prevents the car from unlocking. From my own experience, first, check the key in sunlight to see if there's any moisture or dirt, and clean it if necessary. Another common issue is signal interference from a phone in your pocket—those things have strong magnetic fields, and keeping the key away from them usually fixes the problem. If none of that works, it might be an issue with the vehicle's detection zone, like a sensor in the door handle aging or short-circuiting, especially on humid days. It's best to take a spare key to a repair shop to check, just in case it's the car battery running low. Addressing it early brings peace of mind—don't wait until you're stuck in the garage. By the way, regularly replacing the key battery can save a lot of hassle; opt for a high-quality model for longer lifespan.

[VioletAnn]

When tinkering with cars, I've noticed that most smart key sensor failures stem from simple issues. First is the battery—replacing it with a new CR2032 or similar coin cell solves 90% of problems—just pop open the key's back cover and swap it in. If the issue persists after battery replacement, check if the key is properly paired with the car, as nearby interference sources like phones or wireless chargers can block signals. On the vehicle side, the sensor area near the door handle often becomes less responsive due to dirt buildup or moisture. A quick fix is rebooting the car system: turn off the engine for a few minutes and restart. For prevention, keep the key dry and avoid drops to save on repair costs. If all else fails, use the mechanical key as an emergency unlock workaround.

[VonRicardo]

Last time my new car key suddenly stopped working, which was really nerve-wracking. The reasons can be varied, such as the key battery running out of power—it usually needs replacement every two years. Or it could be because the key was too far from the car or there was a strong interference source in the environment, like being near large electrical appliances. You can try holding the key close to the driver's side door handle; sometimes restarting the door lock system helps. Remember to keep a spare car key at home in case of emergencies to avoid getting stranded. Regular maintenance is key—don’t delay replacing the battery.