Passat displays 'key not found'?
2 Answers
Passat displays 'key not found' for the following reasons: When there is electromagnetic interference with similar frequencies nearby, the vehicle's antenna cannot emit normal electromagnetic waves and fails to function properly. Therefore, even if the key is inside the car, it cannot be detected. The system will return to normal once the vehicle leaves the interference area. Working principle of keyless start: 1. There are multiple antennas inside the Passat that emit radio waves to search for the key. 2. When a valid key is detected, pressing the start button will allow the engine to start. If no valid key is found, starting will be prohibited and the system will display 'key not detected'.
I've encountered the issue of the Passat displaying 'key not found' several times. Having driven this model for five years, it's mostly due to low battery in the key fob. New keys typically last about one to two years before needing a replacement button battery, which can be easily solved by purchasing one on Taobao for just over ten yuan. Sometimes, external interference is the culprit—placing the key too close to phones or computers can block the signal. Try taking the key out separately and placing it on the center console to start the car, and the problem often disappears. Another possibility is that the key is dirty or worn; simply cleaning the contact points can help. My advice is to avoid mixing keys with electronic devices in daily use, as metal objects in the trunk can also cause interference. Regularly check the battery life. If none of these solutions work, it might be an issue with the vehicle's sensing system, requiring a visit to the dealership to connect a diagnostic tool and check for error codes. In short, don't panic—start with the simplest solutions. Ensuring driving safety is more important than anything else.
