Why can't the car key unlock the car even though it has power?

[SanDerek]

The reason may be that the key's transmitter is damaged or the key's matching code has failed. Here is the relevant information: 1. Transmitter damage: It may be that the transmitter in the car key is damaged. The best way to check this is to use the spare key. If the spare key can start the car, it means the transmitter in this key is damaged. In this case, you may need to visit a 4S store to get a new car key. 2. Receiver damage: The reason may be that the car's receiver is damaged. If neither the regular key nor the spare key can unlock the car, it is likely that the car lock's receiver has a problem. You should go to a 4S store for repair as soon as possible.