* The FM antenna is damaged. The FM antenna is typically located on the roof of your car. If it is damaged, it will not be able to receive FM radio signals. You can check the FM antenna by looking for any physical damage, such as a break in the wire or a loose connection.
* The FM tuner is not working properly. The FM tuner is the electronic component in your car radio that receives and decodes FM radio signals. If the FM tuner is not working properly, it will not be able to pick up FM radio channels. You can test the FM tuner by trying to tune in to a known FM radio station. If you cannot tune in to the station, the FM tuner may be faulty.
* There is too much interference. If there is too much interference in your area, it may be difficult for your car radio to pick up FM radio signals. Interference can be caused by a number of things, such as tall buildings, power lines, and other electronic devices. You can try to reduce interference by moving your car to a different location or by turning off any electronic devices that may be causing interference.
If you have tried all of the above and you still cannot pick up FM radio channels, you may need to take your car to a qualified mechanic or car audio technician for further diagnosis and repair.