IMPORTANT: Not all car stereo receivers have USB capabilities. To see if your car stereo has the USB function described in this solution, check the specifications or supplied manuals.
Some USB devices need to be switched into a specific mode, such as a mass storage class mode, player mode, or another connection mode before the USB device can be used for playback. Make sure that your device is set to the required mode before connecting it to the car stereo.
NOTE: To see how to switch the USB device into different modes, check the specifications on the device or contact the manufacturer of the connected USB device for further assistance.