As a starting point it's worth checking that the USB drive you are using is the correct type and is correctly formatted. Toyota recommend a USB 2.0 device no larger than 32Gb and formatted to FAT32 or FAT16. We would also recommend putting the files in a sub-folder labelled 'Music' rather than just in the root directory. The maximum size of one file is 2Gb, so you may wish to adjust the compression format of your audio files to suit.

If this isn't successful and you have tried more than one USB drive, it may be an issue with the USB connector or the infotainment software. Depending on the age of your vehicle this can be done wirelessly or via a USB on older models, but this may require a visit to your dealer or an independent Toyota specialist.