Troubleshooting Guide for Installing Dension Products22C. USB compatibilityFlash Memory and Hard Disk DrivesFile system: FAT32Storage capacity: up to 256 GB of music contentMusic format: MP3 MPEG1 Layer 3 : 32; 44,1; 48 kHz (32 - 320kbps); MPEG2 Layer 3 : 16; 22,05; 24 kHz (8 - 160kbps); MPEG2.5 Layer 3 : 8; 11.025; 12 kHz (8 -160 kbps) from 96 kb/s to 320 kb/s; MP3 Variable Bit Rate (VBR) (up to 320kb/s). WMA 4 - 44.1 kHz at sample rates up to 320 kb/s. Except for DRM protected files. WAV (16 bit, uncompressed PCM)We recommend the use of branded USB drives (TDK, Kingston, Sandisk, Transcend etc.).D. Firmware updateWe constantly improve our firmware, so it is highly recommended to perform a firmware update first,if an issue/problem arises. The update procedure on Gateway Pro BT is quite simple.Go to our website => Support => Downloads => Firmware update and make a filtering on Gateway ProBT using the dropdown menu, choose the latest firmware and download it.Extract the G31B_UPD.rom file from the update package, copy the file to the root folder on a USB flashdrive, connect the USB drive to the Gateway Pro BT while it is powered up (ignition ON). Copy a fewplayable music files to the USB device, to the root folder also. If there is an iPod connected to Gateway,please disconnect it before connecting the USB drive.The update procedure will start automatically within a few seconds and takes approximately 2minutes. During the update procedure the Gateway Pro BT will restart a couple of times. Do notdisconnect the USB drive or turn the ignition OFF (!).When finished, you may need to select the Gateway again as source from the Head Unit (car stereo).After a successful update the G31B_UPD.rom is deleted from the USB flash and the new softwareversion number will be visible in the Gateway Settings\About menu.Test the Gateway Pro BT functions.Please note: Although we do support playing music content from a USB hard disk drive, for thefirmware update please use a USB drive.Important note for Peugeot or Citroen users: Start the engine before performing a firmware updatein order to avoid the activation of ‘Economy mode’.