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Why Your Garmin or TomTom Sat Nav Isn't Recognising Your SD Card (Map Update Fix)

Quick Shortcut: Garmin and TomTom Sat Navs strictly require a FAT32-formatted microSD card up to 32GB. If you insert a 64GB or 128GB card, it comes formatted as exFAT and the Sat Nav will ignore it completely! Use a 32GB SanDisk Ultra card for instant plug-and-play map updates.

How to Get Your Sat Nav to Detect Your Memory Card Immediately

  1. 1. Use a 32GB microSD Card: Garmin officially specifies a maximum of 32GB (FAT32) for Drive, DriveSmart, Zumo, Camper, Dezl, and Nuvi map updates. A 32GB card comes pre-formatted as FAT32 straight out of the packet.
  2. 2. Insert Before Connecting to PC: Put the 32GB microSD card firmly into the Sat Nav slot BEFORE plugging the Sat Nav into your computer for Garmin Express or TomTom MyDrive updates.
  3. 3. Restart the Sat Nav: On TomTom units, power the Sat Nav fully off and back on with the 32GB card inserted—a message will appear asking 'Format memory card for maps?' Tap Yes.

Recommended Plug-and-Play Storage Picks

Plug & Play (Pre-Formatted FAT32)

SanDisk Ultra 32GB microSD / SD Card

Works straight out of the packet in Sat Navs, Trail Cameras, 3D Printers, and older devices that reject 64GB+ cards.

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