Before clicking on the link please read the instructions below on how to update your KNA-G520/G421.

To update to the latest version of firmware please click on this link

To Download software from Website

1.  Click on the link above and then select relevant model.

2. Agree to licence terms

3. Click on “Download”, then “save” to your desktop (do not change the filename)

Transfer to SD card

1. Insert blank SD memory card into computer (or card reader)
NB: Windows will assign a name such as: Removable Disc (H):
2. Create a new folder on this card called: garmin

To do this:

• Double click on your “My Computer” icon on your desktop
• Double click on the Removable Disc which relates to your SD card (eg: Removable Disc (H):)
• Click on “File”, then “New”, then “Folder”
• Rename the folder: garmin (NB: must be in lower case)

3. Find the file on your desktop which you downloaded and double click it
4. Then Click on “Run”
5. Click on “Browse”, find your new garmin folder, left click on it so that it is highlighted and then press “OK”
6. Click on “Unzip” and a new file called “gupdate.gcd” will be created within your garmin folder
7. Safely remove the SD card from your computer/card reader

To do this: 

• Click on the “safely remove hardware” icon (one of the small icons next to the clock on your monitor)
• Click on “Safely remove USB mass storage device”
• NB: if you get the message that Windows cannot remove the device, try closing Windows Explorer and try again

8. You can now physically unplug the card from your computer/card reader

Transfer to navigation unit

1.  With ignition off, insert SD card into slot on navigation unit
NB: the contacts on the card should be facing upwards (upside down)
2. Switch on ignition and follow on-screen instructions
3. The new software is uploaded from the SD card
4. Ignition off and remove SD card