SD Card Reformat Garmin | How to reformat a secure digital (SD) card?

charlesd45's picture

Updated 6-29-18.

Before you begin the formatting process it is best to make sure your SD Card meets the correct specs and is not a fake.See this program that was brought to our attention by alandb . . H2testw is a simple tool that is distributed for free, does not require installation and offers a very simple, easy-to-use interface. The program can be used by anyone who wants to know how their product compares to others, or the amount of errors that can be detected on their device. Subject discussion can be found at .

The following instructions will explain how to reformat a secure digital (SD) card. Sometimes a microSD/SD card may require formatting before the card can be used with a Garmin device.

NOTE: These instructions are only for formatting a SD card and/or a microSD card. It is not recommended to format any Garmin Mass Storage device unless otherwise directed by Garmin Product Support. If the microSD/SD card is inserted into a Garmin Mass Storage device, e.g., a nuvi, the Garmin nuvi will show up as one drive. The microSD/SD card should show up as a separate drive. Make sure not to format the device, just the microSD/SD card.


To format a microSD/SD card:

1.Open Spotlight (CMD-SPACE on keyboard).
2.Type Disk Utility (in Spotlight search box).
3.Click Disk Utility to open the application.
4.Click the drive to format on the left side of the disk utility.
5.Click the parent of the SD card (it normally has the size in the name).
6.Click on the Partition Tab.
7.Under the Volume Scheme select "1 Partition". (OS 10.7 Lion this is called Partition Layout).
8.In the format area, select MS-DOS (FAT).
9.Click Options.
10.Select MBR (Master Boot Record).
11.Click OK.
12. In the Name field type a name/title for the SD card (Do not leave the name called "Untitled").
13.Click Apply to format the card.

On occasion some individuals running OS 10.6 may receive an error in the process. If an error occurs:

1.Click the Erase tab.
2.Select MS_DOS (FAT) from the format drop down.
3.Click Erase.
4.After the erase is complete follow steps 1-13 for formatting the card.


On Windows, make sure to format the microSD/SD card to a FAT or FAT32 format. A 2 GB or less card can be formatted in FAT or FAT32. Anything larger than a 2 GB should be formatted in FAT32.

For mass storage devices:

1.Place the SD card into the SD card slot in the device.
2.Go to This PC icon on desktop.
3.Locate the removable disk drive underneath the Garmin drive.
4.Right click on the SD data card drive.
5.Click on Format.

For media transfer protocol devices (MTP):

1.Remove the SD card from the device.
2.Place the SD card into a SD card reader (not the GPS device). This will allow the SD card to be seen in mass storage mode which allows formatting.
3.Go to This PC icon on desktop.
4.Locate the SD card as a removable disk drive.
5.Right click on the SD data card drive.
6.Click on Format.

If Windows does not offer the FAT32 option when attempting to format larger SD cards.POI Factory member alandb has provided the following process below.

You can format any SD card as FAT32 in any version of Windows using the Windows command prompt. All you need to do us include the File System switch /FS:FAT32 in the command. Here is an example:

After following these steps the microSD/SD should be readable by the Garmin device.

See also and .

Another reformatting program that POI Factory member canuk brought to my attention and that he highly recommends is called SD Formatter .It can be found at this link . The forum discussion started by Evert on this topic can be found at .

Change History

  • charlesd45 - Jun 29, 2018
    New information provided by alandb.Format any SD card as FAT32 in any version of Windows 6-29-18.

  • charlesd45 - Jul 26, 2015
    Information for H2testw provided by canuk on 7-26-15.