I encountered this issue when attempting to update the firmware for my car’s entertainment system, specifically the Ford Sync 3.4 system. The problem was that some USB thumb drives worked perfectly for the update, while others simply failed. After some investigation, I discovered that the root cause was the difference in the disk and partition setup of these drives.
The USB disk should show as (Active, Primary Partition) and not as (Basic Data Partition)
The key requirement for the firmware update is that the USB drive must be formatted as an MBR (Master Boot Record) disk rather than GPT (GUID Partition Table). This is a common compatibility issue because many embedded systems, like car infotainment systems, are designed to work with the older MBR partitioning scheme. This setup aligns better with traditional BIOS-style systems rather than newer UEFI-based systems.
- Open a cmd window as administrator
- Enter diskpart <enter>
- Enter list disk <enter>
- Now you see a list of the disks in your system, including the hard drive(s). Look for a disk with the size of your thumb drive. In my example it’s Disk 2 with a size of 3840 MB.
- Enter select disk 2 <enter> !!! USE YOUR USB’s DISK NUMBER, THIS IS NOT ALWAYS 2
- Enter clean <enter>
- Enter convert mbr <enter>
- Enter create partition primary <enter>
- Enter active <enter>
- Enter format fs=fat quick <enter> (you might need to format fat32 depending the size of your thumbdrive)
- Enter list disk <enter> You now should not see a * at the Gpt collumn
