Guide to best firmware for MP3s off the USB drive?

Hello - I’ve been upgrading the firmware in my Ford Flex thanks to Cyanlabs’ and the comunity’s help for years, but I’ve run into some issues. I’m sure the newer firmware helps most people and solves most problems, but I feel like it isn’t working as well for me. I use my Sync3 system mostly to play music off my USB drive, and sometimes FM radio. I do most NAV stuff with Android Auto. The newer firmwares seem to screw with USB drive detection and suck with voice commands regarding music off the USB drive. Does anyone have a suggested “peak efficiency” version of the firmware when it comes to USB playback?

I’ve been slowly downgrading step by step here, but it is time-consuming and a tiny bit of guidance would go a long way.

SYNC Region: NA

Navigation Variant: Nav

Manufacturer Year: Pre MY20

Install Type: OEM

Old SYNC Version: 3.4.22200

New SYNC Version: 3.4.22200

Do you have a error message, if so what is it?

Update Method: CyanLabs Syn3 Updater

Syn3 Updater Version:

Syn3 Updater Documentation Read: yes

Syn3 Updater Log File


I would try 3.3.xxxx, available in the tool.
It’s not 3.4, but 3.4 has been known from the early builds to be a bit buggy when it comes to straight from USB playback. It’s gotten better in the last builds, but if you tried 3.4.21265 and still have issues, then you should try 3.3.xxxx.

Also, a clarification: lets not talk about firmware, because firmware is something else. What you are referring to is a sync3 version and build, not related to firmware.

This is to be expected as the newer Sync 3.4 versions past 3.4.19101 have been reducing support for older vehicles like the Flex with older CGEA architectures. The best bet is as @SaNdMaN suggests, use 3.3 or find a 3.4 version that is ok. Most likely 3.4.19101 or before will still work ok.

Upgrading Sync is not the same as upgrading Firmware/Calibrations FYI. 2016 Flex is the first year it came with Sync 3 so it is an older APIM and probably has the older USB hub. I would expect some issues as @F150Chief said it’s an older network.

You can use programs like Forscan to upgrade the APIM Firmware(Has limits) or you can buy a newer K series one that would run better.

Thanks for the advice - yeah I misspoke and confused firmware with Sync version. I’ve found with the newer versions of Sync that it now doesn’t always resume play off the USB drive when starting the car, nor does it always respond correctly to verbal commands asking for either artist or track names - it just starts doing NAV-related things.

I just wasn’t sure if there was a ‘sweet spot’ in terms of Sync versions when it comes to USB media.

I did replace the stock USB 2 hub with a Ford USB 3 hub several years back, since it was recommended for Android Auto stuff, but that shouldn’t negatively affect MP3 playback, should it?

Thanks so much for the help - I’ll completely reset and try 3.4.19101, then head deeper into downgrading if it doesn’t work. Appreciate the info!

My wife constantly complains about it doing this. No Sync version has fixed it but my other 2 cars don’t have this problem. I figure it is the USB drive itself in my case.

Do you any of you guys know if Focus 3 in South America is CGEA?.
I’m asking because here in Argentina most people had issues with USB playback on 3.4.
At least on early versions when it was new, Ford never got past 3.0 here.
But some have stated that on later builds the issue is less present, but present still.

To me, this was more related to 3.4 than the car itself.


Unless I am mistaken, it should follow the same gen Focus in other parts of the world being on a Global platform so it should be C1MCA like the rest.

That was my understanding, but I was a bit confused after reading that the USB playback issues may be related to architecture.


I’m closing this thread since we didn’t hear back from you in almost a week now, so I’m assuming no farther assistance is needed.