Issues with Updating my SYNC3 MY2018 from Version 3.3 to 3.4 (SIGN_ERR01)

Ford SYNC 3 Support CyanLabs Update Support
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1

Hey Guys,

I have trouble with updating my SYNC3. I tried many things: The first thing I tried was your SYN3 Updater (latest Version). Everything I tried (different computers, different USB-Sticks, different target-versions, with or without navigation, resetting my SYNC3 via settings) resulted everytime in SIGN_ERR01. The official Ford-Website does not know my current version so the update package I can download is an older version than the version, I currently have. I also tried manual Update, Reformat mode etc. → Same error message here.

It seems, that the USB-Port isn’t recognized correctly or it has banned by my SYNC3.
I guess there could be a problem with the european version of my Sync3 and I don’t know, what else I could do.
Do you have any ideas, what I can do now?
If you need some more information, screenshots or sth. else, let me know.

Many thanks!

Jens

SYNC Region: EU

Navigation Variant: Nav

Manufacturer Year: Pre MY20

Install Type: Unknown

Old SYNC Version: 3.3.18266

New SYNC Version: 3.4

Do you have a error message, if so what is it?
SIGN_ERR01

Update Method: CyanLabs Syn3 Updater

Syn3 Updater Version: latest

Syn3 Updater Documentation Read: yes

Syn3 Updater Log File

There is no logfile, because of the SIGN_ERR01 -> Nothing else happens.
2

Since you have no Syn3 Updater lof file it is difficult to guess what is going on, but you are obviously trying to update the maps also, as the Sync OS would not give this code.

Have you performed a master reset then performing the update?
Try updating the Sync version to 3.3.19052 and see if this works. You will only need the one file, nothing else.

3

Thanks a lot for answering!

I’m very sorry! Of course there is a log file of Syn3 Updater. I thought the log file, which the Sync3 System is writing to the USB-Device while the update process, was ment.

So I prepared a USB-Stick with the Version 3.3.19052 as you recommended.
Before I put the USB-Stick into the port, I performed a master reset.

WhatsApp Image 2026-02-18 at 18.49.07
WhatsApp Image 2026-02-18 at 18.49.071600×1200 108 KB

log-2026-02-18-18-31-04.txt (4.2 KB)

4

@F150Chief

I saw a youtube-video about the reformat utility from f-mods-forum. Looked like it could help.

Do you think, the reformat utility could help me, too or would it brick my sync3?

5

@F150Chief

Do you have any ideas, what I could do?

Is it maybe necessary to disconnect the battery for a while to ensure, the APIM’s cache is cleared or something like that?

6

Run the interrogator utility in the Syn3 Updater app and post the XML file here.

7

@F150Chief

I downloaded the logtool und put it on the usb-device.

I plugged the usb-device in and started the engine. Sync3 was starting, then I got the same error message (SIGN_ERR) and there was no xml-file on the usb-device after this.

What else could I do?