Body:
Hi everyone,
I need some technical advice regarding an issue with my Ford C-Max Hybrid (2017). I was using FORScan to activate several hidden features in the IPC and BCM modules.
What we successfully activated first:
Enabled Digital Speedometer on the instrument cluster.
Enabled Cruise Control Set Speed Display (shows exact target speed in digits).
Disabled Double Horn Honk when leaving the running car with the key.
Everything went smoothly during these configuration changes, and the new features worked perfectly.
After that, I decided to upgrade my Sync system from version 2.2 to version 3.4. Right after the update, I noticed that the lower control panel and the Ambient Lighting stopped working properly.
Current Symptoms:
The main Sync screen turns on and works fine, but the physical button panel below the screen does not light up
Ambient Lighting cannot change colors anymore.
Clock doesnot stay set
FORScan throws a network communication DTC: Lost communication between APIM and BCM.
APIM U0140
U0121
BDYCM B1399
What I have already tried to fix this (None of it worked):
Downgraded Sync: I flashed it back from 3.4 down to version 3.3, but the issue persists.
Hard Reset: Performed a hard reset on the modules via FORScan.
Battery Disconnect: Safely disconnected the 12V battery in the trunk (negative terminal first, then positive) to power cycle the system.
Fuses Checked: Inspected the fuses under the glove box (including F79 and F81), all are completely intact.
Research: I have read through dozens of forum threads online regarding this issue but couldn’t find a working solution.
It seems that the Sync 3.4 update somehow messed up the communication/gateway between the APIM and the BCM, causing the BCM to drop the FCIM panel and Ambient Lighting from the network.
Has anyone experienced this specific blackout after a 3.4 upgrade? Is there an As-Built parameter in the APIM or BCM that needs to be manually corrected to restore this communication link? I have my original As-Built backups ready.
Any help or guidance would be greatly appreciated!
And if i buy used screen and change it,will it solve my problem ?
Thanks!
SYNC Region: NA
Navigation Variant: Nav
Manufacturer Year: Pre MY20
Install Type: OEM
Old SYNC Version: 2.2
New SYNC Version: 3.3
Do you have a error message, if so what is it?
NO
Update Method: CyanLabs Syn3 Updater
Syn3 Updater Version: 2.0
Syn3 Updater Documentation Read: yes
Syn3 Updater Log File
CYANLABS - SYN3 UPDATER - V2.14.2.0
Branch: Stable
Operating System: Microsoft Windows 10 Pro (2009)
PREVIOUS CONFIGURATION
Version: 2.2.16280
Region: NA
Navigation: True
Install Mode: Автоопределение (reformat)
Install Mode Overridden: False
My20 Protection Enabled: Автоопределение
DESTINATION DETAILS
Mode: Drive
Model: WD easystore 2648 USB Device
Size: 931,5GB
FileSystem: exFAT
Partition Type: MBR
REFORMAT.LST
VOICE=5U5T-14G391-CS_1660783942000.TAR.GZ
GRACENOTES=4U5T-14G423-CC_1615429225000.TAR.GZ
APPS=NU5T-14G381-AE_1778770590000.TAR.GZ
AUTOINSTALL.LST
; CyanLabs Syn3Updater 2.14.2.0 Stable - reformat Mode - Sync 3.4.23188 NA
[SYNCGen3.0_ALL_PRODUCT]
Item1 = RWDataCleaner TOOL - PU5T-14G386-BB_1690840002000.TAR.GZ
Open1 = SyncMyRide\PU5T-14G386-BB_1690840002000.TAR.GZ
Item2 = REFORMAT TOOL - 1u5t-14g386-cb.tar.gz
Open2 = SyncMyRide\1u5t-14g386-cb.tar.gz
Options = AutoInstall
FILES (5)
1u5t-14g386-cb.tar.gz (8,5MB)
PU5T-14G386-BB_1690840002000.TAR.GZ (3,2KB)
5U5T-14G391-CS_1660783942000.TAR.GZ (385,5MB)
4U5T-14G423-CC_1615429225000.TAR.GZ (564,2MB)
NU5T-14G381-AE_1778770590000.TAR.GZ (869,9MB)
LOG
[30.06.2026 22:04:50] Selected Region: NA - Release: Sync 3.4.23188 - Map Version: 1.19 (2019) - NA
[30.06.2026 22:04:50] Install Mode: Автоопределение (reformat) Forced: False
[30.06.2026 22:04:50] MY20 Protection: Автоопределение
[30.06.2026 22:04:50] Formatting USB drive
[30.06.2026 22:04:50] Re-creating partition table as MBR and formatting as ExFat on selected USB drive
[30.06.2026 22:04:57] Checking Existing File: 1u5t-14g386-cb.tar.gz
[30.06.2026 22:04:57] Validated: 1u5t-14g386-cb.tar.gz (Skipping Download)
[30.06.2026 22:04:57] Checking Existing File: PU5T-14G386-BB_1690840002000.TAR.GZ
[30.06.2026 22:04:57] Validated: PU5T-14G386-BB_1690840002000.TAR.GZ (Skipping Download)
[30.06.2026 22:04:57] Checking Existing File: 5U5T-14G391-CS_1660783942000.TAR.GZ
[30.06.2026 22:04:58] Validated: 5U5T-14G391-CS_1660783942000.TAR.GZ (Skipping Download)
[30.06.2026 22:04:58] Checking Existing File: 4U5T-14G423-CC_1615429225000.TAR.GZ
[30.06.2026 22:04:59] Validated: 4U5T-14G423-CC_1615429225000.TAR.GZ (Skipping Download)
[30.06.2026 22:04:59] Checking Existing File: NU5T-14G381-AE_1778770590000.TAR.GZ
[30.06.2026 22:04:59] Validate: NU5T-14G381-AE_1778770590000.TAR.GZ (Failed!, Downloading)
[30.06.2026 22:04:59] Downloading: NU5T-14G381-AE_1778770590000.TAR.GZ
[30.06.2026 22:07:06] Validating: NU5T-14G381-AE_1778770590000.TAR.GZ
[30.06.2026 22:07:08] Downloaded: NU5T-14G381-AE_1778770590000.TAR.GZ
[30.06.2026 22:07:08] Preparing USB drive
[30.06.2026 22:07:08] Checking Existing File: 1u5t-14g386-cb.tar.gz
[30.06.2026 22:07:08] Copying: 1u5t-14g386-cb.tar.gz
[30.06.2026 22:07:08] Validating: 1u5t-14g386-cb.tar.gz
[30.06.2026 22:07:08] Copied: 1u5t-14g386-cb.tar.gz
[30.06.2026 22:07:08] Checking Existing File: PU5T-14G386-BB_1690840002000.TAR.GZ
[30.06.2026 22:07:08] Copying: PU5T-14G386-BB_1690840002000.TAR.GZ
[30.06.2026 22:07:08] Validating: PU5T-14G386-BB_1690840002000.TAR.GZ
[30.06.2026 22:07:08] Copied: PU5T-14G386-BB_1690840002000.TAR.GZ
[30.06.2026 22:07:08] Checking Existing File: 5U5T-14G391-CS_1660783942000.TAR.GZ
[30.06.2026 22:07:08] Copying: 5U5T-14G391-CS_1660783942000.TAR.GZ
[30.06.2026 22:07:12] Validating: 5U5T-14G391-CS_1660783942000.TAR.GZ
[30.06.2026 22:07:13] Copied: 5U5T-14G391-CS_1660783942000.TAR.GZ
[30.06.2026 22:07:13] Checking Existing File: 4U5T-14G423-CC_1615429225000.TAR.GZ
[30.06.2026 22:07:13] Copying: 4U5T-14G423-CC_1615429225000.TAR.GZ
[30.06.2026 22:07:18] Validating: 4U5T-14G423-CC_1615429225000.TAR.GZ
[30.06.2026 22:07:19] Copied: 4U5T-14G423-CC_1615429225000.TAR.GZ
[30.06.2026 22:07:19] Checking Existing File: NU5T-14G381-AE_1778770590000.TAR.GZ
[30.06.2026 22:07:19] Copying: NU5T-14G381-AE_1778770590000.TAR.GZ
[30.06.2026 22:07:26] Validating: NU5T-14G381-AE_1778770590000.TAR.GZ
[30.06.2026 22:07:28] Copied: NU5T-14G381-AE_1778770590000.TAR.GZ
[30.06.2026 22:07:28] Generating reformat.lst
[30.06.2026 22:07:28] Generating autoinstall.lst
[30.06.2026 22:07:28] ALL FILES DOWNLOADED AND COPIED TO THE USB DRIVE SUCCESSFULLY!