Hello, I’ve got a tricky issue with APIM that’s been really perplexing me.
（Since the time span has been quite long and many of the pictures are gone, I can only narrate it in words）
I drive a 2019 Ford Focus ST-Line (Chinese version). It didn’t come with in-built navigation from the factory. The original cruise mode was just cruise control, and it had the factory Sync 3.2 system. Later, I installed an ACC button and enabled the ACC function through reprogramming. For the next three years, there were no issues at all.
Over two months ago, I upgraded to a European-version full-LCD instrument cluster. Since the European cluster lacked the driver assistance and vehicle settings features, I had to upgrade to Sync 3.4-23188 and then reprogram the APIM configuration to unlock the hidden menus. Only then could the driver assistance and vehicle settings appear on the central control screen. However, after upgrading to 3.4-23188 and reprogramming the APIM configuration, the central control screen still didn’t display the complete driver assistance and vehicle settings menus（Some settings would show up, but once I entered the menus, the options were grayed out. For example, in the cruise settings, after clicking in, both cruise control and ACC were grayed out and unselectable）Then, I updated the APIM firmware using UCDS. The original APIM module part number was 3U5T-14G371-BEE, with a hardware code of 15T-14G380-CD. The original firmware file combination was GB5T-14G376-AA, 1U5T-14G374-AE, 1U5T-14G375-CA, GB5T-14G379-AA, and JB5T-14G379-FA. I replaced them with GB5T-14G376-AA, 1U5T-14G374-EM, 1U5T-14G375-HA, GB5T-14G379-AA, and 5U5T-14G379-BC. After reprogramming, I could normally configure the driver assistance and vehicle settings on the central control screen. But a new problem emerged: my keyless entry system stopped working. The door handles couldn’t unlock or lock the car. After unlocking with the key button and entering the car, when I pressed the power button to turn on the ignition, the instrument cluster indicated that the key wasn’t detected.
I suspected an issue with the BCM configuration, so I used Forscan to restore the BCM module’s configuration to its factory AB settings. This solved the key problem, but then the ACC stopped working. At the same time, I noticed that whenever I made any changes to the BCM configuration, my key would immediately become invalid. For example, if I could unlock or lock the car using the driver’s door handle, and then do the same with the passenger’s door handle, when I tried to unlock or lock the car again using the driver’s door handle, the key would become invalid. Or, when the keyless entry was working fine, after locking the car with the key button, the keyless entry would stop working.
After learning from this forum, I found that the calibration file 1U5T-14G375-HA is designed for European-version 64G vehicles with navigation and doesn’t match my vehicle. The suitable calibration file for my vehicle is 1U5T-14G375-CA. Could the guru please tell me if the issue with my vehicle is due to an error in the 1U5T-14G375-CA calibration file, which is causing abnormal communication between the APIM and BCM (so that the keyless entry and ACC can’t work simultaneously)? Or is it because the strategy file 1U5T-14G374-EM doesn’t match the 3U5T-14G371-BEE module?