I have a 2017 Ford Police Interceptor Utility (FPIU) throwing two error codes:
- FCDIM U0256:00-AF, Lost communication with Front Controls Module 'A'
- HVAC U0140:00-0A, Lost communication with Body Control Module
Symptoms include inoperative controls on radio and climate control, and no backlight on either.
Radio is defaulted to an AM station and I have to turn down the static using the volume control on the steering wheel, as the knob on the radio itself stopped working.
Heat is stuck on defrost and full heat, so I have to open the windows to cool the passenger compartment back down.
This all started after an alternator belt failed. After that was replaced, alternator was discovered to be overcharging (two different battery testers warned of high voltage with engine running, in excess of 15 volts) and also car battery would die overnight. After charging battery we could watch the voltage drop .1V/10 sec or so with key out. Suspecting a short we replaced alternator this morning, seems to have resolved that issue and voltage is stable with key out.
All blade-type fuses under dash and in fuse box by battery test OK, and the square J-type ones with windows visibly appear OK too.
Forscan BCM test doesn't reveal anything useful.
Tried leaving battery disconnected overnight, no change.
Any suggestions for anything else I can check?
