DTC U0300: Internal Control Module Software Incompatibility: Action
WARNING: This page is about a different car, the 2010 Mercury Milan, 2010 Lincoln MKZ, and 2010 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.
RE-FLASH the PSCM software. Clear the DTC and repeat the self-test. If the DTC returns, install a new EPAS gear referring to STEERING GEAR -- 3.5L FRONT WHEEL DRIVE (FWD) , STEERING GEAR -- 3.5L ALL WHEEL DRIVE (AWD) or STEERING GEAR -- 2.5L NON-HYBRID AND 3.0L FRONT WHEEL DRIVE (FWD) .