Diagnostic Aids
WARNING: This page is about a different car, the 2017 Ford F-150. However, it is still accessible from the selected car via links, so may be relevant.
The PSCM reporting only DTC B1D23:68 does not indicate a fault in the PSCM. It indicates an over-temperature condition due to ambient conditions or a heavy load on the EPAS system. An example of a heavy load would be multiple parking lot maneuvers over a short duration of time with low tire pressure or towing for long distances followed by multiple parking maneuvers.
The thermistor used by the PSCM is calibrated for 80°C (176°F) and as ambient temperature decreases, so does the accuracy of the sensor. At room temperature and lower, the sensor is +/-20°C (68°F).