DTC U0100 Lost Communication with ECM/PCM A: Description

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 monitors the HS-CAN messages when the ignition has been on for more than 5 seconds, the voltage to the PSCM is greater than 6.5 volts and there are no DTCs present inhibiting PSCM operation.

DTC U0100:00 (Lost Communication with ECM/PCM A: No Sub Type Information) - This DTC sets if communications between the PSCM and the PCM fail. If the accelerator pedal position, engine speed, engine torque, transmission gear or vehicle speed message is missing for 1 to 5 seconds, this DTC is set.