DTC U0100: Lost Communication with ECM/PCM A: Description

WARNING: This page is about a different car, the 2019 Ford Fusion. 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 9 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 is set if communications between the PSCM and the PCM fail. The PCM sends 2 message bundles to the PSCM. If 1 or both of these messages is missing for more than 5 seconds and the PSCM has not set DTC U0001:88, then the PSCM sets U0100:00.