DTC U0121: Lost Communication with the Anti-lock Brake System (ABS) Control Module: Description

WARNING: This page is about a different car, the 2012 Ford Pickup. However, it is still accessible from the selected car via links, so may be relevant.

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

DTC U0121:00 (Lost Communication with the Anti-lock Brake System (ABS) Control Module: No Sub Type Information) - This DTC sets when communication between the PSCM and the ABS module fails. The ABS module sends the following messages to the PSCM: Wheel speed, lateral acceleration and actual steering angle. If one or more of these messages is missing for more than 5 seconds and the PSCM has not set DTC U0001:88, the PSCM sets DTC U0121:00.