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

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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 U0121:00 (Lost Communication with the Anti-lock Brake System (ABS) Control Module: No Sub Type Information) - This DTC is set when communication between the PSCM and the ABS module fails. The ABS module sends a steering angle sensor message to the PSCM. If this message is missing for more than the allotted amount of time and the PSCM has not set DTC U0001:88, then the PSCM sets DTC U0121:00.