DTC U0121: F-CAN Malfunction (Powertrain Control Module (PCM)-ABS): General Description

The car area network (CAN) transmits/receives pulsing signals to/from the control modules simultaneously by using two signal lines (CANH and CANL).

When the information is not sent from the ABS modulator-control unit through the F-CAN and this condition continues for a settled time or more or when the information sent from the ABS modulator-control unit is abnormal and this condition continues for a settled cycle or more, the powertrain control module (PCM) detects a malfunction and a DTC is stored.