DTC U0121: F-CAN Malfunction (Engine Control Module (ECM)/Powertrain Control Module (PCM)-ABS Modulator-Control Unit) (PGM-FI System): General Description

The controller area network (CAN) transmits/receives multiple signals to/from the multiple control modules simultaneously by using two signal lines (CANH and CANL). When the engine control module (ECM)/powertrain control module (PCM) does not receive the signals from the ABS modulator-control unit via the CAN lines for a set time, the ECM/PCM detects a malfunction and stores a DTC.