P1642 P1642 OBD Code Definition: P1642 FC Relay 2 And 3 Control Circuit P1642 OBD Code Description: OBD Code P1642 FC Relay 2 And 3 Control Circuit OBD Code P1642 Non Immobilizer ECU Equipped OBD Code P1642 Fuel pump monitor circuit High input OBD Code P1642 Please check DTC Memory of Airbag ECU