Ford P1231 OBD-II Trouble Code Definition: P1231 High Speed Fuel Pump Relay activated P1231 Ford OBD-II Trouble CodeDescription: OBD Trouble Code P1231 High Speed Fuel Pump Relay activated Sorry no other information,Please help us to improve,Any information is appreciated.Thanks. OBD Trouble Code P1231 Injector Circuit Cylinder 4 Intermittent Sorry no other information,Please help us to improve,Any […]