Ford P0291 OBD-II Trouble Code Definition: P0291 Cylinder 11 Injector Circuit Low P0291 Ford OBD-II Trouble CodeDescription: OBD Trouble Code P0291 Cylinder 11 Injector Circuit Low What does the code mean? OBD-ii Code P0291 definition: Code P0291 is triggered when the Power Train Control Module (PCM) detects a low voltage in the Fuel Injector #11 Circuit. […]