Ford P0651 OBD-II Trouble Code Definition: P0651 Sensor Reference Voltage B Circuit Fault P0651 Ford OBD-II Trouble CodeDescription: OBD Trouble Code P0651 Sensor Reference Voltage “B” Circuit/Open What does the code mean? OBD-ii Code P0651 definition: These 5-volt reference circuits are independent of each other outside the PCM, but are bussed together inside the Engine Control […]