Ford P0643 OBD-II Trouble Code Definition: P0643 Sensor Reference Voltage A Circuit High P0643 Ford OBD-II Trouble CodeDescription: OBD Trouble Code P0643 Sensor Reference Voltage “A” Circuit High What does the code mean? OBD-ii Code P0643 definition: The ECM has detected that the 5 volt reference voltage is too high Symptoms Sumptoms of OBD code P0643 […]