Ford P0540 OBD-II Trouble Code Definition: P0540 Intake Air Heater Feedback Circuit P0540 Ford OBD-II Trouble CodeDescription: OBD Trouble Code P0540 Intake Air Heater “A” Circuit What does the code mean? OBD-ii Code P0540 definition: Symptoms Sumptoms of OBD code P0540 – Engine Light ON (or Service Engine Soon Warning Light) Causes Causes of the OBD-II […]