P0543 Ford

Ford P0543 OBD-II Trouble Code Definition:

P0543 Intake Air Heater Incorrect Voltage

P0543 Ford OBD-II Trouble CodeDescription:

OBD Trouble Code P0543
Intake Air Heater “A” Circuit Open
What does the code mean? OBD-ii Code P0543 definition:
The engine control module (ECM) uses an intake air heater (IAH) to warm the incoming air for proper cylinder combustion. The ECM grounds the control coil of the IAH relay to energize the heater during cold operation. The ECM sends a bias voltage on diagnostic circuits one and two. If this voltage is not pulled low when the relay is OFF, or is high with the relay ON, DTC P0543 will set. The ECM will only store info on first failure, It triggers the SES light on the second failure.
Symptoms Sumptoms of OBD code P0543
– Engine Light ON (or Service Engine Soon Warning Light)
Causes Causes of the OBD-II code P0543
– Inatake air heater circuit open or shorter – Faulty intake air heater relay – Faulty intake air hearter