Ford P0439 OBD-II Trouble Code Definition: P0439 Catalyst Heater Control Circuit Bank 2 P0439 Ford OBD-II Trouble CodeDescription: OBD Trouble Code P0439 Catalyst Heater Control Circuit What does the code mean? OBD-ii Code P0439 definition: The optical sensor provides a high resolution signal to the Powertrain Control Module (PCM) by counting pulses on the sensor disk […]