P00D3 HO2S Heater Control Circuit Range/Performance Bank 2 Sensor 1

This code concerns the heated oxygen sensor upstream of the catalytic converter (sensor 1) on bank 2. Unlike the heater circuit codes, which report an open or short circuit, this code means the heater is driven but does not bring the oxygen sensor to the expected temperature. One documented method, used where no current-measuring shunt is fitted, measures the internal impedance of the sensor element: a hot element has a low impedance. If the impedance stays above a limit that depends on the calculated element temperature and the voltage at the sensor connector, the heating is judged insufficient. The test runs once per trip. Typical causes are an aged heating element or added resistance from corrosion in the heater circuit. For this sensor position no manufacturer description of the test was found; the code appears in a manufacturer's code list, and the explanation follows the documented counterpart for sensor 2. Bank 2 exists only on V and boxer engines.

Likely causes

Symptoms

• Check engine light on
• Usually no noticeable drivability problem
• Oxygen sensor heater readiness stays incomplete

Repair estimate

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

Related codes

References: law.cornell.edu, performanceparts.ford.com, newtonnet.co.uk.