P0052: Oxygen (A/F) Sensor Heater Control Circuit High (Bank 2 Sensor 1)

What Does The P0052 Code Mean?

A P0052 DTC (diagnostic trouble code) refers to the O2 sensor (oxygen sensor) located on Bank 2in front of the catalytic converter. There is also an oxygen sensor behind the converter which is Sensor #2. Bank 2 is the side of the engine that doesn’t contain cylinder #1.

This O2 sensor #1 may also be refered to as an air/fuel ratio sensor since on some vehicles it is. The sensor detects the amount of oxygen in the exhaust gas compared to the outside air and then vehicle’s computer adjusts the air/fuel ratio going into the engine. The sensor is less effective when the exhaust gas temperature is low, so it includes a heater which is activated to help get better readings from the O2 sensor.

Essentially this P0052 code means that the resistance of the heater circuit is higher than normal. In some cases, that resistance level must be higher than 10 A to trigger the DTC code.

Note, this code is very similar in nature to P0031, P0032, and P0051

What Are The Symptoms Of The P0052 Code?

Most likely you’ll not notice any symptoms other than the MIL (malfunction indicator lamp, a.k.a. the check engine light) will illuminate.

What Are The Potential Causes Of The P0052 Code?

A P0052 DTC trouble code may be caused by one or more of the following:

• A short in the heater circuit in the sensor
• A failed O2 sensor heater
• Wiring/connectors broken/frayed leading to sensor and/or relay
• Failed PCM/ECM

How Can You Fix The P0052 Code?

To fix a P0052 DTC code, you’ll need to do a proper diagnosis. To do that, you’ll want to inspect the wiring and connectors leading to the sensor. Also if equipped with a heater relay and fuse, you’ll want to check those as well. Use a digital volt ohm meter to:

• Check for 12 volts at the heater circuit feed (hint: unplug the sensor and check at the wiring connector to do this measurement)
• Check the ground circuit for continuity
• Measure the resistance of the heater circuit (done on the sensor itself)
• Measure the resistance and voltage of the wiring

Refer to a service manual for the correct specifications (volts, ohms) for your vehicle. On some Toyota vehicles this code is triggered when the resistance of the heater circuit is above 10 A.

With that said, a common fix for this DTC is to replace the air/fuel (O2 oxygen) sensor #2 on bank 1.

Please keep in mind that OEM (original equipment) replacement sensors are recommended (from the dealer). Aftermarket sensors can be less reliable and of poorer quality (not always, but more often). There’s also a chance that replacement parts for the P0052 code may also fall under a federal emissions warranty (check with your dealer to see if it’s covered).

Recommended Parts

Below are some recommended auto parts to help you address the trouble code affecting your vehicle and get it running smoothly again:

>>> O2 Sensor
>>> WORKPRO 582-piece Crimp Terminals, Wire Connectors, Heat Shrink Tube, Electrical Repair Kit
>>> Dorman 86689C 399 PC Automotive Electrical Repair Kit
>>> ECU
>>> KAIWEETS Digital Multimeter

Note: During the purchasing process, please check carefully whether the part you want to buy fits your car!

Check This Video For Reference

Reference Sources

Diagnostic Trouble Code (DTC) Guide for P0052 – Ominitek Advanced Technologies, pages 25-26.