Skip the auto shop - Our mechanics make house calls

P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)

Check Engine Light

P0052 code definition

HO2S Heater Control Circuit High (Bank 2 Sensor 1)

What the P0052 code means

This code is seen when the Engine Control Module (ECM) tries to control the heater control circuit for Bank 2 Sensor 1 and finds high voltage present. The heater is an integral part of sensor function that is used to heat the oxygen sensor to operating temperature until the vehicle warms up. Oxygen sensors must be at operating temperature to provide accurate readings to the ECM for air fuel ratio control. This code may be seen with P0051.

What causes the P0052 code?

  • Bank 2 Sensor 1 failure
  • Open or shorted wiring
  • Damaged or poor connections
  • ECM has failed
  • Oxygen sensor heater failure

What are the symptoms of the P0052 code?

The ECM checks for proper signals from all of the vehicle's sensors multiple times a second. When high voltage is found in the heater control circuit, the ECM triggers a Check Engine Light on the dashboard. In some circumstances, the vehicle may exhibit lower than normal fuel economy and run poorly.

How does a mechanic diagnose the P0052 code?

  • Hooks up a scan tool to the vehicle's OBD2 port to read live sensor data and check for any codes present

  • Uses the freeze frame data associated with every code to determine what conditions the vehicle was under when the code was set

  • Clears the code and performs a test drive with the scan tool hooked up to monitor sensor data and observe if the code returns

  • If the code returns, performs a visual inspection of all wiring and connectors in the circuit, to rule them out

  • Observes the oxygen sensor data stream to inspect sensor operation

  • If everything checks out this far, performs a manufacturer-specific test of the ECM (varies by make and model; no steps should be skipped.)

Common mistakes when diagnosing the P0052 code

P0052 can be a simple code to diagnose when all diagnostic steps are followed in the proper order and all tests are performed. A professional level scan tool that shows live sensor data will be required to properly diagnose any faults present.

How serious is the P0052 code?

The most common symptom is only the Check Engine Light being observed by the driver. In the chance that poor fuel economy or rough engine running is noticed, care should be taken when driving to ensure safety until the code can be diagnosed and repaired.

What repairs can fix the P0052 code?

Additional comments for consideration regarding the P0052 code

Any quality mechanic will own a scan tool capable of reading live sensor data.

When the heater circuit is found to have failed for the oxygen sensor, the sensor must be replaced. The heater is internal to the sensor and is replaced as a single unit.

Need help with a P0052 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.


Post a question and get free advice from our certified mechanics.


More related articles

Insurance Requirements for Car Registration in Kentucky
The Kentucky Transportation Cabinet requires that all drivers in Kentucky carry liability automotive insurance, or “financial responsibility” in order to operate a vehicle legally and maintain vehicle...
Veteran and Military Driver Laws and Benefits in Idaho
The state of Idaho offers a number of benefits and perks for those Americans who have either served in an Armed Forces branch in the...
P2422 OBD-II Trouble Code: Evaporative Emissions Control System (EVAP) Vent Valve Stuck Closed
Diagnostic Trouble Code (DTC): P2422 P2422 code definition Evaporative Emissions Control System (EVAP) Vent Valve Stuck Closed Related Trouble Codes: P2441: EVAP Vent Valve Stuck Open EVAP trouble...

Related questions

Q: Check Engine Light staying on

Your engine may need a tune up. Your engine, in addition to spark plugs and wires, also has a distributor cap and rotor that need to be replaced as part of a tune up. Commonly, over time, the metal parts...

Q: Unresolved leakage problems

Have the oil pressure tested to see if it is low, or the oil sensor is reading wrong. Also have the engine compression tested to see if the cylinder number 2 has a problem or not. The P0302 code...

Q: Problem with Check Engine light in my dashboard.

Hi and thanks for your question. The code P0139 means that the secondary oxygen sensor on bank 1 (the sensor after the catalytic converter) is not damaged, but rather the engine air fuel ratio is not being adjusted by the...