The P0063 refers to “HO2S Heater Control Circuit Low Bank 2 Sensor 3,” indicating an issue with the heating element circuit of the oxygen sensor located in Bank 2, Sensor 3. This sensor’s heater circuit is crucial for bringing the sensor up to operating temperature quickly, ensuring accurate readings of exhaust gases.
When this circuit reports a low output, it can lead to various performance issues, including poor fuel economy, hesitation, rough idle, stalling, and power loss. Addressing this problem is key to maintaining engine efficiency and emission control.
P0063 quick overview
Meaning | P0063: HO2S Heater Control Circuit Low Bank 2 Sensor 3 |
Is it serious? | Yes, as it affects the engine’s fuel efficiency, emissions, and overall performance. |
Possible causes | – Damaged or corroded wiring and connectors – Faulty oxygen sensor heater – Issues with the Engine Control Module (ECM) or Powertrain Control Module (PCM) – Poor electrical connections or grounding issues |
How to diagnose? | Check for proper power and ground at the oxygen sensor connector. Verify continuity of the heater circuit in the wiring harness. Inspect the ECM or PCM for any faults that could affect oxygen sensor heater control. Test for excessive resistance in the heater circuit to confirm it’s within the manufacturer’s specifications. |
P0063 Meaning
When the P0063 code appears, it’s indicating that the electrical circuit that heats one of your car’s oxygen sensors isn’t working as it should, specifically signaling that the voltage in this circuit is too low. This heater is essential for the sensor to work correctly, as it needs to be at the right temperature to accurately measure exhaust gases.
If this circuit has problems, you might notice your car isn’t running smoothly, uses more fuel, or even stalls. Fixing this typically involves checking the sensor’s electrical connections, making sure it’s getting the right amount of power, and sometimes fixing or replacing the sensor or parts of the vehicle’s electrical system.

Car Diagnostics Training
- Car Electrical basics
- OBD-II scanner basics
- How to use an OBD reader
- Introduction to a Bi-directional Scan tool
- OBD scanner buyer’s guide + discounts
How to fix P0063 – learn from mechanics
I looked into P0063 service cases at iatn.com website where in the private forums the mechanics seek advice from other mechanics. I looked up a bunch of cases to help you decide how to fix your issue and see what would a real mechanic do to solve it.
Case #1: Dodge P0063
Vehicle information 2015 Dodge Charger 3.6L V6
Issue + repair history
- MIL lamp illuminated with code P0063
- Replaced Bank 2 Sensor 3 (downstream oxygen sensor)
- Checked wiring harness for damage or corrosion
- Code P0063 persisted after sensor replacement
- Engine experiencing poor fuel economy and occasional hesitation
Other OBD2 Codes + Test Results
- P0063: HO2S Heater Control Circuit Low B2S3
- No other codes reported
- Live data showed unstable oxygen sensor voltage during operation
Mechanic suggestions
- Check for proper power and ground at the sensor connector
- Verify continuity of heater circuit in the wiring harness
- Inspect PCM (Powertrain Control Module) for faults related to oxygen sensor heater control
- Test for excessive resistance in the heater circuit using a multimeter
Final fix
- Discovered damaged wiring at the oxygen sensor connector
- Repaired wiring, cleared codes, and reset PCM, resolving the issue
Case #2: Chevrolet P0063
Vehicle information 2016 Chevrolet Silverado 1500 5.3L V8
Issue + repair history
- MIL lamp illuminated with code P0063
- Replaced Bank 2 Sensor 3 (downstream oxygen sensor)
- Inspected wiring harness for damage or corrosion
- Code P0063 persisted after sensor replacement
- Engine experiencing rough idle and occasional stalling
Other OBD2 Codes + Test Results
- P0063: HO2S Heater Control Circuit Low B2S3
- No other codes reported
- Live data showed unstable oxygen sensor voltage during operation
Mechanic suggestions
- Check for proper power and ground at the sensor connector
- Verify continuity of heater circuit in the wiring harness
- Inspect ECM (Engine Control Module) for faults related to oxygen sensor heater control
- Test for excessive resistance in the heater circuit using a multimeter
Final fix
- Discovered corroded terminal at the ECM connector for Bank 2 Sensor 3
- Cleaned and repaired terminal, cleared codes, and reset ECM, resolving the issue
Case #3: Ford P0063
Vehicle information 2017 Ford Explorer 3.5L V6
Issue + repair history
- MIL lamp illuminated with code P0063
- Replaced Bank 2 Sensor 3 (downstream oxygen sensor)
- Checked wiring harness for damage or corrosion
- Code P0063 persisted after sensor replacement
- Engine experiencing loss of power and occasional misfires
Other OBD2 Codes + Test Results
- P0063: HO2S Heater Control Circuit Low B2S3
- No other codes reported
- Live data showed unstable oxygen sensor voltage during operation
Mechanic suggestions
- Check for proper power and ground at the sensor connector
- Verify continuity of heater circuit in the wiring harness
- Inspect PCM (Powertrain Control Module) for faults related to oxygen sensor heater control
- Test for excessive resistance in the heater circuit using a multimeter
Final fix
- Discovered damaged wiring at the oxygen sensor connector
- Repaired wiring, cleared codes, and reset PCM, resolving the issue
How to diagnose P0063
I made you an overview of solving this DTC, based on all the advice that was suggested by certified mechanics to address this issue in previously mentioned service cases.
Diagnostic Step | Explanation |
---|---|
Check for proper power and ground | Ensure the oxygen sensor’s electrical connections are secure and receiving the correct voltage. |
Verify continuity of the heater circuit | Test the heater circuit with a multimeter for any open circuits or shorts that could cause low voltage. |
Inspect the ECM or PCM | Check for any issues with the vehicle’s computer system that might impair the sensor’s heater operation. |
Test for excessive resistance | Measure the resistance in the heater circuit to ensure it does not exceed the manufacturer’s specifications. |

Car Diagnostics Training
- Car Electrical basics
- OBD-II scanner basics
- How to use an OBD reader
- Introduction to a Bi-directional Scan tool
- OBD scanner buyer’s guide + discounts

Hi, I am Juraj “Yuri” Lukacko. I got frustrated by unhelpful and scammy mechanics, so I decided to learn everything about car diagnostics myself. I test dozens of new car diagnostic tools every month along with learning new strategies to fix and customize cars. About Juraj Lukacko (Yuri)