The OBD2 code P0064 indicates an issue with the “HO2S Heater Control Circuit High Bank 2 Sensor 3,” suggesting that the heater circuit of the downstream oxygen sensor on Bank 2 has a voltage higher than expected.
This sensor plays a crucial role in monitoring the exhaust gases and adjusting the fuel-to-air ratio to maintain efficient combustion. A high voltage in the heater circuit can lead to engine performance problems, such as rough idling, hesitation, loss of power, poor fuel economy, and intermittent stalling.
P0064 quick overview
| Meaning | P0064: HO2S Heater Control Circuit High Bank 2 Sensor 3 |
| Is it serious? | Yes, this issue can impact engine performance and emissions, leading to rough operation and inefficiency. |
| Possible causes | – Short circuits in the wiring or connector – Faulty oxygen sensor heater – Problems with the Engine Control Module (ECM) or Powertrain Control Module (PCM) – Damaged or corroded wiring and connectors |
| How to diagnose? | Verify proper power and ground at the oxygen sensor connector. Check continuity of the heater circuit in the wiring harness for shorts. Inspect the ECM or PCM for any faults that could affect oxygen sensor heater control. Test for short circuits in the heater circuit using a multimeter. |
P0064 Meaning
When you see a P0064 code on your vehicle, it means there’s a problem with the electrical circuit that heats up one of the oxygen sensors in your exhaust system. Specifically, this code points to the circuit having too high of a voltage, which can mess with the sensor’s ability to accurately measure exhaust gases.
This can cause your engine to run poorly, use more fuel than necessary, or even stall out. Fixing this problem usually involves checking the electrical wiring for any damage or shorts, ensuring the oxygen sensor itself isn’t faulty, and sometimes correcting issues within the car’s computer that controls the sensor.
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How to fix P0064 – learn from mechanics
I looked into P0064 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: Ford P0064
Vehicle information 2018 Ford Mustang 5.0L V8
Issue + repair history
- MIL lamp illuminated with code P0064
- Replaced Bank 2 Sensor 3 (downstream oxygen sensor)
- Checked wiring harness for damage or corrosion
- Code P0064 persisted after sensor replacement
- Engine experiencing rough idling and occasional hesitation
Other OBD2 Codes + Test Results
- P0064: HO2S Heater Control Circuit High (Bank 2 Sensor 3)
- No other codes reported
- Live data showed stable oxygen sensor voltage during operation
Mechanic suggestions
- Verify proper power and ground at the sensor connector
- Check continuity of heater circuit in the wiring harness
- Inspect PCM (Powertrain Control Module) for faults related to oxygen sensor heater control
- Test for short circuits 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 P0064
Vehicle information 2017 Chevrolet Camaro 3.6L V6
Issue + repair history
- MIL lamp illuminated with code P0064
- Replaced Bank 2 Sensor 3 (downstream oxygen sensor)
- Inspected wiring harness for damage or corrosion
- Code P0064 persisted after sensor replacement
- Engine experiencing loss of power and poor fuel economy
Other OBD2 Codes + Test Results
- P0064: HO2S Heater Control Circuit High (Bank 2 Sensor 3)
- No other codes reported
- Live data showed stable oxygen sensor voltage during operation
Mechanic suggestions
- Verify proper power and ground at the sensor connector
- Check continuity of heater circuit in the wiring harness
- Inspect ECM (Engine Control Module) for faults related to oxygen sensor heater control
- Test for short circuits 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: Dodge P0064
Vehicle information 2019 Dodge Challenger 6.4L V8
Issue + repair history
- MIL lamp illuminated with code P0064
- Replaced Bank 2 Sensor 3 (downstream oxygen sensor)
- Checked wiring harness for damage or corrosion
- Code P0064 persisted after sensor replacement
- Engine experiencing intermittent stalling and rough running
Other OBD2 Codes + Test Results
- P0064: HO2S Heater Control Circuit High (Bank 2 Sensor 3)
- No other codes reported
- Live data showed stable oxygen sensor voltage during operation
Mechanic suggestions
- Verify proper power and ground at the sensor connector
- Check continuity of heater circuit in the wiring harness
- Inspect PCM (Powertrain Control Module) for faults related to oxygen sensor heater control
- Test for short circuits 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 P0064
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 |
|---|---|
| Verify proper power and ground | Ensure the oxygen sensor is correctly connected to the vehicle’s power supply and grounded. |
| Check continuity of the heater circuit | Test the wiring for any short circuits that could cause the voltage to spike above normal levels. |
| Inspect the ECM or PCM | Look for potential malfunctions in the car’s computer that might lead to incorrect heater operation. |
| Test for short circuits | Use a multimeter to identify any short circuits in the heater circuit, which could cause high voltage. |
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
I test OBD-II scanners and make DIY Engine diagnostics guides to help you solve your car problems without having to depend on the mechanic. A lot of them will try to scam you or are just no help at all. About Juraj Lukacko