What does the P0063 fault code mean?
The P0063 fault code, applicable to all car manufacturers, means “HO2S Heater Control Circuit Low (Bank 2, Sensor 3)“.
Background information: The oxygen sensor measures the oxygen content in the engine exhaust to correct the fuel injection quantity, thereby achieving the optimal air-fuel ratio for the engine. In OBD fault codes, you will often see the oxygen sensor number specified. Bank 1 refers to the bank containing cylinder 1, and the remaining bank is Bank 2. Regardless of the bank, the first sensor always refers to the upstream oxygen sensor (before the catalytic converter), and the second sensor always refers to the downstream oxygen sensor (after the catalytic converter). The electronic control unit (ECU) maintains the oxygen sensor temperature at 780°C by controlling the on/off state of the oxygen sensor heater. This fault code will appear if the voltage in the heater control circuit falls below the calibrated minimum value.
Symptoms of Error Code P0063:
- The Check Engine light came on.
- Increased fuel consumption.
- Unstable engine operation.
- Increased emissions.
- Decreased acceleration.
Main Causes of Error Code P0063:
- Oxygen sensor malfunction (HO2S Bank 2 sensor 2).
- Damaged or broken sensor wiring.
- Console corrosion or poor contact.
- Short circuit in heater control circuit.
- Engine Control Module (ECM) malfunction.
Error Code P0063 in Different Vehicles:
P0063 in Toyota: It is usually related to sensor wear or wiring problems. In Toyota, the sensor may be hard to reach.
P0063 in Chevrolet: In Chevrolet models, the problem may be due to high temperatures damaging the wire insulation.
P0063 in Ford: Ford usually requires not only replacing the sensor but also correcting poor connections in the electrical wiring.
P0063 in Honda: In Honda models, the P0063 error may be accompanied by decreased power and poor throttle response.
BMW P0063: In BMWs, this can indicate sensor wear combined with other problems with the emissions system.
How do I diagnose error code P0063?
- Connect an OBD2 scanner and read all saved codes.
- Clear the fault codes and check if the error reappears after a test drive.
- Use a multimeter to check the resistance of the oxygen sensor heater (typically between 5 and 14 ohms).
- Check the sensor wiring and connectors for damage or corrosion.
- If everything is normal, check the power supply and grounding of the sensor heating circuit.
Possible Causes and Diagnostic Methods
| Possible Causes | How to Check? |
|---|---|
| Faulty HO2S Sensor | Check heater resistance, replace if necessary |
| Damaged wiring | Inspect cable, test its integrity |
| Connector corrosion | Clean and treat with electric cleaner |
| Short circuit | Wrap the circuit around with a multimeter |
| Electronic control malfunction | Diagnose with a scanner and check for other fault codes |
Required tools: OBD2 scanner, multimeter, electric cleaner, automotive electrical connection diagram, sensor removal tool kit
How to resolve error code P0063? (Solution to the problem)
Simple repair method
- Clean and reconnect the HO2S connector
- Replace damaged wiring or chip
- Reset the error after addressing the cause
In-depth diagnostic and repair solution
- Replace oxygen sensor (Group 2, Sensor 2)
- Inspect and replace heater fuse and relay
- Short circuit test and repair
- Replace or re-flare or replace ECM if necessary.
Troubleshooting Through Symptoms
| Symptoms | Possible Solutions |
|---|---|
| Check if the engine starts | Check and replace the HO2S sensor |
| Increased fuel consumption | Heater circuit diagnostics |
| Decreased acceleration | Check connectors and wiring |
| High emissions | Check catalytic converter operation |
P0063 Frequently Asked Questions
Can I drive with error code P0063?
Undesirable. This error can lead to fuel system malfunction, increased fuel consumption, and damage to the catalytic converter.
What happens if I ignore error P0063?
Ignoring it can lead to environmental degradation, increased emissions, unstable engine operation, and costly emissions system repairs.
Can I replace the oxygen sensor myself?
Yes, you can replace the sensor yourself if you have the necessary qualifications and tools. However, it is very important to take precautions and use genuine parts.
Do I need to re-flash the ECU when I encounter error P0063?
Usually no, but if the error recurs after ruling out all other causes, you may need to check or re-flash the control unit.
How much does it cost to fix a P0063 error?
The cost may range from $20 to $150, depending on whether you only need wiring repair or oxygen sensor replacement.
P0063 Related OBD2 Errors
P0036 – HO2S Heater Control Circuit (Bank 1, Sensor 2)
P0054 – HO2S Heater Resistance (Bank 1, Sensor 2)
P0141 – O2 Sensor Heater Circuit (Bank 1, Sensor 2)
Important! Symptoms may be minor, but ignoring these errors can damage the catalytic converter and other components of the emissions system. Do not delay diagnosing this error—timely correction can prevent catalytic converter damage and ensure stable engine operation.