P0064 Fault Code

HO2S Heater Control Circuit High (Bank 2 Sensor 3)

• What does that mean?
• Symptoms
• Causes
• Solutions

The P0064 fault code indicates a problem with the HO2S (Heated Oxygen Sensor) heater control circuit on bank 2 sensor 3 of the vehicle. This code specifically refers to the third oxygen sensor located on bank 2 of the engine.

The purpose of the HO2S heater circuit is to quickly bring the sensor up to operating temperature for optimal performance. This helps in providing accurate and reliable oxygen sensor readings to the engine control module (ECM) or powertrain control module (PCM).

When the ECM detects that the HO2S heater control circuit on bank 2 sensor 3 is operating at a high voltage level for an extended period of time, it triggers the P0064 code and activates the Check Engine Light.

Some of the common causes of this fault code include a faulty oxygen sensor, a damaged or shorted wiring harness, or a malfunctioning ECM/PCM. Additional factors like corroded connectors, blown fuses, or faulty relay can also contribute to this issue.

To diagnose and resolve this problem, it is recommended to follow these steps:

1. Perform a visual inspection: Check for any obvious signs of damaged wires, loose connections, or corrosion on the sensor and its wiring harness.

2. Test the sensor: Use a multimeter to test the resistance of the oxygen sensor. If it falls outside the specified range, the sensor may need to be replaced.

3. Check the wiring: Inspect the wiring harness for any signs of damage, such as frayed wires or shorts. Repair or replace the wiring as necessary.

4. Test the heater circuit: Use a multimeter to check the voltage and resistance in the heater circuit. Compare the readings to the manufacturer's specifications.

5. Test the ECM/PCM: If all other components check out fine, it may be necessary to perform further diagnostics on the ECM/PCM to determine if it is functioning correctly.

Once the underlying issue has been identified and resolved, the fault code can be cleared using an OBD-II scanner. If the problem persists after repairs, it is recommended to seek assistance from a qualified mechanic or dealership for further diagnosis and repair.

What are the symptoms of the P0064 code?

The P0064 fault code refers to the HO2S (Heated Oxygen Sensor) Heater Control Circuit High on Bank 2 Sensor 3. This fault code is typically found in vehicles with multiple oxygen sensors, and it indicates that there is an issue with the heater control circuit on the third oxygen sensor of the second bank.

Symptoms of the P0064 fault code may include:

1. Check Engine Light (CEL) or Malfunction Indicator Lamp (MIL) illuminated on the dashboard.
2. Poor engine performance or rough idle.
3. Decreased fuel efficiency.
4. Failed emission test.
5. Possible sulfur or rotten egg smell from the exhaust.

If you are experiencing any of these symptoms, it is recommended to have your vehicle diagnosed and repaired by a qualified technician.

What causes the P0064 code?

P0064 is a fault code that indicates a high HO2S (Heated Oxygen Sensor) heater control circuit signal on Bank 2 Sensor 3. This fault code usually indicates a problem with the heater circuit of the third oxygen sensor on bank 2 of the engine. The potential causes of this fault code include:

1. Faulty oxygen sensor: The oxygen sensor may be defective and not functioning properly, causing the heater control circuit signal to be high.
2. Open or short in the wiring: There could be an open or a short circuit in the wiring harness connecting the oxygen sensor to the engine control module (ECM).
3. Sensor heater relay: The relay that controls the heater circuit for the oxygen sensor may be faulty or not functioning correctly.
4. ECM malfunction: There could be an issue with the ECM itself, causing it to send a high signal to the oxygen sensor heater circuit.

To diagnose and repair this fault code, it is recommended to follow these steps:

1. Check the wiring: Inspect the wiring harness for any signs of damage, such as frayed wires or loose connections. Repair or replace any damaged wiring as necessary.
2. Test the oxygen sensor: Use a multimeter to test the oxygen sensor for proper resistance values. If the sensor is found to be faulty, replace it with a new one.
3. Check the sensor heater relay: Test the relay using a multimeter to ensure it is functioning correctly. If the relay is faulty, replace it.
4. Test the ECM: If all other components check out, it may be necessary to test the ECM using specialized diagnostic tools. If a malfunction is detected, the ECM may need to be repaired or replaced.

It is recommended to consult the vehicle's service manual or seek assistance from a qualified mechanic for accurate diagnosis and repair of the P0064 fault code.

How to fix P0064?

To fix the P0064 fault code, which indicates a high HO2S (Heated Oxygen Sensor) Heater Control Circuit for Bank 2 Sensor 3, you can follow these steps:

1. Check the wiring: Inspect the wiring harness and connector for any signs of damage or loose connections. Repair or replace any damaged or faulty wiring.

2. Test the heater circuit: Use a multimeter to check the resistance of the heater circuit in the Bank 2 Sensor 3 HO2S. It should typically be around 5-20 ohms. If the resistance is outside of this range, replace the sensor.

3. Replace the sensor: If the sensor fails the resistance test or shows any other signs of malfunction, it's recommended to replace the Bank 2 Sensor 3 HO2S with a new one.

4. Clear the fault code: After repairing or replacing the sensor, clear the fault code using an OBD-II scanner or by disconnecting the battery for a few minutes. This will reset the vehicle's computer and clear the stored fault code.

5. Test the system: After performing the above steps, test the vehicle to ensure the fault code does not reappear. Take the car for a test drive and monitor the sensor's readings to confirm that it is functioning properly.

It's important to note that if you are not comfortable performing these steps yourself, it is recommended to seek professional assistance from a certified mechanic or automotive technician.