P0163 Fault Code

O2 Sensor Circuit Low Voltage (Bank 2 Sensor 3)

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

The P0163 code indicates that there is a low voltage issue in the O2 sensor circuit for Bank 2 Sensor 3. This sensor is crucial for monitoring the level of oxygen in the exhaust gases, helping the engine control unit (ECU) adjust the air-fuel mixture for optimal performance and emissions control.

• Understanding the function of the oxygen sensor can help diagnose issues related to fuel economy and exhaust emissions.
• A low voltage reading may mean the sensor is malfunctioning, or there could be issues with wiring or connectors leading to the sensor.

What are the symptoms of the P0163 code?

When the P0163 code is triggered, you may notice:

• Decreased fuel efficiency, as the engine may be running too rich or too lean.
• Rough engine idle or hesitation during acceleration due to improper air-fuel mixture.
• Increased exhaust emissions, possibly leading to failed emissions tests.
• Check Engine Light (CEL) illuminated on the dashboard to indicate a fault in the O2 sensor circuit.

What causes the P0163 code?

Several factors can trigger the P0163 code:

• A faulty O2 sensor that is failing to operate correctly.
• Damaged wiring or connectors in the sensor circuit, leading to low voltage readings.
• A short circuit or open circuit in the wiring harness.
• Issues with the engine control unit (ECU) not processing signals correctly.
• Poor ground connections affecting the sensor's performance.

How to fix P0163?

To address the P0163 code, the following steps can be taken:

• Inspect the O2 sensor for physical damage and replace it if necessary.
• Check the wiring and connectors leading to Bank 2 Sensor 3 for any signs of wear, corrosion, or disconnection, repairing or replacing as needed.
• Test the voltage readings at the sensor to confirm whether it is within the manufacturer's specifications. If not, further investigation of the ECU and ground connections may be required.
• Clear the fault code and conduct a test drive to ensure the repairs have resolved the issue.