P2203 Fault Code

NOx Sensor Circuit High Bank 1

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

The P2203 fault code indicates a problem with the NOx (Nitrogen Oxide) sensor circuit for Bank 1. This sensor is responsible for monitoring the amount of nitrogen oxides produced by the engine and sends this information to the engine control module (ECM) for optimal performance and emissions control. A high reading in this circuit can lead to reduced fuel efficiency and increased emissions, as the engine may struggle to meet regulatory standards.

What are the symptoms of the P2203 code?

Symptoms of the P2203 code may include:

• Check Engine Light illuminated
• Increased nitrogen oxide emissions
• Decreased fuel economy
• Rough idling or poor engine performance
• Failure to pass emissions inspection

What causes the P2203 code?

Common causes of the P2203 fault code include:

• Faulty NOx sensor
• Open or shorted wires in the NOx sensor circuit
• Poor connections or corroded terminals in the sensor circuit
• Issues with the exhaust system, leading to incorrect readings
• Malfunctioning engine control module (ECM)

How to fix P2203?

To resolve the P2203 fault code, follow these steps:

• Inspect the NOx sensor and its wiring for any visible damage or corrosion.
• Use a multimeter to test the sensor’s voltage and ground signals.
• Replace the NOx sensor if it is faulty.
• Repair any damaged wiring or connectors in the circuit.
• Clear the fault codes and conduct a test drive to confirm the issue has been resolved.