P2237 Fault Code

O2 Sensor Positive Current Control Circuit/Open Bank 1 Sensor 1

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

The P2237 code indicates an issue with the O2 sensor positive current control circuit for the first sensor in Bank 1. This sensor plays a crucial role in monitoring exhaust emissions and helps the engine control module (ECM) adjust the air-fuel mixture for optimal performance. The positive current control circuit is responsible for providing the necessary voltage to the O2 sensor, and an open circuit or fault can lead to incorrect readings.

• The sensor is usually located in the exhaust manifold or just after it.
• A malfunction can lead to increased emissions and decreased fuel efficiency.

What are the symptoms of the P2237 code?

Symptoms associated with a P2237 error may include:

• Check Engine Light (CEL) illuminated.
• Poor fuel economy due to incorrect fuel mixture.
• Increased emissions potentially causing failure in emissions tests.
• Rough engine idle or stalling in severe cases.
• Potential triggering of additional diagnostic trouble codes (DTCs).

What causes the P2237 code?

The primary causes of a P2237 fault code include:

• Faulty O2 sensor.
• Damaged wiring or connectors in the positive current control circuit.
• Corrosion or poor connections in the electrical connectors.
• A blown fuse that supplies power to the O2 sensor.
• Issues with the ECM or its programming.

How to fix P2237?

To resolve a P2237 fault code, consider the following steps:

• Inspect the O2 sensor for visible damage and replace if necessary.
• Check the wiring and connectors in the positive current control circuit for any signs of damage, corrosion, or loose connections.
• Test the O2 sensor circuit with a multimeter to determine if it is sending and receiving the correct voltage signals.
• Replace any blown fuses connected to the sensor circuit.
• If the issue persists, a reprogramming of the ECM may be required after ensuring all hardware is functioning properly.