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Code P2249

Symptoms

• Check Engine Light illuminated

• Poor fuel economy

• Rough engine idle

Common Causes

• Faulty oxygen sensor

• Wiring issues such as short circuits or open circuits

• Faulty PCM

Glossary

PCM: Powertrain Control Module

O2 Sensor: Oxygen Sensor

Related Codes

• P2250

• P0136

Official description

O2 Sensor Reference Voltage Circuit Low Bank 2 Sensor 1

Laymans terms

The car's computer is saying that the oxygen sensor on one side of the engine isn't getting enough power to work properly.

Explanation

The O2 sensor measures the amount of oxygen in the exhaust. This code indicates that the voltage from the sensor is lower than expected.

Technical description

The P2249 code is triggered when the Powertrain Control Module (PCM) detects a low voltage condition in the reference circuit of the oxygen sensor located on Bank 2, Sensor 1. This sensor is responsible for monitoring the oxygen levels in the exhaust gases before the catalytic converter.

Diagnosis steps

• Use an OBD-II scanner to confirm the code.

• Inspect the wiring and connectors for damage.

• Test the oxygen sensor's voltage output.

Repair procedures

• Repair or replace damaged wiring or connectors.

• Replace the faulty oxygen sensor.

• Reprogram or replace the PCM if necessary.

Tools required

• OBD-II scanner

• Multimeter

• Basic hand tools

Estimated repair cost

$150 - $400

Difficulty level

Moderate

Commonly affected vehicles

• Toyota Camry

• Honda Accord

• Ford F-150

Preventive measures

• Regularly inspect and maintain the vehicle's exhaust system.

• Ensure all electrical connections are secure and free of corrosion.

• Use high-quality fuel to prevent sensor contamination.

Error code type

Sensor Issue

User experience recommendations

• Avoid driving long distances until the issue is resolved.

• Have the vehicle inspected by a professional mechanic.

Warranty information

Oxygen sensors may be covered under the vehicle's emissions warranty.

Historical data

This code has been reported in various models, often due to sensor wear or electrical issues.

Urgency level

Moderate – Should be addressed soon to avoid further engine performance issues.

Legal and safety notice

Driving with a faulty oxygen sensor can lead to increased emissions and may not comply with local emissions regulations.

Testing conditions

• Engine at operating temperature

• Vehicle in closed-loop operation

Component location

The oxygen sensor is located in the exhaust manifold on the side of the engine opposite the number one cylinder (Bank 2).

FAQs

Q: Can I drive with a P2249 code?
A: It's not recommended to drive for long periods with this code, as it can lead to poor engine performance and increased emissions.

Q: How do I know if my oxygen sensor is bad?
A: Symptoms include a rough idle, poor fuel economy, and the Check Engine Light being on.

Last updated: Mar 2, 2026 • Source: internal database
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