AutoCodes – Hyundai – P2251 Hyundai

P2251 Hyundai Code - O2 Sensor Negative Current Control Circuit Open Bank 1 Sensor 1

Quick Answer

The Front Oxygen Sensor (O2 Sensor 1) is placed into the exhaust manifold. Common causes include Faulty Front Oxygen Sensor Bank 1, Front Oxygen Sensor Bank 1 harness is open or shorted, Front Oxygen Sensor Bank 1 circuit poor electrical connection. Severity is Moderate - service should be scheduled soon. The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.

What it means: P2251 Hyundai indicates O2 Sensor Negative Current Control Circuit Open Bank 1 Sensor 1.
Common causes: Common causes include Faulty Front Oxygen Sensor Bank 1, Front Oxygen Sensor Bank 1 harness is open or shorted, Front Oxygen Sensor Bank 1 circuit poor electrical connection.
Severity: Moderate - service should be scheduled soon.
Can I drive?: The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.

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Code Popularity 27,995

How popular is this code, among other codes? Low

Repair Importance Level

Moderate (Service soon) (2 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jun 14, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P2251 Hyundai Description

The Front Oxygen Sensor (O2 Sensor 1) is placed into the exhaust manifold. It detects the amount of oxygen in the exhaust gas compared to the outside air. The heated oxygen sensor 1 has a closed-end tube made of ceramic zirconia. The zirconia generates voltage from approximately 1V in richer conditions to 0V in leaner conditions. The heated oxygen sensor 1 signal is sent to the Engine Control Module (ECM). The ECM adjusts the injection pulse duration to achieve the ideal air-fuel ratio. The ideal air-fuel ratio occurs near the radical change from 1V to 0V.

OBDII Code P2251 Hyundai - O2 Sensor Negative Current Control Circuit Open Bank 1 Sensor 1 - AutoCodes.com — P2251 Hyundai Code - O2 Sensor Negative Current Control Circuit Open Bank 1 Sensor 1

What does this mean?

What are the Possible Causes of the DTC P2251 Hyundai?

Faulty Front Oxygen Sensor Bank 1
Front Oxygen Sensor Bank 1 harness is open or shorted
Front Oxygen Sensor Bank 1 circuit poor electrical connection

How to Fix the DTC P2251 Hyundai?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P2251 Hyundai code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P2251 Hyundai Code

1. What does the OBDII code P2251 mean for a Hyundai?

P2251 indicates an issue with the O2 Sensor Negative Current Control Circuit Open for Bank 1 Sensor 1, meaning the sensor is not properly communicating with the engine control module (ECM).

2. What are the common symptoms of code P2251 in a Hyundai?

Symptoms may include the check engine light turning on, poor fuel efficiency, rough idling, reduced engine performance, and increased emissions.

3. What causes the P2251 code to appear in a Hyundai?

Possible causes include a damaged or disconnected oxygen sensor, corroded or broken wiring, a faulty ECM, or an open circuit in the O2 sensor circuit.

4. Which oxygen sensor does P2251 refer to in a Hyundai?

P2251 refers to the oxygen sensor in Bank 1 Sensor 1, which is the upstream sensor located before the catalytic converter on the side of the engine with cylinder 1.

5. Can driving with code P2251 cause damage to my Hyundai?

While it may not cause immediate damage, prolonged driving with this issue can lead to poor engine performance, increased fuel consumption, and potential damage to the catalytic converter.

6. How do you diagnose the P2251 code in a Hyundai?

Diagnosis involves using an OBDII scanner to confirm the code, inspecting the O2 sensor wiring for damage or corrosion, testing the sensor itself, and checking the ECM for faults.

7. How do you fix the OBDII code P2251 in a Hyundai?

Common fixes include repairing or replacing damaged wiring, replacing the faulty oxygen sensor, or in rare cases, addressing ECM issues if the circuit is functioning properly.

8. How much does it cost to repair the P2251 code in a Hyundai?

The cost to repair P2251 varies but typically includes $150â€“$300 for an oxygen sensor replacement, plus any additional costs for wiring repairs or diagnostic labor.

9. Can a loose connection cause the P2251 code in a Hyundai?

Yes, a loose or corroded connection in the oxygen sensor wiring or connectors can cause the circuit to open and trigger the P2251 code.

10. How can I prevent the P2251 code from reoccurring in my Hyundai?

Regular maintenance, such as inspecting and cleaning wiring connections, ensuring proper installation of the oxygen sensor, and addressing issues promptly, can help prevent this code from reappearing.