AutoCodes – Buick – P2272 Buick

P2272 Buick Code - HO2S Signal Stuck Lean Bank 2 Sensor 2

Quick Answer

The Heated Oxygen Sensors (HO2S) are used for fuel control and catalyst monitoring. Common causes include Faulty Heated Oxygen Bank 2 Sensor 2, Heated Oxygen Bank 2 Sensor 2 harness is open or shorted, Heated Oxygen Bank 2 Sensor 2 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: P2272 Buick indicates HO2S Signal Stuck Lean Bank 2 Sensor 2.
Common causes: Common causes include Faulty Heated Oxygen Bank 2 Sensor 2, Heated Oxygen Bank 2 Sensor 2 harness is open or shorted, Heated Oxygen Bank 2 Sensor 2 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 419

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 May 28, 2022

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P2272 Buick Description

The Heated Oxygen Sensors (HO2S) are used for fuel control and catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the Engine Control Module (ECM) operates in an Open Loop mode, ignoring the HO2S signal voltage while calculating the air-to-fuel ratio. While the engine runs, the HO2S heats up and begins to generate a voltage within a range of 0 - 1, 000 mV. Once sufficient HO2S voltage fluctuation is observed by the ECM, Closed Loop is entered. The ECM uses the HO2S voltage to determine the air-to-fuel ratio. An HO2S voltage that increases toward 1, 000 mV indicates a rich fuel mixture. An HO2S voltage that decreases toward 0 mV indicates a lean fuel mixture.
The heating elements inside each HO2S heat the sensor to bring the sensor up to operating conditions faster. This allows the system to enter Closed Loop earlier and the ECM to calculate the air-to-fuel ratio sooner.
The Diagnostic Trouble Code (DTC) will be set when the ECM does not detect an HO2S voltage greater than 800 mV before accumulated mass airflow exceeds a calibrated value.

OBDII Code P2272 Buick - HO2S Signal Stuck Lean Bank 2 Sensor 2 - AutoCodes.com — P2272 Buick Code - HO2S Signal Stuck Lean Bank 2 Sensor 2

What does this mean?

What are the Possible Causes of the DTC P2272 Buick?

Faulty Heated Oxygen Bank 2 Sensor 2
Heated Oxygen Bank 2 Sensor 2 harness is open or shorted
Heated Oxygen Bank 2 Sensor 2 circuit poor electrical connection
Low or high fuel system pressure
Fuel contamination
Faulty fuel injectors
Exhaust gas leaks
Engine vacuum leaks

How to Fix the DTC P2272 Buick?

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 does this mean?

Code Tech Notes

Replacing the Rear Heated Oxygen Sensors (HO2S) usually takes care of the problem.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P2272 Buick 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 P2272 Buick Code

What does the OBDII code P2272 mean for a Buick?

Code P2272 indicates that the oxygen sensor (HO2S) located on Bank 2, Sensor 2, is detecting a consistently lean air-fuel mixture, meaning there is too much air and not enough fuel.

What are the common symptoms of a P2272 code on a Buick?

Symptoms may include a check engine light, reduced fuel efficiency, poor engine performance, rough idling, and possible difficulty passing emissions tests.

What causes the P2272 code to appear on a Buick?

Common causes include a faulty downstream oxygen sensor, exhaust leaks near the sensor, a damaged wiring harness, or issues with the engine running lean due to fuel delivery problems.

Can I drive my Buick with a P2272 code?

While it may be possible to drive the vehicle, it is not recommended as it could lead to reduced fuel efficiency, poor performance, and potential damage to the catalytic converter if left unresolved.

How do I diagnose the P2272 code on a Buick?

Start by using an OBDII scanner to confirm the code. Then inspect the downstream oxygen sensor, check for exhaust leaks, examine the wiring and connectors, and test the fuel system for lean conditions.

How do I fix a P2272 code on a Buick?

Repairs may include replacing the faulty oxygen sensor, fixing exhaust leaks, repairing or replacing damaged wiring, or addressing fuel system issues causing a lean air-fuel mixture.

How much does it cost to repair the P2272 code on a Buick?

The repair cost can vary, but replacing an oxygen sensor typically ranges from $150 to $300, while fixing exhaust leaks or addressing fuel system issues may cost more depending on the complexity.

Can a dirty or malfunctioning mass airflow (MAF) sensor cause a P2272 code?

Yes, a dirty or faulty MAF sensor can contribute to a lean condition, which may trigger the P2272 code in some cases.

Is it necessary to replace the catalytic converter for a P2272 code?

Not usually. This code typically points to an issue with the oxygen sensor or air-fuel mixture, but if the problem is ignored for too long, it could damage the catalytic converter.

How can I prevent the P2272 code from recurring on my Buick?

Regular maintenance, including inspecting sensors, cleaning the MAF sensor, checking for exhaust leaks, and ensuring proper fuel system operation, can help prevent this code from returning.