AutoCodes – GMC – P0131 GMC

P0131 GMC Code - HO2S Circuit Low Voltage Bank 1 Sensor 1

Quick Answer

The Heated Oxygen Sensors (HO2S) are used for fuel control and catalyst monitoring. Common causes include Faulty Front Heated Oxygen Sensor (HO2S) Bank 1, Front Heated Oxygen Sensor Bank 1 harness is open or shorted, Front Heated 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: P0131 GMC indicates HO2S Circuit Low Voltage Bank 1 Sensor 1.
Common causes: Common causes include Faulty Front Heated Oxygen Sensor (HO2S) Bank 1, Front Heated Oxygen Sensor Bank 1 harness is open or shorted, Front Heated 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 16,011

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 26, 2022

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0131 GMC 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 detects that the heated oxygen sensor is shorted to ground if the HO2S voltage is less than 50 mV.

OBDII Code P0131 GMC - HO2S Circuit Low Voltage Bank 1 Sensor 1 - AutoCodes.com — P0131 GMC Code - HO2S Circuit Low Voltage Bank 1 Sensor 1

What does this mean?

What are the Possible Causes of the DTC P0131 GMC?

Faulty Front Heated Oxygen Sensor (HO2S) Bank 1
Front Heated Oxygen Sensor Bank 1 harness is open or shorted
Front Heated Oxygen Sensor Bank 1 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 P0131 GMC?

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 Front Heated Oxygen Sensor (HO2S) Bank 1 usually takes care of the problem.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0131 GMC 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.

Need more information about the P0131 GMC code?

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Information for Specific GMC Models

P0131 2014 GMC Sierra — HO2S Circuit Low Voltage Bank 1 Sensor 1
P0131 2015 GMC Sierra — HO2S Circuit Low Voltage Bank 1 Sensor 1
P0131 2016 GMC Sierra — HO2S Circuit Low Voltage Bank 1 Sensor 1
P0131 2017 GMC Sierra — HO2S Circuit Low Voltage Bank 1 Sensor 1
P0131 2018 GMC Sierra — HO2S Circuit Low Voltage Bank 1 Sensor 1

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 P0131 GMC Code

1. What are common symptoms of OBDII code P0131 GMC (HO2S Circuit Low Voltage Bank 1 Sensor 1)?

- Common symptoms include poor fuel economy, rough idling, engine hesitation, and an illuminated check engine light.

2. What causes the OBDII code P0131 GMC to trigger?

- The code P0131 is triggered when the oxygen sensor (O2 sensor) in Bank 1 Sensor 1 detects a low voltage condition.

3. How serious is the OBDII code P0131 GMC?

- While the vehicle may still be operable with this code, it can lead to decreased fuel efficiency and potential damage to the catalytic converter if left unresolved.

4. How can I diagnose the OBDII code P0131 GMC?

- Diagnosing this code typically involves checking the oxygen sensor's wiring, connectors, and sensor itself for any faults or damage.

5. Can I drive my vehicle with the OBDII code P0131 GMC?

- It is generally not recommended to drive the vehicle for an extended period with this code, as it can lead to further issues if left unresolved.

6. How can I repair the OBDII code P0131 GMC?

- Repairing this code often involves replacing the Bank 1 Sensor 1 oxygen sensor, ensuring proper wiring connections, and clearing the code from the vehicle's system.

7. Are there any DIY tips for fixing the OBDII code P0131 GMC?

- While some may attempt to replace the oxygen sensor themselves, it is recommended to have a professional mechanic diagnose and repair the issue to ensure it is resolved correctly.

8. What is the cost to fix the OBDII code P0131 GMC?

- The cost to fix this code can vary depending on the vehicle make and model, but it typically involves the cost of a new oxygen sensor and labor for installation.

9. How long does it take to repair the OBDII code P0131 GMC?

- The repair time for this code can vary but typically takes anywhere from 1-2 hours to diagnose, replace the sensor, and clear the code from the vehicle's system.

10. Can the OBDII code P0131 GMC recur after repair?

- If the underlying issue causing the code is not properly addressed, there is a possibility that the code may recur. It is essential to ensure all components are functioning correctly to prevent this.