AutoCodes – Nissan – P0139 2010 Nissan Sentra

P0139 2010 Nissan Sentra Code - HO2S12 Slow Response

Quick Answer

The Heated Oxygen Sensor 2 (HO2S), after three way catalyst (manifold), monitors the oxygen level in the exhaust gas on each bank. Common causes include Faulty Rear Heated Oxygen Sensor Bank 1, Rear Heated Oxygen Sensor Bank 1 harness is open or shorted, Rear 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: P0139 2010 Nissan Sentra indicates HO2S12 Slow Response.
Common causes: Common causes include Faulty Rear Heated Oxygen Sensor Bank 1, Rear Heated Oxygen Sensor Bank 1 harness is open or shorted, Rear 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 2,685

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 Apr 12, 2019

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0139 2010 Nissan Sentra Description

The Heated Oxygen Sensor 2 (HO2S), after three way catalyst (manifold), monitors the oxygen level in the exhaust gas on each bank. For optimum catalyst operation, the air fuel mixture (air-fuel ratio) must be maintained near the ideal stoichiometric ratio. The HO2S output voltage changes suddenly in the vicinity of the stoichiometric ratio. The Engine Control Module (ECM) adjusts the fuel injection time so that the air-fuel ratio is nearly stoichiometric. The HO2S generates a voltage between 0.1 and 0.9 V in response to oxygen in the exhaust gas. If the oxygen in the exhaust gas increases, the air-fuel ratio becomes Lean. The ECM interprets Lean when the HO2S voltage is below 0.45 V. If the oxygen in the exhaust gas decreases, the air-fuel ratio becomes Rich. The ECM interprets Rich when the HO2S voltage is above 0.45 V.

OBDII Code P0139 2010 Nissan Sentra - HO2S12 Slow Response - AutoCodes.com — P0139 2010 Nissan Sentra Code - HO2S12 Slow Response

What does this mean?

What are the Possible Causes of the DTC P0139 2010 Nissan Sentra?

Faulty Rear Heated Oxygen Sensor Bank 1
Rear Heated Oxygen Sensor Bank 1 harness is open or shorted
Rear Heated Oxygen Sensor Bank 1 circuit poor electrical connection
Inappropriate fuel pressure
Faulty fuel injectors
Intake air leaks may be faulty
Exhaust gas leaks

How to Fix the DTC P0139 2010 Nissan Sentra?

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 Sensor Bank 1 usually takes care of the problem.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0139 2010 Nissan Sentra 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 P0139 2010 Nissan Sentra Code

1. What is OBDII code P0139 in a 2010 Nissan Sentra?

OBDII code P0139 in a 2010 Nissan Sentra indicates a slow response from the HO2S12 sensor, also known as the downstream oxygen sensor.

2. What are the common symptoms of OBDII code P0139 in a 2010 Nissan Sentra?

Common symptoms of OBDII code P0139 in a 2010 Nissan Sentra include poor fuel economy, rough idling, hesitation during acceleration, and an illuminated check engine light.

3. What are the possible causes of OBDII code P0139 in a 2010 Nissan Sentra?

Possible causes of OBDII code P0139 in a 2010 Nissan Sentra include a faulty HO2S12 sensor, wiring issues, exhaust leaks, or a problem with the engine's air-fuel mixture.

4. How can I diagnose OBDII code P0139 in a 2010 Nissan Sentra?

Diagnosing OBDII code P0139 in a 2010 Nissan Sentra involves using an OBDII scanner to retrieve the code, inspecting the HO2S12 sensor and its wiring, checking for exhaust leaks, and verifying the engine's air-fuel mixture.

5. Can I drive my 2010 Nissan Sentra with OBDII code P0139?

It is generally not recommended to drive your 2010 Nissan Sentra with OBDII code P0139, as it can lead to poor fuel efficiency and potential damage to the catalytic converter over time.

6. How can I repair OBDII code P0139 in a 2010 Nissan Sentra?

Repairing OBDII code P0139 in a 2010 Nissan Sentra involves replacing the HO2S12 sensor if faulty, repairing any damaged wiring, fixing exhaust leaks, and addressing any issues with the engine's air-fuel mixture.

7. Is it possible to reset OBDII code P0139 in a 2010 Nissan Sentra without fixing the underlying issue?

Resetting OBDII code P0139 in a 2010 Nissan Sentra without fixing the underlying issue will only temporarily turn off the check engine light, as the code will reappear once the system detects the same problem again.

8. How much does it cost to fix OBDII code P0139 in a 2010 Nissan Sentra?

The cost to fix OBDII code P0139 in a 2010 Nissan Sentra can vary depending on the specific issue causing the code, but it may range from $100 to $300 or more, including parts and labor.

9. Can a DIY enthusiast repair OBDII code P0139 in a 2010 Nissan Sentra?

A DIY enthusiast with automotive repair experience may be able to repair OBDII code P0139 in a 2010 Nissan Sentra by following the proper diagnostic procedures and replacing the faulty components themselves.

10. How often does OBDII code P0139 occur in a 2010 Nissan Sentra?

OBDII code P0139 in a 2010 Nissan Sentra can occur due to various factors, such as sensor degradation or wiring issues, so it is not uncommon for this code to appear sporadically during the vehicle's lifetime.