AutoCodes – Nissan – P0139 2010 Nissan Pathfinder

P0139 2010 Nissan Pathfinder 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 Pathfinder 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 2,139

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 Mar 25, 2024

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

What does this mean?

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

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 Pathfinder?

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 Pathfinder 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 Pathfinder Code

1. What are the common symptoms of OBDII code P0139 on a 2010 Nissan Pathfinder?

- Common symptoms include poor fuel economy, rough idling, and a Check Engine light illuminated on the dashboard.

2. What does the OBDII code P0139 "HO2S12 Slow Response" mean for a 2010 Nissan Pathfinder?

- This code indicates that the downstream oxygen sensor (sensor 2 in bank 1) is responding slowly to changes in the exhaust oxygen content.

3. What are the possible causes of OBDII code P0139 on a 2010 Nissan Pathfinder?

- Potential causes include a faulty oxygen sensor, wiring issues, exhaust leaks, engine misfires, or a malfunctioning catalytic converter.

4. How can I diagnose the root cause of OBDII code P0139 on my 2010 Nissan Pathfinder?

- Diagnosing this code typically involves checking the oxygen sensor's wiring, inspecting for exhaust leaks, testing the sensor's response, and verifying proper engine operation.

5. Can I continue driving my 2010 Nissan Pathfinder with OBDII code P0139?

- It is generally not recommended to continue driving with this code as it can lead to decreased fuel efficiency and potential damage to the catalytic converter over time.

6. How can I repair OBDII code P0139 on a 2010 Nissan Pathfinder?

- Repair options may include replacing the downstream oxygen sensor, repairing wiring issues, fixing exhaust leaks, addressing engine misfires, or replacing a faulty catalytic converter.

7. Is it possible to reset the Check Engine light after repairing OBDII code P0139 on a 2010 Nissan Pathfinder?

- Yes, the Check Engine light can be reset using an OBDII scanner or by disconnecting the car's battery for a few minutes. However, it's important to ensure that the underlying issue has been resolved first.

8. How much does it typically cost to repair OBDII code P0139 on a 2010 Nissan Pathfinder?

- The cost of repairs can vary depending on the exact cause of the code, but it may range from $100 to $500 or more, including parts and labor.

9. Can a DIY enthusiast fix OBDII code P0139 on a 2010 Nissan Pathfinder?

- Depending on the root cause, some DIY enthusiasts with the necessary tools and knowledge may be able to address this code themselves, particularly if it involves simple tasks like replacing the oxygen sensor.

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

- While the frequency can vary, P0139 is a relatively common OBDII code seen in vehicles with oxygen sensor or exhaust system issues, including the 2010 Nissan Pathfinder.