AutoCodes – KIA – P0139 KIA

P0139 KIA Code - HO2S12 Circuit 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 KIA indicates HO2S12 Circuit 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 21,017

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 KIA 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 KIA - HO2S12 Circuit Slow Response - AutoCodes.com — P0139 KIA Code - HO2S12 Circuit Slow Response

What does this mean?

What are the Possible Causes of the DTC P0139 KIA?

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 KIA?

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 KIA 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 KIA Code

1. What are the common symptoms of OBDII code P0139 in a KIA vehicle?

- Common symptoms of code P0139 in a KIA include poor fuel economy, rough idle, engine hesitation, and the illumination of the check engine light.

2. What does the OBDII code P0139 in a KIA mean?

- OBDII code P0139 for a KIA indicates that the HO2S12 (Heated Oxygen Sensor Bank 1 Sensor 2) circuit is experiencing a slow response.

3. What are the possible causes of OBDII code P0139 in a KIA?

- The potential causes of code P0139 in a KIA include a faulty HO2S12 sensor, wiring issues in the sensor circuit, exhaust leaks, or a problem with the vehicle's engine control module (ECM).

4. How can I diagnose the OBDII code P0139 in my KIA?

- To diagnose code P0139 in a KIA, you can use an OBDII scanner to read the code and monitor the sensor's response time. Additionally, inspect the sensor wiring and check for any exhaust leaks.

5. Can I drive my KIA with the OBDII code P0139?

- It is not recommended to drive your KIA with an unresolved P0139 code, as it can lead to poor engine performance and potential damage to the catalytic converter over time.

6. How can I repair the OBDII code P0139 in my KIA?

- Repairing code P0139 in a KIA typically involves replacing the HO2S12 sensor if it is faulty, repairing any damaged wiring, fixing exhaust leaks, or addressing any issues with the engine control module.

7. Is it necessary to reset the OBDII code P0139 in my KIA after repairs?

- Yes, it is important to reset the OBDII code P0139 in your KIA after completing repairs to see if the issue has been resolved. This can be done using an OBDII scanner.

8. How much does it cost to fix the OBDII code P0139 in a KIA at a mechanic?

- The cost of fixing code P0139 in a KIA at a mechanic can vary depending on the exact cause of the issue, but it may range from $100 to $300 for parts and labor.

9. Can a DIY enthusiast repair the OBDII code P0139 in a KIA?

- Yes, a DIY enthusiast with the necessary tools and knowledge can attempt to repair code P0139 in a KIA by following repair guides and procedures for sensor replacement, wiring checks, and other related tasks.

10. How long does it take to repair the OBDII code P0139 in a KIA?

- The time required to repair code P0139 in a KIA can vary based on the specific cause of the issue and the skill level of the person performing the repairs. Generally, it may take anywhere from 1 to 3 hours to complete the repair.