AutoCodes – Scion – P0139 2007 Scion xB

P0139 2007 Scion xB Code - Oxygen Sensor Circuit Slow Response Bank 1 Sensor 2

Quick Answer

The rear Heated Oxygen (HO2) sensor (bank 1 sensor 2) is located behind the Three-Way Catalytic Converter (TWC) and detects the oxygen concentration in the exhaust gas. 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 2007 Scion xB indicates Oxygen Sensor Circuit Slow Response Bank 1 Sensor 2.
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 2,607

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 14, 2021

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0139 2007 Scion xB Description

The rear Heated Oxygen (HO2) sensor (bank 1 sensor 2) is located behind the Three-Way Catalytic Converter (TWC) and detects the oxygen concentration in the exhaust gas. For optimum TWC operation, the air-fuel mixture must be maintained as close as possible to the stoichiometric ratio. The HO2 sensor output voltage changes dramatically in the vicinity of the stoichiometric ratio. By making adjustments in accordance with these signal voltage changes, the ECM adjusts the fuel injection time so that the air-fuel ratio remains as close as possible to stoichiometric levels. The rear HO2 sensor generates a voltage that ranges from 0.1 V to 0.9 V according to the oxygen concentration in the exhaust gas. When the oxygen concentration in the exhaust gas increases, the HO2 sensor voltage drops below 0.45 V. The ECM interprets this as the air-fuel ratio is lean. Alternatively, the sensor voltage rises to more than 0.45 V when there is no oxygen in the exhaust gas. The ECM interprets this as the air-fuel ratio is rich.

OBDII Code P0139 2007 Scion xB - Oxygen Sensor Circuit Slow Response Bank 1 Sensor 2 - AutoCodes.com — P0139 2007 Scion xB Code - Oxygen Sensor Circuit Slow Response Bank 1 Sensor 2

What does this mean?

What are the Possible Causes of the DTC P0139 2007 Scion xB?

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 2007 Scion xB?

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 2007 Scion xB 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 2007 Scion xB Code

1. What are the common symptoms of OBDII code P0139 in a 2007 Scion xB?

- Common symptoms include decreased fuel efficiency, rough idling, and potential stalling of the vehicle.

2. What does the OBDII code P0139 indicate in a 2007 Scion xB?

- This code indicates a slow response from the oxygen sensor located in Bank 1 Sensor 2 of the vehicle's exhaust system.

3. What are the possible causes of the Oxygen Sensor Circuit Slow Response Bank 1 Sensor 2 code in a 2007 Scion xB?

- Potential causes include a faulty oxygen sensor, wiring issues, exhaust leaks, or a problem with the vehicle's engine control module (ECM).

4. How can I diagnose the cause of OBDII code P0139 in my 2007 Scion xB?

- Diagnosing this code may involve checking the oxygen sensor's wiring, inspecting for exhaust leaks, and testing the sensor's response using a scan tool.

5. Can I drive my 2007 Scion xB with the P0139 code?

- It is generally not recommended to drive the vehicle with this code, as it can lead to decreased performance and potential damage to the catalytic converter.

6. How can I repair the Oxygen Sensor Circuit Slow Response Bank 1 Sensor 2 issue in my 2007 Scion xB?

- Repair options may include replacing the oxygen sensor, repairing any damaged wiring, fixing exhaust leaks, or reprogramming the ECM.

7. How much does it typically cost to fix the P0139 code in a 2007 Scion xB?

- The cost of fixing this code can vary depending on the specific issue, but it may range from $100 to $400 for parts and labor.

8. Can I reset the OBDII code P0139 in my 2007 Scion xB with a scan tool?

- Yes, you can reset the code with a scan tool, but it is important to address the underlying issue causing the code before resetting it.

9. How often does the oxygen sensor in a 2007 Scion xB typically need to be replaced?

- Oxygen sensors generally have a lifespan of 60,000 to 100,000 miles, so it may need to be replaced within that mileage range.

10. Is it possible for a DIY enthusiast to fix the P0139 code in a 2007 Scion xB?

- Depending on the individual's level of expertise, DIY enthusiasts may be able to address simple causes like wiring issues, but more complex problems may require professional assistance.