AutoCodes – Ford – P0139 2006 Ford Fusion

P0139 2006 Ford Fusion Code - O2 Sensor Circuit Slow Response Bank 1 Sensor 2

Quick Answer

The heated oxygen sensor (HO2S) monitor tracks the rate of voltage change during the rise and fall of the HO2S signal. 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 2006 Ford Fusion indicates O2 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 2,422

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 Jun 14, 2020

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0139 2006 Ford Fusion Description

The heated oxygen sensor (HO2S) monitor tracks the rate of voltage change during the rise and fall of the HO2S signal. When the rate of voltage change is less than a calibrated value, the Powertrain Control Module (PCM) begins to modify the fuel trim attempting to increase the HO2S voltage switch rate. The DTC sets when the PCM is at the allowable limit or has exceeded an allowable length of time for fuel trim modification, without detecting an acceptable rate of voltage change.

OBDII Code P0139 2006 Ford Fusion - O2 Sensor Circuit Slow Response Bank 1 Sensor 2 - AutoCodes.com — P0139 2006 Ford Fusion Code - O2 Sensor Circuit Slow Response Bank 1 Sensor 2

What does this mean?

What are the Possible Causes of the DTC P0139 2006 Ford Fusion?

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 2006 Ford Fusion?

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 2006 Ford Fusion 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 2006 Ford Fusion Code

1. What does the OBDII code P0139 on a 2006 Ford Fusion indicate?

The P0139 code signifies that the Oxygen Sensor (O2) in Bank 1, Sensor 2 has a slower than normal response time to changes in fuel mixture, indicating potential issues with the sensor or its circuit.

2. Where is Bank 1 Sensor 2 located on a 2006 Ford Fusion?

Bank 1 refers to the side of the engine with the first cylinder. Sensor 2 is the downstream oxygen sensor located after the catalytic converter.

3. What are common symptoms of the P0139 code in a 2006 Ford Fusion?

Symptoms include a check engine light, poor fuel economy, rough engine idle, and sometimes a noticeable drop in engine performance.

4. What could cause the P0139 code to appear on a 2006 Ford Fusion?

Common causes include a faulty oxygen sensor, exhaust leaks near the sensor, damaged or corroded wiring, or problems with the engine's fuel management system.

5. How can I fix the P0139 code on a 2006 Ford Fusion?

Repair options include replacing the oxygen sensor, repairing any leaks in the exhaust system, checking and repairing sensor wiring, and ensuring the fuel system is functioning properly.

6. Is it necessary to replace the O2 sensor immediately if a P0139 code appears?

While the vehicle may still run, it is advisable to address the issue as soon as possible to avoid potential damage to the catalytic converter and to maintain optimal fuel efficiency.

7. How do I confirm that the O2 sensor is the problem when diagnosing code P0139?

Verification can be done using an OBDII scanner to monitor the sensor's voltage output. If the sensor does not respond quickly or adequately to changes in exhaust gas composition, it likely needs replacement.

8. Can driving with a P0139 code damage my 2006 Ford Fusion?

Continuing to drive with this issue can lead to inefficient fuel consumption, higher emissions, and potentially damaging the catalytic converter, leading to more expensive repairs.

9. What tools are required to diagnose and fix a P0139 code?

Tools needed may include an OBDII scanner, digital multimeter, and basic hand tools. For sensor replacement, a specific O2 sensor socket may also be necessary.