Engine-CodesGMC – P0138 2016 GMC Sierra

P0138 2016 GMC Sierra Code - HO2S Circuit High Voltage Bank 1 Sensor 2

Quick Answer

The P0138 diagnostic trouble code (DTC) for a 2016 GMC Sierra refers to a "HO2S Circuit High Voltage Bank 1 Sensor 2" issue. Common causes include Faulty oxygen sensor, Wiring or connector issues, Exhaust leaks. 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
P0138 2016 GMC Sierra indicates HO2S Circuit High Voltage Bank 1 Sensor 2.
Common causes
Common causes include Faulty oxygen sensor, Wiring or connector issues, Exhaust leaks.
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.
Table of contents Created and updated by William Orellana on Aug 18, 2024
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Code P0138 2016 GMC Sierra Description

The P0138 diagnostic trouble code (DTC) for a 2016 GMC Sierra refers to a "HO2S Circuit High Voltage Bank 1 Sensor 2" issue. This code indicates that there is a problem with the oxygen sensor (O2 sensor) located downstream of the catalytic converter on the bank 1 side of the engine. The O2 sensor is responsible for measuring the amount of oxygen in the exhaust gases, which helps the engine control module (ECM) adjust the air-fuel mixture for optimal combustion. When the voltage from the O2 sensor is higher than normal, it can lead to various issues with the vehicle's performance and emissions.

OBDII Code P0138 2016 GMC Sierra - HO2S Circuit High Voltage Bank 1 Sensor 2
P0138 2016 GMC Sierra Code - HO2S Circuit High Voltage Bank 1 Sensor 2

Common Causes of P0138 2016 GMC Sierra

  1. Faulty oxygen sensor
  2. Wiring or connector issues
  3. Exhaust leaks
  4. Engine misfire
  5. Vacuum leaks

Symptoms of P0138 2016 GMC Sierra

  1. Decreased fuel efficiency
  2. Rough idling or stalling
  3. Check Engine Light illuminated
  4. Poor acceleration or hesitation
  5. Increased emissions

How to Fix P0138 2016 GMC Sierra

  1. Use an OBD-II scanner to confirm the P0138 code and identify the specific sensor causing the issue.
  2. Inspect the wiring and connectors for any damage or corrosion, repairing or replacing as needed.
  3. Check for exhaust leaks and repair them if present.
  4. Test the oxygen sensor with a multimeter to determine if it is functioning properly. Replace the sensor if necessary.
  5. Clear the code from the ECM and perform a test drive to ensure the issue has been resolved.

Cost to Fix P0138 2016 GMC Sierra

The cost of repairing a P0138 code on a 2016 GMC Sierra can vary depending on the specific cause of the issue and the cost of parts and labor in your area. Typically, replacing an oxygen sensor can range from $100 to $300, while addressing wiring or connector issues may cost between $50 to $150. Additionally, labor costs can add up, with hourly rates ranging from $80 to $150. It's advisable to consult with a professional mechanic to get an accurate estimate based on your specific situation.

Tech Notes for P0138 2016 GMC Sierra

Replacing the Rear Heated Oxygen Sensor (HO2S) Bank 1 usually takes care of the problem.





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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.

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