AutoCodes – GMC – P013B GMC

P013B GMC Code - HO2S Slow Response Lean to Rich Bank 1 Sensor 2

Quick Answer

The Heated Oxygen Sensors (HO2S) are used for fuel control and catalyst monitoring. Common causes include Faulty Heated Oxygen Bank 1 Sensor 2, Heated Oxygen Bank 1 Sensor 2 harness is open or shorted, Heated Oxygen Bank 1 Sensor 2 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: P013B GMC indicates HO2S Slow Response Lean to Rich Bank 1 Sensor 2.
Common causes: Common causes include Faulty Heated Oxygen Bank 1 Sensor 2, Heated Oxygen Bank 1 Sensor 2 harness is open or shorted, Heated Oxygen Bank 1 Sensor 2 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 7,362

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 May 28, 2022

Description
Possible Causes
How To Fix
Tech Notes ▶
Cost to Diagnose
Comments
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Code P013B GMC Description

The Heated Oxygen Sensors (HO2S) are used for fuel control and catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the Engine Control Module (ECM) operates in an Open Loop mode, ignoring the HO2S signal voltage while calculating the air-to-fuel ratio. While the engine runs, the HO2S heats up and begins to generate a voltage within a range of 0 - 1, 000 mV. Once sufficient HO2S voltage fluctuation is observed by the ECM, Closed Loop is entered. The ECM uses the HO2S voltage to determine the air-to-fuel ratio. An HO2S voltage that increases toward 1, 000 mV indicates a rich fuel mixture. An HO2S voltage that decreases toward 0 mV indicates a lean fuel mixture.
The heating elements inside each HO2S heat the sensor to bring the sensor up to operating conditions faster. This allows the system to enter Closed Loop earlier and the ECM to calculate the air-to-fuel ratio sooner.
The Diagnostic Trouble Code (DTC) will be set when the ECM detects that the accumulated mass airflow monitored during lean-to-rich transitions between 350 - 650 mV is greater than calibrated value.

OBDII Code P013B GMC - HO2S Slow Response Lean to Rich Bank 1 Sensor 2 - AutoCodes.com — P013B GMC Code - HO2S Slow Response Lean to Rich Bank 1 Sensor 2

What does this mean?

What are the Possible Causes of the DTC P013B GMC?

Faulty Heated Oxygen Bank 1 Sensor 2
Heated Oxygen Bank 1 Sensor 2 harness is open or shorted
Heated Oxygen Bank 1 Sensor 2 circuit poor electrical connection
Low or high fuel system pressure
Fuel contamination
Faulty fuel injectors
Exhaust gas leaks
Engine vacuum leaks

How to Fix the DTC P013B GMC?

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 Sensors (HO2S) usually takes care of the problem.

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What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P013B GMC 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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Information for Specific GMC Models

P013B 2014 GMC Sierra — HO2S Slow Response Lean to Rich Bank 1 Sensor 2
P013B 2015 GMC Sierra — HO2S Slow Response Lean to Rich Bank 1 Sensor 2
P013B 2016 GMC Sierra — HO2S Slow Response Lean to Rich Bank 1 Sensor 2
P013B 2017 GMC Sierra — HO2S Slow Response Lean to Rich Bank 1 Sensor 2
P013B 2018 GMC Sierra — HO2S Slow Response Lean to Rich Bank 1 Sensor 2

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.