AutoCodes – GMC – P0155 GMC

P0155 GMC Code - HO2S Heater Performance Bank 2 Sensor 1

Quick Answer

Heated Oxygen Sensors (HO2S) are used for fuel control and post catalyst monitoring. Common causes include Faulty Heated Oxygen Sensor (H2OS) Bank 2 Sensor 1, Heated Oxygen Sensor Bank 2 Sensor 1 harness is open shorted, Heated Oxygen Sensor Bank 2 Sensor 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: P0155 GMC indicates HO2S Heater Performance Bank 2 Sensor 1.
Common causes: Common causes include Faulty Heated Oxygen Sensor (H2OS) Bank 2 Sensor 1, Heated Oxygen Sensor Bank 2 Sensor 1 harness is open shorted, Heated Oxygen Sensor Bank 2 Sensor 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 29,239

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 23, 2024

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes ▶
Cost to Diagnose
FAQs
Comments
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Code P0155 GMC Description

Heated Oxygen Sensors (HO2S) are used for fuel control and post catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content in the exhaust stream. The HO2S must reach an operating temperature to provide an accurate voltage signal. A heating element inside the HO2S minimizes the time required for the sensors to reach operating temperature. Voltage is provided to the heater by an ignition voltage circuit through a fuse. With the engine running, the ground is provided to the heater by the HO2S heater low control circuit through a low side driver within the Engine Control Module (ECM). The ECM uses Pulse Width Modulation (PWM) to control the HO2S heater operation to maintain a specific HO2S operating temperature range.
The Diagnostic Trouble Code (DTC) will be set when the ECM detects that the HO2S 1 heater current is out of factory specifications.

OBDII Code P0155 GMC - HO2S Heater Performance Bank 2 Sensor 1 - AutoCodes.com — P0155 GMC Code - HO2S Heater Performance Bank 2 Sensor 1

What does this mean?

What are the Possible Causes of the DTC P0155 GMC?

Faulty Heated Oxygen Sensor (H2OS) Bank 2 Sensor 1
Heated Oxygen Sensor Bank 2 Sensor 1 harness is open shorted
Heated Oxygen Sensor Bank 2 Sensor 1 circuit poor electrical connection
Heated Oxygen Sensor Bank 2 Sensor 1 circuit fuse
Faulty Engine Control Module (ECM)

How to Fix the DTC P0155 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

The code means that there is a problem with the heater element circuit of the heated oxygen sensor. The control module monitors how long it takes the sensor to warm up and start sending an adequate signal. The code is set when the sensor is taking too long to warm up. Water getting inside the heated oxygen sensor connector can cause the heated oxygen sensor fuse to blow. Before replacing the sensor, check for the condition of the heated oxygen sensor fuse and connectors. If the fuse and connector are OK, replacing the O2 Sensor usually takes care of the problem.

1998 Chevy Tahoe Check Engine Light & Code P0155

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What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0155 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

P0155 2014 GMC Sierra — HO2S Heater Performance Bank 2 Sensor 1
P0155 2015 GMC Sierra — HO2S Heater Performance Bank 2 Sensor 1
P0155 2016 GMC Sierra — HO2S Heater Performance Bank 2 Sensor 1
P0155 2017 GMC Sierra — HO2S Heater Performance Bank 2 Sensor 1
P0155 2018 GMC Sierra — HO2S Heater Performance Bank 2 Sensor 1

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 P0155 GMC Code

1. What are the common symptoms of OBDII code P0155 GMC?

The common symptoms of code P0155 include poor fuel economy, rough idling, engine misfires, and the illumination of the Check Engine Light.

2. What does the OBDII code P0155 GMC indicate?

Code P0155 indicates an issue with the heater performance of the oxygen sensor (HO2S) located in Bank 2 Sensor 1 of the vehicle's exhaust system.

3. What are the possible causes of OBDII code P0155 GMC?

The possible causes of code P0155 include a faulty oxygen sensor, damaged wiring or connectors, a blown fuse, a malfunctioning engine control module (ECM), or issues with the sensor heater circuit.

4. How can I diagnose and repair OBDII code P0155 GMC?

To diagnose and repair code P0155, you can start by checking the oxygen sensor's wiring and connectors for any damage or corrosion. You may also need to test the sensor heater circuit, replace the oxygen sensor if necessary, and reset the Check Engine Light with an OBDII scanner.

5. Can I drive my vehicle with OBDII code P0155 GMC?

It is generally safe to drive your vehicle with code P0155, but it is important to address the issue promptly to prevent potential damage to the catalytic converter and ensure optimal engine performance.

6. How much does it cost to fix OBDII code P0155 GMC?

The cost to fix code P0155 can vary depending on the root cause of the issue. Replacing the oxygen sensor or repairing the sensor heater circuit may cost anywhere from $100 to $300, including parts and labor.

7. Will resetting the Check Engine Light fix OBDII code P0155 GMC?

Simply resetting the Check Engine Light without addressing the underlying issue causing code P0155 will not fix the problem. It is important to diagnose the root cause of the code and make the necessary repairs to prevent it from reoccurring.

8. How often does OBDII code P0155 GMC occur in GMC vehicles?

Code P0155 can occur in GMC vehicles with oxygen sensors, particularly in models equipped with Bank 2 Sensor 1 located in the exhaust system.

9. Can a DIY enthusiast fix OBDII code P0155 GMC?

A knowledgeable DIY enthusiast with the right tools and experience may be able to diagnose and repair code P0155. However, if you are unsure about the process, it is recommended to seek professional help to ensure the issue is properly resolved.

10. Is OBDII code P0155 GMC a serious problem?

While code P0155 may not cause immediate engine failure, it should be addressed promptly to avoid potential long-term damage to the vehicle's emissions system and ensure optimal engine performance.