AutoCodes – GMC – P11D0 GMC

P11D0 GMC Code - O2 Signal Circuit (NOx Sensor 2)

Quick Answer

The Nitrogen Oxides (NOx) sensors are part of the selective catalytic reduction system, a device used to reduce NOx emission on diesel engines. Common causes include Faulty Nitrogen Oxides (NOx) Sensor 2, Nitrogen Oxides Sensor 2 harness is open or shorted, Nitrogen Oxides Sensor 2 circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P11D0 GMC indicates O2 Signal Circuit (NOx Sensor 2).
Common causes: Common causes include Faulty Nitrogen Oxides (NOx) Sensor 2, Nitrogen Oxides Sensor 2 harness is open or shorted, Nitrogen Oxides Sensor 2 circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 362

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

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Table of contents Created and updated by William Orellana on Mar 24, 2024

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P11D0 GMC Description

The Nitrogen Oxides (NOx) sensors are part of the selective catalytic reduction system, a device used to reduce NOx emission on diesel engines. There are two NOx sensors, one placed upstream of selective catalytic reduction, to measure inlet NOx concentration, and one placed downstream. They are connected with the control module via CAN and all the information is exchanged through it. Since it is a smart sensor, all the electrical monitoring is performed inside the sensor and only the results are sent to the Engine Control Module (ECM). Each NOx sensor contains a sensing cell, a pumping cell, and a heater. A sample of exhaust gas passes through a diffusion gap between the sensing cell and the pumping cell. The NOx sensor maintains a constant reference voltage across the sensing cell. An electronic circuit within the sensor controls the pump current through the pumping cell in order to maintain a constant voltage in the sensing cell. The amount of current required to maintain the reference voltage in the sensing cell is proportional to the concentration of NOx in the exhaust. The ECM varies the amount of diesel exhaust fluid (reductant) added by varying the reductant injector duty cycle in response to changes in engine exhaust NOx levels. The smart NOx sensors consist of two components, the NOx module and the NOx sensor element that are serviced as a unit. A circuit or performance condition with a NOx sensor is detected by the NOx sensor module. The smart NOx sensor module communicates the condition to the ECM over the serial data line. The ECM sets a DTC when a serial data message is received from the NOx sensor module. The Diagnostic Trouble Code (DTC) will be set if the ECM software detects a fault in the NOx sensor circuitry or a performance fault in the NOx sensor for greater than 2 s.

OBDII Code P11D0 GMC - O2 Signal Circuit (NOx Sensor 2) - AutoCodes.com — P11D0 GMC Code - O2 Signal Circuit (NOx Sensor 2)

What does this mean?

What are the Possible Causes of the DTC P11D0 GMC?

Faulty Nitrogen Oxides (NOx) Sensor 2
Nitrogen Oxides Sensor 2 harness is open or shorted
Nitrogen Oxides Sensor 2 circuit poor electrical connection

How to Fix the DTC P11D0 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 is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P11D0 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.

Need more information about the P11D0 GMC code?

Need more information on how to fix the P11D0 GMC code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P11D0 GMC code diagnosed by a professional: Find a repair shop in your area

Information for Specific GMC Models

P11D0 2014 GMC Sierra — O2 Signal Circuit (NOx Sensor 2)
P11D0 2015 GMC Sierra — O2 Signal Circuit (NOx Sensor 2)
P11D0 2016 GMC Sierra — O2 Signal Circuit (NOx Sensor 2)
P11D0 2017 GMC Sierra — O2 Signal Circuit (NOx Sensor 2)
P11D0 2018 GMC Sierra — O2 Signal Circuit (NOx 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.

Frequently Asked Questions about P11D0 GMC Code

1. What are the common symptoms of OBDII code P11D0 in a GMC related to the O2 Signal Circuit (NOx Sensor 2)?

The common symptoms include poor fuel efficiency, decreased engine performance, and the illumination of the Check Engine Light.

2. What are some possible causes of OBDII code P11D0 GMC indicating an issue with the NOx Sensor 2?

Possible causes include a faulty NOx sensor, damaged wiring or connectors in the O2 signal circuit, or a problem with the engine control module.

3. How serious is OBDII code P11D0 related to the NOx Sensor 2 in a GMC vehicle?

While the vehicle may still be driveable with this code, it is important to address it promptly to prevent any potential damage to the engine and emissions system.

4. Can I continue driving my GMC with OBDII code P11D0 present?

It is recommended to limit driving and have the issue diagnosed and repaired as soon as possible to avoid further complications and potential damage to the vehicle.

5. What is the typical repair process for OBDII code P11D0 GMC related to the O2 Signal Circuit (NOx Sensor 2)?

The repair process usually involves diagnosing the issue with the NOx sensor, inspecting wiring and connectors, and replacing any faulty components as needed.

6. How can I troubleshoot OBDII code P11D0 in my GMC myself?

You can start by checking the wiring and connectors related to the NOx Sensor 2, ensuring they are in good condition and properly connected. If no visible issues are found, it is recommended to seek professional help for further diagnosis.

7. Will resetting the Check Engine Light make OBDII code P11D0 GMC go away?

Resetting the Check Engine Light may temporarily clear the code, but it will likely reappear if the underlying issue with the NOx Sensor 2 is not addressed.

8. Are there any tips to prevent OBDII code P11D0 from occurring in the future?

Regular maintenance of your vehicle, including checking and replacing sensors as recommended by the manufacturer, can help prevent issues like OBDII code P11D0 related to the NOx Sensor 2.

9. Can a faulty NOx sensor cause other problems in a GMC besides triggering OBDII code P11D0?

Yes, a faulty NOx sensor can potentially affect the vehicle's emissions, engine performance, and fuel efficiency, highlighting the importance of addressing the issue promptly.

10. Is it necessary to visit a dealership for OBDII code P11D0 GMC repair, or can an independent mechanic handle it?

An independent mechanic with experience in diagnosing and repairing OBDII codes should be able to handle the repair for code P11D0 related to the NOx Sensor 2, potentially offering a more cost-effective solution compared to dealership services.