AutoCodes – GMC – P11D5 2015 GMC Sierra

P11D5 2015 GMC Sierra Code - NOx Sensor 2 Exceeded Minimum Learning Limit

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: P11D5 2015 GMC Sierra indicates NOx Sensor 2 Exceeded Minimum Learning Limit.
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 177

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 P11D5 2015 GMC Sierra 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 P11D5 2015 GMC Sierra - NOx Sensor 2 Exceeded Minimum Learning Limit - AutoCodes.com — P11D5 2015 GMC Sierra Code - NOx Sensor 2 Exceeded Minimum Learning Limit

What does this mean?

What are the Possible Causes of the DTC P11D5 2015 GMC Sierra?

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 P11D5 2015 GMC Sierra?

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 P11D5 2015 GMC Sierra 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 P11D5 2015 GMC Sierra code?

Need more information on how to fix the P11D5 2015 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the Code?

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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 P11D5 2015 GMC Sierra Code

What does the OBDII code P11D5 mean on a 2015 GMC Sierra?

P11D5 indicates that the NOx Sensor 2 (downstream sensor) has exceeded its minimum learning limit, suggesting a problem with its ability to properly detect nitrogen oxide levels.

What are the common symptoms of code P11D5 on a 2015 GMC Sierra?

Symptoms may include an illuminated check engine light, reduced engine performance, increased emissions, or entering limp mode in severe cases.

What causes the P11D5 code to appear on a 2015 GMC Sierra?

Common causes include a faulty NOx sensor, wiring or connector issues, software calibration errors, or excessive soot buildup affecting sensor performance.

Can a faulty NOx sensor cause engine damage if not repaired?

While it may not directly damage the engine, ignoring the issue can lead to increased emissions, reduced fuel efficiency, and potential damage to the exhaust aftertreatment system over time.

How do you diagnose the P11D5 code on a 2015 GMC Sierra?

Diagnose the issue by scanning for codes, inspecting the NOx sensor and its wiring for damage, checking for exhaust leaks, and verifying proper sensor operation with a scan tool.

Can the P11D5 code be fixed without replacing the NOx sensor?

Yes, in some cases, the issue may be resolved by repairing damaged wiring, cleaning excessive soot buildup, or reprogramming the ECU with updated software.

How much does it cost to replace a NOx sensor on a 2015 GMC Sierra?

Replacing a NOx sensor typically costs between $300 and $800, depending on parts and labor rates in your area.

Is it safe to drive with the P11D5 code active?

Driving with this code is not recommended as it may lead to increased emissions, reduced performance, and potential damage to the exhaust system if not addressed promptly.

Can a software update fix the P11D5 code on a 2015 GMC Sierra?

Yes, in some cases, a software update for the engine control module (ECM) can resolve the issue if it stems from calibration errors.

How can I prevent the P11D5 code from recurring on my GMC Sierra?

Regular maintenance, using high-quality diesel fuel, and ensuring the exhaust system and aftertreatment components are clean and functioning properly can help prevent this code.