AutoCodes – GMC – P11C5 2017 GMC Sierra

P11C5 2017 GMC Sierra Code - NOx Sensor 1 Heater Ground Circuit

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, Nitrogen Oxides Sensor harness is open or shorted, Nitrogen Oxides Sensor 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: P11C5 2017 GMC Sierra indicates NOx Sensor 1 Heater Ground Circuit.
Common causes: Common causes include Faulty Nitrogen Oxides (NOx) Sensor, Nitrogen Oxides Sensor harness is open or shorted, Nitrogen Oxides Sensor 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 206

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 P11C5 2017 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 P11C5 2017 GMC Sierra - NOx Sensor 1 Heater Ground Circuit - AutoCodes.com — P11C5 2017 GMC Sierra Code - NOx Sensor 1 Heater Ground Circuit

What does this mean?

What are the Possible Causes of the DTC P11C5 2017 GMC Sierra?

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

How to Fix the DTC P11C5 2017 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 P11C5 2017 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 P11C5 2017 GMC Sierra code?

Need more information on how to fix the P11C5 2017 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P11C5 2017 GMC Sierra code diagnosed by a professional: Find a repair shop in your area

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 P11C5 2017 GMC Sierra Code

1. What does OBDII code P11C5 mean on a 2017 GMC Sierra?

P11C5 indicates an issue with the NOx Sensor 1 Heater Ground Circuit, which means the vehicle's control module has detected a malfunction in the heater ground circuit of the NOx sensor.

2. What are the symptoms of code P11C5 on a 2017 GMC Sierra?

Symptoms may include an illuminated Check Engine Light, reduced engine performance, increased emissions, and possible issues with the vehicleâ€™s DEF (Diesel Exhaust Fluid) system.

3. What causes code P11C5 to appear?

Common causes include a damaged NOx sensor, a broken or corroded ground wire, a faulty heater circuit in the sensor, or issues with the vehicle's wiring or connectors.

4. Can I still drive my 2017 GMC Sierra with code P11C5?

While the vehicle may still be drivable, ignoring the issue can lead to increased emissions, reduced fuel efficiency, and potential damage to the exhaust aftertreatment system.

5. How is code P11C5 diagnosed?

A technician will use a diagnostic scan tool to confirm the code, inspect the wiring and connectors for damage or corrosion, and test the NOx sensor heater circuit for proper functionality.

6. How do I fix code P11C5 on a 2017 GMC Sierra?

Repairs may involve replacing the NOx sensor, repairing damaged wiring or connectors, or addressing any issues with the vehicleâ€™s electrical ground connections.

7. How much does it cost to fix code P11C5 on a 2017 GMC Sierra?

The cost depends on the exact repair needed. Replacing the NOx sensor can cost between $300 and $700, while wiring repairs may cost less.

8. Can a bad NOx sensor cause other problems in my 2017 GMC Sierra?

Yes, a faulty NOx sensor can disrupt the diesel engine's emissions control system, leading to increased emissions and possible DEF system malfunctions.

9. How can I prevent code P11C5 from occurring again?

Regular maintenance, inspecting the NOx sensor wiring and connectors for damage, and addressing electrical issues promptly can help prevent this code from reappearing.

10. Is code P11C5 covered under warranty for my 2017 GMC Sierra?

Depending on the mileage and warranty coverage, the repair may be covered under an emissions warranty. Check with your dealership for specific details.