AutoCodes – GMC – P11C6 GMC

P11C6 GMC Code - NOx Sensor 1 Heater Ground Circuit High

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: P11C6 GMC indicates NOx Sensor 1 Heater Ground Circuit High.
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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 1,442

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Mar 29, 2024

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code P11C6 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 P11C6 GMC - NOx Sensor 1 Heater Ground Circuit High - AutoCodes.com — P11C6 GMC Code - NOx Sensor 1 Heater Ground Circuit High

What does this mean?

What are the Possible Causes of the DTC P11C6 GMC?

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 P11C6 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 P11C6 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 P11C6 GMC code?

Need more information on how to fix the P11C6 GMC code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P11C6 GMC code diagnosed by a professional: Find a repair shop in your area

Information for Specific GMC Models

P11C6 2014 GMC Sierra — NOx Sensor 1 Heater Ground Circuit High
P11C6 2015 GMC Sierra — NOx Sensor 1 Heater Ground Circuit High
P11C6 2016 GMC Sierra — NOx Sensor 1 Heater Ground Circuit High
P11C6 2017 GMC Sierra — NOx Sensor 1 Heater Ground Circuit High
P11C6 2018 GMC Sierra — NOx Sensor 1 Heater Ground Circuit High

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 P11C6 GMC Code

1. What are the common symptoms of OBDII code P11C6 GMC (NOx Sensor 1 Heater Ground Circuit High)?

- Common symptoms include poor engine performance, decreased fuel efficiency, illuminated Check Engine Light, and potential emissions issues.

2. What typically causes the OBDII code P11C6 GMC to trigger?

- The code is usually triggered by a malfunction in the NOx Sensor 1 heater ground circuit, indicating a high voltage condition.

3. How serious is the OBDII code P11C6 GMC (NOx Sensor 1 Heater Ground Circuit High)?

- While the code may not cause immediate drivability issues, it can lead to increased emissions and potential long-term damage if left unresolved.

4. What should I do if my vehicle displays the OBDII code P11C6 GMC?

- It is recommended to have the vehicle diagnosed by a qualified mechanic to pinpoint the exact cause of the issue and determine the necessary repairs.

5. Can I continue driving my vehicle with the OBDII code P11C6 GMC present?

- While you may be able to drive the vehicle, it is advisable to address the underlying problem promptly to prevent any further damage or emissions-related issues.

6. How can I repair the OBDII code P11C6 GMC (NOx Sensor 1 Heater Ground Circuit High)?

- Repair typically involves inspecting the NOx Sensor 1 heater circuit for faults, checking the wiring and connections, and replacing any defective components as needed.

7. Is it possible to reset the OBDII code P11C6 GMC without fixing the issue?

- Simply clearing the code without addressing the root cause will not resolve the underlying problem, and the code is likely to reappear once the issue persists.

8. Are there any DIY tips for troubleshooting the OBDII code P11C6 GMC?

- DIY enthusiasts can start by checking the wiring harness, connectors, and fuses related to the NOx Sensor 1 heater circuit for any visible damage or corrosion.

9. Can extreme weather conditions contribute to the triggering of OBDII code P11C6 GMC?

- Yes, extreme temperatures and environmental factors can sometimes affect the NOx sensor's operation, potentially leading to a high ground circuit voltage condition.

10. How can regular maintenance help prevent the recurrence of the OBDII code P11C6 GMC?

- Regular maintenance, including inspecting and cleaning sensor connections, can help prevent issues like the NOx Sensor 1 Heater Ground Circuit High from occurring.