AutoCodes.com
Login with Google
AutoCodes – GMC – P11DC GMC

P11DC GMC Code - NOx Sensor 2 Current Performance

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
P11DC GMC indicates NOx Sensor 2 Current Performance.
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.
Save to My Repairs My Repairs
AI answers can be wrong. Verify repairs with testing. Open full chat
Code Popularity 4,889
How popular is this code, among other codes? Low
What is this?
Table of contents Created and updated by William Orellana on Mar 24, 2024
💬 Need more help? Ask Coddy for instant answers — it's free!

Code P11DC 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 P11DC GMC - NOx Sensor 2 Current Performance - AutoCodes.com
P11DC GMC Code - NOx Sensor 2 Current Performance
What does this mean?

What are the Possible Causes of the DTC P11DC 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 P11DC 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 P11DC 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 P11DC GMC code?

Need more information on how to fix the P11DC GMC code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P11DC GMC code diagnosed by a professional: Find a repair shop in your area

Information for Specific GMC Models

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 P11DC GMC Code

1. What does the OBDII code P11DC mean on a GMC?

The P11DC code indicates an issue with the performance of NOx Sensor 2, specifically related to its current output or operation.

2. What are the symptoms of a P11DC code on a GMC?

Common symptoms include reduced fuel efficiency, increased emissions, illumination of the check engine light, and potential loss of engine power.

3. What causes the P11DC code to appear on a GMC vehicle?

The code can be triggered by a malfunctioning NOx sensor, wiring issues, poor electrical connections, or a problem with the exhaust system.

4. Can a dirty or clogged exhaust system trigger the P11DC code?

Yes, a clogged exhaust or catalytic converter can impact NOx sensor readings and contribute to this code.

5. How is the P11DC code diagnosed?

Technicians use an OBDII scanner to retrieve the code, inspect the NOx sensor and wiring, and may perform tests on the exhaust system for proper operation.

6. Can I drive my GMC with the P11DC code active?

It’s possible to drive short distances, but prolonged operation can lead to increased emissions and potential engine damage if not repaired promptly.

7. How do you fix the P11DC code on a GMC?

Repairs may involve replacing the NOx sensor, repairing damaged wiring, or addressing any exhaust system issues.

8. How much does it cost to fix a P11DC code on a GMC?

The cost varies but typically ranges from $300 to $800, depending on whether the NOx sensor or other components need replacement.

9. Can a software update fix the P11DC code on a GMC?

In some cases, a software update to the engine control module (ECM) can resolve the issue if the problem lies in incorrect sensor calibration.

10. How can I prevent the P11DC code on my GMC?

Regular maintenance, including exhaust inspections and timely replacement of sensors, can help prevent this code from appearing.

Discuss the causes and fixes for P11DC GMC OBDII Code

Submit a New Comment

Code P11DC GMC comments

No comments found for this page.

AutoCodes App

Fix Your Car Smarter

Try the New AutoCodes App!

Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.

AutoCodes App on Google Play