AutoCodes – Chevrolet – P11FC Chevrolet

P11FC Chevrolet Code - O2 Low Reference 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: P11FC Chevrolet indicates O2 Low Reference 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 359

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 24, 2024

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P11FC Chevrolet 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 P11FC Chevrolet - O2 Low Reference Circuit (NOx Sensor 2) - AutoCodes.com — P11FC Chevrolet Code - O2 Low Reference Circuit (NOx Sensor 2)

What does this mean?

What are the Possible Causes of the DTC P11FC Chevrolet?

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 P11FC Chevrolet?

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 P11FC Chevrolet 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 P11FC Chevrolet code?

Need more information on how to fix the P11FC Chevrolet code? Get Access to Factory Service Manuals

Need Help with the Code?

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Information for Specific Chevrolet Models

P11FC 2014 Chevrolet Silverado — O2 Low Reference Circuit (NOx Sensor 2)
P11FC 2015 Chevrolet Silverado — O2 Low Reference Circuit (NOx Sensor 2)
P11FC 2016 Chevrolet Silverado — O2 Low Reference Circuit (NOx Sensor 2)
P11FC 2017 Chevrolet Silverado — O2 Low Reference Circuit (NOx Sensor 2)
P11FC 2018 Chevrolet Silverado — O2 Low Reference 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 P11FC Chevrolet Code

1. What are the common symptoms of OBDII code P11FC in a Chevrolet related to the O2 Low Reference Circuit (NOx Sensor 2)?

- Common symptoms include poor engine performance, reduced fuel efficiency, and possibly an illuminated Check Engine light.

2. What can cause the OBDII code P11FC to trigger in a Chevrolet?

- The code P11FC is typically triggered by issues with the O2 Low Reference Circuit, such as wiring faults, sensor malfunctions, or problems with the NOx sensor itself.

3. How serious is the O2 Low Reference Circuit issue indicated by code P11FC in a Chevrolet?

- While the issue may not cause immediate harm to the vehicle, it can lead to poor engine performance, reduced fuel efficiency, and may affect the vehicle's emissions.

4. How can I diagnose the O2 Low Reference Circuit problem causing code P11FC in my Chevrolet?

- Diagnosis typically involves checking the wiring and connections related to the NOx sensor, testing the sensor's functionality, and using a diagnostic scanner to read live data.

5. Are there any DIY repair tips for fixing the O2 Low Reference Circuit problem associated with code P11FC in a Chevrolet?

- DIY repairs may include checking and repairing any damaged wiring, cleaning or replacing the NOx sensor, and clearing the error code with an OBDII scanner.

6. Can I continue driving my Chevrolet with the OBDII code P11FC related to the O2 Low Reference Circuit issue?

- It is generally not recommended to continue driving with the code unresolved, as it may lead to further engine problems and increased emissions.

7. How much does it typically cost to repair the O2 Low Reference Circuit issue causing code P11FC in a Chevrolet?

- Repair costs can vary depending on the exact cause of the issue, but it may range from a simple sensor replacement to more extensive wiring repairs, potentially costing a few hundred dollars.

8. Will resetting the Check Engine light resolve the OBDII code P11FC issue in a Chevrolet?

- Resetting the Check Engine light may temporarily clear the code, but if the underlying issue with the O2 Low Reference Circuit is not fixed, the code is likely to reappear.

9. Is it safe to drive my Chevrolet if the O2 Low Reference Circuit issue causing code P11FC has been fixed?

- Once the issue has been properly diagnosed and repaired, it should be safe to drive the vehicle, but it's always recommended to perform regular maintenance checks.

10. Can a faulty NOx sensor cause other problems in a Chevrolet besides triggering the OBDII code P11FC?

- Yes, a faulty NOx sensor can lead to issues such as increased emissions, reduced fuel efficiency, and potential damage to other engine components if left unresolved.