AutoCodes – Chevrolet – P11FC 2018 Chevrolet Silverado

P11FC 2018 Chevrolet Silverado 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 2018 Chevrolet Silverado 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.

Save to My Repairs My Repairs

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

Code Popularity 222

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
Add Comment

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

Code P11FC 2018 Chevrolet Silverado 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 2018 Chevrolet Silverado - O2 Low Reference Circuit (NOx Sensor 2) - AutoCodes.com — P11FC 2018 Chevrolet Silverado Code - O2 Low Reference Circuit (NOx Sensor 2)

What does this mean?

What are the Possible Causes of the DTC P11FC 2018 Chevrolet Silverado?

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 2018 Chevrolet Silverado?

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 2018 Chevrolet Silverado 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 2018 Chevrolet Silverado code?

Need more information on how to fix the P11FC 2018 Chevrolet Silverado code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P11FC 2018 Chevrolet Silverado 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 P11FC 2018 Chevrolet Silverado Code

1. What does the OBDII code P11FC mean on a 2018 Chevrolet Silverado?

P11FC indicates an issue with the O2 low reference circuit of NOx Sensor 2, suggesting a problem with the sensor's ability to measure nitrogen oxide levels accurately.

2. What are the symptoms of code P11FC in a 2018 Chevrolet Silverado?

Common symptoms include reduced fuel efficiency, poor engine performance, an illuminated check engine light, and possible emissions system warnings.

3. What causes the P11FC code to appear in a 2018 Chevrolet Silverado?

Causes may include a faulty NOx Sensor 2, damaged wiring or connectors in the O2 low reference circuit, or issues with the engine control module (ECM).

4. Can I drive my 2018 Chevrolet Silverado with the P11FC code?

While the vehicle may still be drivable, continuing to drive with this code could lead to increased emissions, poorer fuel economy, and potential damage to the emissions system.

5. How is the P11FC code diagnosed in a 2018 Chevrolet Silverado?

Diagnosis involves scanning for codes, inspecting the wiring and connectors for damage, testing the NOx sensor, and verifying proper communication with the ECM.

6. How do I fix the P11FC code on a 2018 Chevrolet Silverado?

Repairs may include replacing the faulty NOx Sensor 2, repairing damaged wiring or connectors, or reprogramming/updating the ECM if necessary.

7. How much does it cost to fix a P11FC code on a 2018 Chevrolet Silverado?

Repair costs vary but may range from $200 to $800 depending on whether the NOx sensor or wiring needs replacement and labor charges in your area.

8. What is the role of NOx Sensor 2 in a 2018 Chevrolet Silverado?

NOx Sensor 2 measures nitrogen oxide levels in the exhaust to help the ECM optimize emissions control and ensure compliance with environmental standards.

9. Can a failing NOx sensor damage my 2018 Chevrolet Silveradoâ€™s engine?

While a failing NOx sensor wonâ€™t directly damage the engine, it can cause increased emissions, reduced fuel efficiency, and strain on the emissions system.

10. Is a P11FC code covered under warranty for a 2018 Chevrolet Silverado?

It may be covered under the emissions warranty if your vehicle is within the warranty period. Check with your dealership for confirmation.