AutoCodes – Chevrolet – P11FE 2018 Chevrolet Silverado

P11FE 2018 Chevrolet Silverado Code - O2 Low Reference Circuit High Voltage (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: P11FE 2018 Chevrolet Silverado indicates O2 Low Reference Circuit High Voltage (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 226

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 P11FE 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 P11FE 2018 Chevrolet Silverado - O2 Low Reference Circuit High Voltage (NOx Sensor 2) - AutoCodes.com — P11FE 2018 Chevrolet Silverado Code - O2 Low Reference Circuit High Voltage (NOx Sensor 2)

What does this mean?

What are the Possible Causes of the DTC P11FE 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 P11FE 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 P11FE 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 P11FE 2018 Chevrolet Silverado code?

Need more information on how to fix the P11FE 2018 Chevrolet Silverado code? Get Access to Factory Service Manuals

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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 P11FE 2018 Chevrolet Silverado Code

1. What does OBDII code P11FE mean on a 2018 Chevrolet Silverado?

Code P11FE indicates "O2 Low Reference Circuit High Voltage" for NOx Sensor 2, which means the low reference circuit for the oxygen sensor is experiencing a higher voltage than expected.

2. What are the symptoms of code P11FE in a 2018 Chevrolet Silverado?

Common symptoms include the check engine light turning on, reduced fuel efficiency, decreased engine performance, and potentially entering limp mode.

3. What causes code P11FE in a 2018 Chevrolet Silverado?

Potential causes include a faulty NOx sensor 2, wiring issues such as damaged or corroded connections, or a malfunctioning engine control module (ECM).

4. How can I diagnose code P11FE on my 2018 Chevrolet Silverado?

Start by visually inspecting the wiring and connectors for NOx Sensor 2. Use a multimeter to check for proper voltage and continuity. If no issues are found, test or replace the sensor.

5. Can I drive my 2018 Chevrolet Silverado with a P11FE code?

Driving with this code is not recommended, as it may lead to reduced performance, higher emissions, and potential damage to the exhaust system.

6. How much does it cost to fix code P11FE on a 2018 Chevrolet Silverado?

Repair costs vary, but replacing the NOx sensor typically costs $200â€“$400 for parts and labor. Wiring repairs or ECM replacement may cost more.

7. Is the NOx Sensor 2 the same as an oxygen sensor?

No, NOx sensors measure nitrogen oxide levels in the exhaust, whereas oxygen sensors measure oxygen levels. Both contribute to emissions control.

8. How do I reset the check engine light after fixing code P11FE?

Use an OBDII scanner to clear the code after repairs. If the issue is resolved, the light should not return.

9. Can a dirty exhaust system cause code P11FE?

While unlikely, excessive soot or contamination in the exhaust system can interfere with sensor readings and should be inspected if other causes are ruled out.

10. Do I need to update the ECM software to fix code P11FE?

In some cases, ECM reprogramming or software updates may be necessary if the issue is related to a software glitch. Check with a dealership for updates.