AutoCodes – Chevrolet – P11BF 2018 Chevrolet Silverado

P11BF 2018 Chevrolet Silverado Code - O2 Reference Voltage Circuit Low 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: P11BF 2018 Chevrolet Silverado indicates O2 Reference Voltage Circuit Low 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 331

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 P11BF 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 P11BF 2018 Chevrolet Silverado - O2 Reference Voltage Circuit Low Voltage (NOx Sensor 2) - AutoCodes.com — P11BF 2018 Chevrolet Silverado Code - O2 Reference Voltage Circuit Low Voltage (NOx Sensor 2)

What does this mean?

What are the Possible Causes of the DTC P11BF 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 P11BF 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 P11BF 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 P11BF 2018 Chevrolet Silverado code?

Need more information on how to fix the P11BF 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 P11BF 2018 Chevrolet Silverado Code

1. What are the common symptoms of OBDII code P11BF in a 2018 Chevrolet Silverado?

- Common symptoms may include poor engine performance, decreased fuel efficiency, rough idling, and illuminated Check Engine light.

2. What does the O2 Reference Voltage Circuit Low Voltage (NOx Sensor 2) code P11BF indicate in a 2018 Chevrolet Silverado?

- This code indicates that there is a low voltage condition in the O2 reference voltage circuit for NOx Sensor 2 in the vehicle's emissions system.

3. What are some possible causes of OBDII code P11BF in a 2018 Chevrolet Silverado?

- Possible causes may include faulty NOx Sensor 2, damaged wiring or connectors in the O2 reference voltage circuit, or issues with the vehicle's engine control module (ECM).

4. How can I diagnose the O2 Reference Voltage Circuit Low Voltage code P11BF in my 2018 Chevrolet Silverado?

- Diagnosing this code typically involves using a diagnostic scanner to retrieve the specific fault code, checking the wiring and connectors for any visible damage, and testing the NOx Sensor 2 for proper operation.

5. Can I continue driving my 2018 Chevrolet Silverado with OBDII code P11BF present?

- It is not recommended to continue driving with this code present, as it can lead to further damage to the emissions system and potentially affect the vehicle's overall performance.

6. How can I repair OBDII code P11BF in my 2018 Chevrolet Silverado?

- Repairing this code may involve replacing the faulty NOx Sensor 2, repairing or replacing damaged wiring or connectors in the O2 reference voltage circuit, or reprogramming the engine control module if necessary.

7. Are there any DIY tips for troubleshooting O2 Reference Voltage Circuit Low Voltage code P11BF in a 2018 Chevrolet Silverado?

- DIY tips include checking for loose or damaged wiring, ensuring connectors are securely plugged in, and following the manufacturer's diagnostic procedures outlined in the vehicle's service manual.

8. How much does it typically cost to repair OBDII code P11BF in a 2018 Chevrolet Silverado?

- The cost of repairing this code can vary depending on the specific cause and parts needed, but it may range from $200 to $600 or more, including parts and labor.

9. Can a mechanic reset the Check Engine light after fixing OBDII code P11BF in a 2018 Chevrolet Silverado?

- Yes, a mechanic can reset the Check Engine light using a diagnostic scanner after successfully repairing the underlying issue causing code P11BF in the vehicle.

10. How often does OBDII code P11BF occur in a 2018 Chevrolet Silverado, and is it a common issue?

- OBDII code P11BF related to the O2 Reference Voltage Circuit Low Voltage (NOx Sensor 2) is not as common as some other codes, but it can still occur due to sensor or wiring issues in the emissions system of a 2018 Chevrolet Silverado.