AutoCodes – Generic – P11BE

P11BE Code - O2 Reference Voltage 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: P11BE indicates O2 Reference Voltage 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 4,846

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 P11BE 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 P11BE - O2 Reference Voltage Circuit (NOx Sensor 2) - AutoCodes.com — P11BE Code - O2 Reference Voltage Circuit (NOx Sensor 2)

What does this mean?

What are the Possible Causes of the DTC P11BE?

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 P11BE?

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 P11BE 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 P11BE code?

Need more information on how to fix the P11BE code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P11BE code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

P11BE Buick — O2 Reference Voltage Circuit (NOx Sensor 2)
P11BE Cadillac — O2 Reference Voltage Circuit (NOx Sensor 2)
P11BE Chevrolet — O2 Reference Voltage Circuit (NOx Sensor 2)
P11BE GMC — O2 Reference Voltage 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 P11BE Code

1. What are the common symptoms of OBDII code P11BE (O2 Reference Voltage Circuit - NOx Sensor 2)?

The common symptoms include poor engine performance, decreased fuel efficiency, and possibly an illuminated check engine light.

2. What could cause the OBDII code P11BE to trigger?

The code P11BE can be triggered by issues such as a faulty NOx sensor, damaged wiring, a defective oxygen sensor, or a problem with the vehicle's electronic control module (ECM).

3. How can I diagnose the O2 Reference Voltage Circuit issue related to NOx Sensor 2?

Diagnosing the problem involves using an OBDII scanner to retrieve the fault code, performing a visual inspection of the wiring and sensors, and conducting voltage tests to pinpoint the exact issue.

4. Can a DIY enthusiast repair the OBDII code P11BE at home?

While some basic troubleshooting like checking the wiring connections can be done at home, repairing the O2 Reference Voltage Circuit issue may require specialized tools and expertise, so it's recommended to seek professional help.

5. Is it safe to continue driving with the OBDII code P11BE present?

It is not recommended to continue driving with the code P11BE active, as it can lead to more serious engine problems and potentially harm the environment due to increased emissions.

6. How much does it typically cost to repair the O2 Reference Voltage Circuit issue causing the code P11BE?

The cost of repair can vary depending on the exact cause of the issue, but it may range from $100 to $500 or more, including parts and labor.

7. Can a bad NOx sensor cause other issues in the vehicle besides triggering the OBDII code P11BE?

Yes, a malfunctioning NOx sensor can affect the vehicle's emission levels, engine performance, and fuel efficiency, so it's important to address the issue promptly.

8. Are there any preventive measures to avoid encountering the O2 Reference Voltage Circuit problem in the future?

Regular maintenance of the emission control system, including inspecting and replacing sensors as recommended by the manufacturer, can help prevent issues like the OBDII code P11BE from occurring.

9. How long does it typically take to repair the O2 Reference Voltage Circuit issue causing the code P11BE?

The repair time can vary based on the specific cause of the problem, but it may take anywhere from a few hours to a full day to diagnose and fix the issue.

10. Can resetting the check engine light resolve the OBDII code P11BE temporarily?

Resetting the check engine light may temporarily clear the code P11BE, but if the underlying issue is not addressed, the code is likely to reappear. It's important to diagnose and repair the root cause of the problem.