AutoCodes – Buick – P11C0 Buick

P11C0 Buick Code - O2 Reference Voltage 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: P11C0 Buick indicates O2 Reference Voltage 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.

Save to My Repairs My Repairs

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

Code Popularity 360

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 P11C0 Buick 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 P11C0 Buick - O2 Reference Voltage Circuit High Voltage (NOx Sensor 2) - AutoCodes.com — P11C0 Buick Code - O2 Reference Voltage Circuit High Voltage (NOx Sensor 2)

What does this mean?

What are the Possible Causes of the DTC P11C0 Buick?

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 P11C0 Buick?

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 P11C0 Buick 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 P11C0 Buick code?

Need more information on how to fix the P11C0 Buick code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P11C0 Buick 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 P11C0 Buick Code

1. What are the common symptoms of OBDII code P11C0 in a Buick related to the O2 Reference Voltage Circuit High Voltage (NOx Sensor 2)?

- Common symptoms include poor engine performance, rough idling, decreased fuel efficiency, and the illumination of the check engine light.

2. What are the potential causes of OBDII code P11C0 in a Buick?

- The code P11C0 could be triggered by issues such as a faulty NOx sensor, damaged wiring or connectors in the O2 reference voltage circuit, or a problem with the engine control module (ECM).

3. How can I diagnose OBDII code P11C0 in my Buick related to the O2 Reference Voltage Circuit High Voltage (NOx Sensor 2)?

- Diagnosis typically involves using an OBDII scanner to retrieve the fault code, inspecting the NOx sensor and its wiring for any visible damage, and testing the voltage in the O2 reference circuit.

4. Can I continue driving my Buick with OBDII code P11C0 present?

- It is not recommended to continue driving your vehicle with the code P11C0 active, as it can lead to further damage to the engine and emissions control system.

5. How can I repair OBDII code P11C0 in my Buick related to the O2 Reference Voltage Circuit High Voltage (NOx Sensor 2)?

- Repair options may include replacing the NOx sensor, repairing or replacing damaged wiring or connectors in the O2 reference voltage circuit, and resetting the ECM by clearing the fault code.

6. Are there any DIY tips for addressing OBDII code P11C0 in a Buick?

- While some basic inspections and checks can be done by DIY enthusiasts, it is recommended to consult a professional mechanic for accurate diagnosis and repair of code P11C0 to ensure proper resolution.

7. How much does it typically cost to repair OBDII code P11C0 in a Buick?

- Repair costs for OBDII code P11C0 can vary depending on the exact cause of the issue, but it is advisable to budget for potential NOx sensor replacement or wiring repairs, which could range from a few hundred to over a thousand dollars.

8. Will resetting the check engine light resolve OBDII code P11C0 in a Buick?

- Resetting the check engine light may temporarily turn off the warning indicator, but it will not fix the underlying issue causing OBDII code P11C0. It is crucial to address the root cause of the problem to prevent further complications.

9. How long does it take to repair OBDII code P11C0 in a Buick?

- The repair time for code P11C0 can vary depending on the specific diagnosis and repair steps required. It may take a few hours to a full day for a mechanic to properly diagnose and fix the issue.

10. Can a faulty NOx sensor cause OBDII code P11C0 in a Buick?

- Yes, a faulty NOx sensor is a common cause of OBDII code P11C0 related to the O2 Reference Voltage Circuit High Voltage (NOx Sensor 2) in a Buick.