AutoCodes – Chevrolet – P11D8 Chevrolet

P11D8 Chevrolet Code - O2 Pump Current Control 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: P11D8 Chevrolet indicates O2 Pump Current Control 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.

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Code Popularity 1,248

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 P11D8 Chevrolet 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 P11D8 Chevrolet - O2 Pump Current Control Circuit (NOx Sensor 2) - AutoCodes.com — P11D8 Chevrolet Code - O2 Pump Current Control Circuit (NOx Sensor 2)

What does this mean?

What are the Possible Causes of the DTC P11D8 Chevrolet?

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 P11D8 Chevrolet?

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 P11D8 Chevrolet 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 P11D8 Chevrolet code?

Need more information on how to fix the P11D8 Chevrolet code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P11D8 Chevrolet code diagnosed by a professional: Find a repair shop in your area

Information for Specific Chevrolet Models

P11D8 2014 Chevrolet Silverado — O2 Pump Current Control Circuit (NOx Sensor 2)
P11D8 2015 Chevrolet Silverado — O2 Pump Current Control Circuit (NOx Sensor 2)
P11D8 2016 Chevrolet Silverado — O2 Pump Current Control Circuit (NOx Sensor 2)
P11D8 2017 Chevrolet Silverado — O2 Pump Current Control Circuit (NOx Sensor 2)
P11D8 2018 Chevrolet Silverado — O2 Pump Current Control 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 P11D8 Chevrolet Code

1. What are the common symptoms of OBDII code P11D8 in a Chevrolet related to the O2 Pump Current Control Circuit (NOx Sensor 2)?

The common symptoms include poor engine performance, decreased fuel efficiency, rough idling, and the illumination of the Check Engine Light.

2. What are the possible causes of OBDII code P11D8 in a Chevrolet indicating an issue with the O2 Pump Current Control Circuit (NOx Sensor 2)?

Potential causes can be a faulty NOx sensor, damaged wiring or connectors in the circuit, a malfunctioning O2 pump, or a problem with the engine control module.

3. How can I diagnose the O2 Pump Current Control Circuit issue causing OBDII code P11D8 in my Chevrolet?

Diagnosing this issue typically involves using a scan tool to retrieve the trouble codes, testing the NOx sensor and O2 pump, inspecting the wiring and connectors, and checking the engine control module for any faults.

4. What are the repair options for resolving OBDII code P11D8 related to the O2 Pump Current Control Circuit in a Chevrolet?

Depending on the root cause, repairs may involve replacing the NOx sensor, repairing or replacing damaged wiring and connectors, fixing or replacing the O2 pump, or reprogramming the engine control module.

5. Can driving with OBDII code P11D8 related to the O2 Pump Current Control Circuit issue harm my Chevrolet?

Continuing to drive with this issue may lead to further damage to the engine components and emission control system, potentially resulting in more costly repairs over time.

6. How urgent is it to address OBDII code P11D8 in a Chevrolet related to the O2 Pump Current Control Circuit?

It is recommended to address this issue promptly to prevent potential engine performance issues, reduced fuel efficiency, and further damage to emission control components.

7. Is it possible to reset the Check Engine Light after resolving OBDII code P11D8 in a Chevrolet?

Yes, once the underlying issue causing the code has been repaired, the Check Engine Light can be reset using a scan tool to clear the trouble code from the vehicle's system.

8. Are there any maintenance tips to prevent O2 Pump Current Control Circuit issues leading to OBDII code P11D8 in a Chevrolet?

Regularly inspecting and maintaining the emission control system components, such as the NOx sensor and O2 pump, can help prevent issues that trigger this trouble code.

9. Can extreme weather conditions affect the O2 Pump Current Control Circuit and trigger OBDII code P11D8 in a Chevrolet?

Yes, extreme temperatures or harsh environmental conditions can potentially impact the performance of the emission control system components, leading to issues like the one indicated by this trouble code.

10. How long does it typically take to repair OBDII code P11D8 in a Chevrolet caused by the O2 Pump Current Control Circuit issue?

The repair time can vary depending on the exact cause of the problem and the complexity of the repair process but may range from a few hours to a full day at a professional repair shop.