AutoCodes – Generic – P11D5

P11D5 Code - NOx Sensor 2 Exceeded Minimum Learning Limit

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: P11D5 indicates NOx Sensor 2 Exceeded Minimum Learning Limit.
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 10,854

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
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Code P11D5 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 P11D5 - NOx Sensor 2 Exceeded Minimum Learning Limit - AutoCodes.com — P11D5 Code - NOx Sensor 2 Exceeded Minimum Learning Limit

What does this mean?

What are the Possible Causes of the DTC P11D5?

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 P11D5?

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 P11D5 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 P11D5 code?

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Information for Specific Makes

P11D5 Buick — NOx Sensor 2 Exceeded Minimum Learning Limit
P11D5 Cadillac — NOx Sensor 2 Exceeded Minimum Learning Limit
P11D5 Chevrolet — NOx Sensor 2 Exceeded Minimum Learning Limit
P11D5 GMC — NOx Sensor 2 Exceeded Minimum Learning Limit

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 P11D5 Code

1. What are the common symptoms of OBDII code P11D5 NOx Sensor 2 Exceeded Minimum Learning Limit?

- Common symptoms include poor engine performance, decreased fuel efficiency, and the illumination of the Check Engine Light.

2. What are the possible causes of OBDII code P11D5 NOx Sensor 2 Exceeded Minimum Learning Limit?

- Possible causes may include a faulty NOx sensor, issues with the NOx sensor wiring, exhaust leaks, or a problem with the vehicle's engine control module.

3. How can I diagnose OBDII code P11D5 NOx Sensor 2 Exceeded Minimum Learning Limit?

- Diagnosing this code typically involves using an OBDII scanner to retrieve the code, inspecting the NOx sensor and its wiring, checking for exhaust leaks, and testing the functionality of the sensor.

4. Can I continue driving my vehicle with OBDII code P11D5 NOx Sensor 2 Exceeded Minimum Learning Limit?

- It is not recommended to continue driving your vehicle with this code as it can lead to further damage to the engine and emissions system. It is best to address the issue promptly.

5. How can I repair OBDII code P11D5 NOx Sensor 2 Exceeded Minimum Learning Limit?

- Repairing this code may involve replacing the NOx sensor, repairing any damaged wiring, fixing exhaust leaks, or reprogramming the engine control module.

6. Is it possible to reset OBDII code P11D5 NOx Sensor 2 Exceeded Minimum Learning Limit without repairing the issue?

- While clearing the code using an OBDII scanner may temporarily turn off the Check Engine Light, the underlying issue causing the code will persist until properly repaired.

7. Can a DIY enthusiast fix OBDII code P11D5 NOx Sensor 2 Exceeded Minimum Learning Limit?

- Depending on the individual's skill level and access to tools, some DIY enthusiasts may be able to diagnose and repair this code. However, it is recommended to seek professional help for accurate diagnosis and repair.

8. How long does it typically take to repair OBDII code P11D5 NOx Sensor 2 Exceeded Minimum Learning Limit?

- The repair time can vary depending on the exact cause of the code and the availability of parts. In general, it may take a few hours to a day to diagnose and repair this issue.

9. Are there any preventive maintenance tips to avoid OBDII code P11D5 NOx Sensor 2 Exceeded Minimum Learning Limit?

- Regularly servicing your vehicle, addressing any exhaust leaks promptly, and ensuring proper engine maintenance can help prevent issues that may trigger this OBDII code.

10. Will ignoring OBDII code P11D5 NOx Sensor 2 Exceeded Minimum Learning Limit cause further damage to my vehicle?

- Ignoring this code can potentially lead to decreased engine performance, reduced fuel efficiency, and further damage to the emissions system. It is recommended to address the issue as soon as possible.