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P22A9 2015 Chevrolet Silverado Code - NOx Sensor 2 Heater Feedback Circuit Low Voltage

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
P22A9 2015 Chevrolet Silverado indicates NOx Sensor 2 Heater Feedback Circuit Low Voltage.
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 190
How popular is this code, among other codes? Low
What is this?
Table of contents Created and updated by William Orellana on Mar 24, 2024
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Code P22A9 2015 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 P22A9 2015 Chevrolet Silverado - NOx Sensor 2 Heater Feedback Circuit Low Voltage - AutoCodes.com
P22A9 2015 Chevrolet Silverado Code - NOx Sensor 2 Heater Feedback Circuit Low Voltage
What does this mean?

What are the Possible Causes of the DTC P22A9 2015 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 P22A9 2015 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 P22A9 2015 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 P22A9 2015 Chevrolet Silverado code?

Need more information on how to fix the P22A9 2015 Chevrolet Silverado code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P22A9 2015 Chevrolet Silverado 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 P22A9 2015 Chevrolet Silverado Code

1. What are the common symptoms of OBDII code P22A9 in a 2015 Chevrolet Silverado?

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

2. What does the OBDII code P22A9 indicate in a 2015 Chevrolet Silverado?

- This code specifically refers to an issue with the NOx Sensor 2 Heater Feedback Circuit registering low voltage.

3. What are the possible causes of the NOx Sensor 2 Heater Feedback Circuit low voltage issue in a 2015 Chevrolet Silverado?

- Possible causes include a faulty NOx sensor, damaged wiring or connectors, a blown fuse, or a problem with the sensor's heating element.

4. How can I diagnose the NOx Sensor 2 Heater Feedback Circuit low voltage problem in my 2015 Chevrolet Silverado?

- Diagnosing this issue usually involves using an OBDII scanner to retrieve the fault code, inspecting the sensor and its connections for damage, and testing the sensor's voltage.

5. Can driving with OBDII code P22A9 in a 2015 Chevrolet Silverado cause further damage?

- Continuing to drive with this issue may potentially lead to increased emissions, reduced engine efficiency, and could cause damage to other components over time.

6. Are there any repair tips for fixing the NOx Sensor 2 Heater Feedback Circuit low voltage problem in a 2015 Chevrolet Silverado?

- Repair tips include checking and repairing any damaged wiring or connectors, replacing the NOx sensor if necessary, and ensuring the sensor's heating element is functioning correctly.

7. Is it safe to continue driving my 2015 Chevrolet Silverado with the check engine light on due to code P22A9?

- While the vehicle may still be operable, it is recommended to address the underlying issue promptly to prevent potential damage and ensure optimal engine performance.

8. How much does it typically cost to repair OBDII code P22A9 in a 2015 Chevrolet Silverado?

- The cost of repairing this issue can vary depending on the exact cause and whether professional diagnosis and labor are required. Costs may range from a few hundred to over a thousand dollars.

9. Can I reset the check engine light caused by code P22A9 in my 2015 Chevrolet Silverado without fixing the underlying issue?

- While you can clear the code and reset the check engine light temporarily, it is important to address the root cause to prevent ongoing problems and potential damage to your vehicle.

10. Will fixing the NOx Sensor 2 Heater Feedback Circuit low voltage problem improve the overall performance of my 2015 Chevrolet Silverado?

- Yes, resolving this issue can lead to improved engine performance, better fuel efficiency, and ensure your vehicle meets emission standards.

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