AutoCodes – Chevrolet – P22A9 2017 Chevrolet Silverado

P22A9 2017 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 2017 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 223

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 P22A9 2017 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 2017 Chevrolet Silverado - NOx Sensor 2 Heater Feedback Circuit Low Voltage - AutoCodes.com — P22A9 2017 Chevrolet Silverado Code - NOx Sensor 2 Heater Feedback Circuit Low Voltage

What does this mean?

What are the Possible Causes of the DTC P22A9 2017 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 2017 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 2017 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 2017 Chevrolet Silverado code?

Need more information on how to fix the P22A9 2017 Chevrolet Silverado code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P22A9 2017 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 2017 Chevrolet Silverado Code

1. What are the common symptoms of OBDII code P22A9 (NOx Sensor 2 Heater Feedback Circuit Low Voltage) in a 2017 Chevrolet Silverado?

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

2. What are the possible causes of OBDII code P22A9 in a 2017 Chevrolet Silverado?

Possible causes of this code could be a faulty NOx sensor, a malfunctioning heater circuit, wiring issues, or a problem with the vehicle's engine control module (ECM).

3. How does the NOx sensor 2 heater feedback circuit work in a 2017 Chevrolet Silverado?

The NOx sensor 2 heater feedback circuit is responsible for ensuring the NOx sensor operates within the correct temperature range to accurately measure the levels of nitrogen oxide in the vehicle's emissions.

4. How can I diagnose OBDII code P22A9 in my 2017 Chevrolet Silverado?

Diagnosing this code typically involves using an OBDII scanner to retrieve the fault code, inspecting the NOx sensor and its wiring for damage, and testing the heater circuit for proper voltage.

5. Can I still drive my 2017 Chevrolet Silverado with OBDII code P22A9 present?

It is not recommended to drive your vehicle with this code present, as it can lead to further damage and potential emissions issues. It is best to address the underlying problem as soon as possible.

6. Is it safe to continue driving my 2017 Chevrolet Silverado if the check engine light is on due to code P22A9?

While the vehicle may still be operable, it is advisable to address the issue promptly to prevent any potential long-term damage and ensure optimal engine performance and emissions control.

7. How much does it typically cost to repair OBDII code P22A9 in a 2017 Chevrolet Silverado?

The cost of repairing this code can vary depending on the exact cause of the issue. It is recommended to consult a professional mechanic for an accurate diagnosis and repair estimate.

8. Can a DIY enthusiast fix OBDII code P22A9 in a 2017 Chevrolet Silverado?

While some experienced DIY enthusiasts may be able to address this issue themselves by following repair guides and using the right tools, it is often best to seek assistance from a qualified mechanic for proper diagnosis and repair.

9. Are there any preventative maintenance tips to avoid OBDII code P22A9 in a 2017 Chevrolet Silverado?

Regularly servicing your vehicle, including checking the condition of sensors and wiring, can help prevent issues like code P22A9. Additionally, avoiding rough driving and ensuring timely repairs can contribute to maintaining optimal vehicle performance.

10. How long does it typically take to repair OBDII code P22A9 in a 2017 Chevrolet Silverado?

The repair time for this code can vary depending on the exact cause of the issue and the availability of parts. It is advisable to consult with a mechanic for a more accurate estimate of the repair duration.