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P22A3 2017 Chevrolet Silverado Code - NOx Sensor 2 Heater Control Circuit

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: P22A3 2017 Chevrolet Silverado indicates NOx Sensor 2 Heater Control Circuit.
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 398

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 P22A3 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 P22A3 2017 Chevrolet Silverado - NOx Sensor 2 Heater Control Circuit - AutoCodes.com — P22A3 2017 Chevrolet Silverado Code - NOx Sensor 2 Heater Control Circuit

What does this mean?

What are the Possible Causes of the DTC P22A3 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 P22A3 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 P22A3 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 P22A3 2017 Chevrolet Silverado code?

Need more information on how to fix the P22A3 2017 Chevrolet Silverado code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P22A3 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 P22A3 2017 Chevrolet Silverado Code

1. What does OBDII code P22A3 mean on a 2017 Chevrolet Silverado?

P22A3 indicates an issue with the NOx Sensor 2 Heater Control Circuit, typically related to the downstream NOx sensor used in the vehicle's emissions system.

2. What are the common symptoms of code P22A3 in a 2017 Chevrolet Silverado?

Symptoms may include the check engine light turning on, reduced fuel efficiency, increased emissions, or the engine entering limp mode.

3. What causes the P22A3 code to appear?

Common causes include a faulty NOx sensor, damaged sensor wiring or connectors, a malfunctioning heater element, or issues with the vehicleâ€™s PCM (Powertrain Control Module).

4. Can I drive my 2017 Chevrolet Silverado with a P22A3 code?

While the vehicle may still be drivable, ignoring this code can lead to increased emissions, reduced performance, and potential long-term damage to the emissions system.

5. How do I diagnose the P22A3 code on my Silverado?

Start by checking the NOx sensor wiring and connectors for damage or corrosion, then use a scan tool to confirm the sensorâ€™s heater circuit functionality.

6. How do I fix the P22A3 code in a 2017 Chevrolet Silverado?

Repairs may include replacing the NOx sensor, repairing damaged wiring or connectors, or reprogramming/resetting the PCM if itâ€™s causing the issue.

7. What is the purpose of the NOx Sensor 2 Heater?

The heater ensures the NOx sensor reaches its optimal operating temperature quickly, improving its accuracy in monitoring nitrogen oxide emissions.

8. How much does it cost to repair the P22A3 code?

Repair costs vary but typically range from $300 to $800, depending on whether the NOx sensor or wiring needs replacement.

9. Will clearing the P22A3 code fix the issue permanently?

Clearing the code without addressing the underlying problem will only temporarily turn off the check engine light. The issue will reoccur until repaired.

10. Can a faulty NOx sensor damage other parts of my Silverado?

Yes, a malfunctioning NOx sensor can lead to improper emissions control, potentially causing damage to the catalytic converter or other emission system components over time.