AutoCodes – Chevrolet – P22A3 Chevrolet

P22A3 Chevrolet 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 Chevrolet 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 2,885

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

What does this mean?

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

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

Need Help with the Code?

Get the P22A3 Chevrolet code diagnosed by a professional: Find a repair shop in your area

Information for Specific Chevrolet Models

P22A3 2014 Chevrolet Silverado — NOx Sensor 2 Heater Control Circuit
P22A3 2015 Chevrolet Silverado — NOx Sensor 2 Heater Control Circuit
P22A3 2016 Chevrolet Silverado — NOx Sensor 2 Heater Control Circuit
P22A3 2017 Chevrolet Silverado — NOx Sensor 2 Heater Control Circuit
P22A3 2018 Chevrolet Silverado — NOx Sensor 2 Heater Control Circuit

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 Chevrolet Code

What does the OBDII code P22A3 mean for a Chevrolet vehicle?

The OBDII code P22A3 indicates a problem with the NOx (Nitrogen Oxide) Sensor 2 heater control circuit, which affects the sensor's ability to operate correctly.

What symptoms might I experience if my vehicle has the P22A3 code?

Common symptoms include poor fuel economy, increased emissions, a rough running engine, and the check engine light being illuminated.

What are the potential causes of the P22A3 code?

Potential causes include a faulty NOx sensor 2, issues with the NOx sensor heater circuit, damaged wiring or connectors, or a problem with the engine control module (ECM).

Can I drive my vehicle with the P22A3 code?

While it is possible to drive with this code, it is not recommended as it may lead to poor performance and increased emissions. It's best to address the issue as soon as possible.

How can I diagnose the P22A3 code?

To diagnose the P22A3 code, use an OBDII scanner to confirm the code, inspect the NOx sensor 2 and its wiring for damage, check the heater circuit for continuity, and test the sensorâ€™s functionality.

What repairs are commonly needed to fix the P22A3 code?

Repairs may include replacing the NOx sensor 2, repairing or replacing damaged wiring or connectors, or checking and resolving issues with the ECM if it is not functioning correctly.

Will clearing the P22A3 code fix the issue?

Clearing the code may temporarily turn off the check engine light, but it will not fix the underlying issue. The code will likely return if the problem is not resolved.

How much does it typically cost to repair the P22A3 code?

Repair costs can vary widely depending on the specific issue, but replacing a NOx sensor generally ranges from $200 to $600, including parts and labor.

Is there a way to prevent the P22A3 code from occurring?

Regular maintenance, including timely oil changes and ensuring the emission control system is functioning properly, can help prevent issues related to the NOx sensor and related codes.