AutoCodes – GMC – P22A3 2018 GMC Sierra

P22A3 2018 GMC Sierra 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 2018 GMC Sierra 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 196

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 P22A3 2018 GMC Sierra 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 2018 GMC Sierra - NOx Sensor 2 Heater Control Circuit - AutoCodes.com — P22A3 2018 GMC Sierra Code - NOx Sensor 2 Heater Control Circuit

What does this mean?

What are the Possible Causes of the DTC P22A3 2018 GMC Sierra?

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 2018 GMC Sierra?

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 2018 GMC Sierra 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 2018 GMC Sierra code?

Need more information on how to fix the P22A3 2018 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the Code?

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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 2018 GMC Sierra Code

1. What are the common symptoms of OBDII code P22A3 in a 2018 GMC Sierra related to NOx Sensor 2 Heater Control Circuit?

The common symptoms include the Check Engine Light coming on, reduced engine performance, increased fuel consumption, and potential exhaust emission issues.

2. What are the possible causes of OBDII code P22A3 on a 2018 GMC Sierra indicating a NOx Sensor 2 Heater Control Circuit problem?

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

3. How can I diagnose the NOx Sensor 2 Heater Control Circuit issue triggering code P22A3 in my 2018 GMC Sierra?

You can diagnose the problem by performing a thorough inspection of the NOx sensor and its wiring, checking the heater circuit for continuity, and using a diagnostic scanner to read and interpret the trouble codes stored in the ECM.

4. What are the repair options for addressing OBDII code P22A3 on a 2018 GMC Sierra related to NOx Sensor 2 Heater Control Circuit?

Repair options may include replacing the faulty NOx sensor, repairing or replacing damaged wiring or connectors, fixing issues with the heater control circuit, or reprogramming the ECM if necessary.

5. Can I continue driving my 2018 GMC Sierra with OBDII code P22A3 indicating a NOx Sensor 2 Heater Control Circuit problem?

It is not recommended to continue driving the vehicle with this issue, as it can lead to increased emissions, reduced fuel efficiency, and potential damage to other engine components over time.

6. How much does it typically cost to repair OBDII code P22A3 on a 2018 GMC Sierra related to NOx Sensor 2 Heater Control Circuit?

The cost of repair can vary depending on the specific cause of the issue, but it may range from a few hundred to over a thousand dollars, including parts and labor.

7. Are there any preventive maintenance tips to avoid encountering OBDII code P22A3 in a 2018 GMC Sierra due to NOx Sensor 2 Heater Control Circuit problems?

Regularly inspecting and maintaining the NOx sensor, checking the wiring for any signs of wear or damage, and addressing any related engine issues promptly can help prevent this code from appearing.

8. Can a DIY enthusiast with automotive knowledge repair OBDII code P22A3 on a 2018 GMC Sierra related to NOx Sensor 2 Heater Control Circuit?

While some aspects of the repair may be within reach for skilled DIY enthusiasts, diagnosing and fixing issues related to NOx sensors and heater circuits often require specialized tools and expertise best handled by professional mechanics.

9. Will resetting the Check Engine Light make OBDII code P22A3 disappear temporarily in a 2018 GMC Sierra with NOx Sensor 2 Heater Control Circuit concerns?

Resetting the Check Engine Light without addressing the underlying issue will only temporarily clear the code, as it is likely to reappear once the ECM detects the problem during subsequent driving cycles.

10. Is it necessary to replace both NOx sensors if OBDII code P22A3 is triggered in a 2018 GMC Sierra indicating a NOx Sensor 2 Heater Control Circuit fault?

It is not always necessary to replace both NOx sensors, as the specific fault code P22A3 points to an issue with NOx Sensor 2. However, it is recommended to inspect both sensors and replace any that show signs of failure to prevent future problems.