AutoCodes – GMC – P22A3 GMC

P22A3 GMC 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 GMC 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 499

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

What does this mean?

What are the Possible Causes of the DTC P22A3 GMC?

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 GMC?

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 GMC 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 GMC code?

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

Need Help with the Code?

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

Information for Specific GMC Models

P22A3 2014 GMC Sierra — NOx Sensor 2 Heater Control Circuit
P22A3 2015 GMC Sierra — NOx Sensor 2 Heater Control Circuit
P22A3 2016 GMC Sierra — NOx Sensor 2 Heater Control Circuit
P22A3 2017 GMC Sierra — NOx Sensor 2 Heater Control Circuit
P22A3 2018 GMC Sierra — 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 GMC Code

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

- Common symptoms include decreased fuel efficiency, engine misfires, and the illumination of the check engine light.

2. What are the possible causes of the P22A3 GMC OBDII code?

- The code may be triggered by a faulty NOx sensor, damaged wiring or connectors, or issues with the heating element in the sensor.

3. How can I diagnose the P22A3 GMC code related to NOx Sensor 2 Heater Control Circuit?

- A thorough inspection of the NOx sensor, wiring, and connectors is recommended using a diagnostic scanner to read the code and monitor sensor data.

4. Can I still drive my vehicle with a P22A3 OBDII code?

- It is not recommended to drive with a P22A3 code as it can lead to decreased engine performance and potential damage to the emissions control system.

5. How can I repair a P22A3 GMC code related to NOx Sensor 2 Heater Control Circuit?

- Repair options may include replacing the NOx sensor, repairing damaged wiring or connectors, or addressing issues with the sensor's heating element.

6. Is it possible to reset the P22A3 GMC OBDII code without addressing the underlying issue?

- While clearing the code may temporarily turn off the check engine light, it is essential to diagnose and repair the root cause to prevent further issues.

7. Are there any preventive maintenance tips to avoid the P22A3 OBDII code?

- Regularly servicing the vehicle, checking for damaged wiring, and monitoring the NOx sensor's performance can help prevent the recurrence of this code.

8. Can a DIY enthusiast address the P22A3 GMC code on their own?

- Depending on the individual's skill level and access to tools, some DIY enthusiasts may be able to diagnose and repair the issue related to the NOx Sensor 2 Heater Control Circuit.

9. How long does it typically take to repair a P22A3 GMC OBDII code?

- The repair time can vary based on the exact cause of the code and the complexity of the repair, but it may take anywhere from a few hours to a full day.

10. Will ignoring the P22A3 GMC code cause further damage to the vehicle?

- Ignoring the P22A3 code can lead to decreased engine performance, increased emissions, and potential damage to other components in the emissions control system over time.