AutoCodes – GMC – P22A7 2018 GMC Sierra

P22A7 2018 GMC Sierra Code - NOx Sensor 2 Heater Feedback Performance

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: P22A7 2018 GMC Sierra indicates NOx Sensor 2 Heater Feedback Performance.
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 299

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 P22A7 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 P22A7 2018 GMC Sierra - NOx Sensor 2 Heater Feedback Performance - AutoCodes.com — P22A7 2018 GMC Sierra Code - NOx Sensor 2 Heater Feedback Performance

What does this mean?

What are the Possible Causes of the DTC P22A7 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 P22A7 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 P22A7 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 P22A7 2018 GMC Sierra code?

Need more information on how to fix the P22A7 2018 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P22A7 2018 GMC Sierra 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 P22A7 2018 GMC Sierra Code

1. What are the common symptoms of OBDII code P22A7 in a 2018 GMC Sierra related to NOx Sensor 2 Heater Feedback Performance?

The common symptoms include illuminated check engine light, reduced engine performance, and potential failure to pass emissions tests.

2. What are the possible causes of OBDII code P22A7 in a 2018 GMC Sierra?

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

3. How can I diagnose the OBDII code P22A7 in my 2018 GMC Sierra?

Diagnosis involves using a scan tool to retrieve the specific fault code, inspecting the NOx sensor and its connections, checking the wiring for any damage, and testing the NOx sensor heater circuit.

4. Can I continue driving my 2018 GMC Sierra with OBDII code P22A7 present?

It is not recommended to continue driving with this fault code present, as it can lead to reduced engine performance and potential long-term damage if left unresolved.

5. How can I repair OBDII code P22A7 in my 2018 GMC Sierra related to NOx Sensor 2 Heater Feedback Performance?

Repair may involve replacing the NOx sensor, repairing or replacing damaged wiring, fixing any issues with the NOx sensor heater circuit, or reprogramming the ECM.

6. Is it possible to reset the OBDII code P22A7 in a 2018 GMC Sierra without fixing the underlying issue?

While you can clear the fault code with a scan tool, the check engine light will likely reappear if the underlying problem causing the code is not addressed.

7. Are there any DIY tips for troubleshooting OBDII code P22A7 in a 2018 GMC Sierra?

DIY tips include checking the sensor connections and wiring for any visible damage, ensuring proper sensor operation, and consulting the vehicle's service manual for specific diagnostic procedures.

8. Can a faulty NOx sensor cause other issues in a 2018 GMC Sierra besides triggering OBDII code P22A7?

Yes, a faulty NOx sensor can potentially affect the vehicle's emissions performance, fuel efficiency, and overall engine operation if not functioning correctly.

9. How much does it typically cost to repair OBDII code P22A7 in a 2018 GMC Sierra at a dealership or auto repair shop?

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

10. Are there any recalls or technical service bulletins related to OBDII code P22A7 in a 2018 GMC Sierra?

It's recommended to check with a GMC dealership or the manufacturer's website to see if there are any recalls or technical service bulletins addressing this specific OBDII code in the 2018 GMC Sierra.