AutoCodes – GMC – P22A7 GMC

P22A7 GMC 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 GMC 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 1,331

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

What does this mean?

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

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

Need Help with the Code?

Get the P22A7 GMC code diagnosed by a professional: Find a repair shop in your area

Information for Specific GMC Models

P22A7 2014 GMC Sierra — NOx Sensor 2 Heater Feedback Performance
P22A7 2015 GMC Sierra — NOx Sensor 2 Heater Feedback Performance
P22A7 2016 GMC Sierra — NOx Sensor 2 Heater Feedback Performance
P22A7 2017 GMC Sierra — NOx Sensor 2 Heater Feedback Performance
P22A7 2018 GMC Sierra — NOx Sensor 2 Heater Feedback Performance

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 GMC Code

1. What are the common symptoms of OBDII code P22A7 GMC (NOx Sensor 2 Heater Feedback Performance)?

- Common symptoms include decreased fuel efficiency, rough idling, and potentially a check engine light on the dashboard.

2. What are the possible causes of OBDII code P22A7 GMC (NOx Sensor 2 Heater Feedback Performance)?

- Possible causes include a faulty NOx sensor, issues with the sensor's heater circuit, wiring problems, or a damaged sensor connector.

3. How can I diagnose OBDII code P22A7 GMC (NOx Sensor 2 Heater Feedback Performance)?

- Diagnosing this code typically involves using an OBDII scanner to read the code, inspecting the NOx sensor and its connections, and testing the heater circuit for proper functionality.

4. Can I continue driving with OBDII code P22A7 GMC (NOx Sensor 2 Heater Feedback Performance) present?

- It is not recommended to continue driving with this code active, as it can lead to increased emissions, reduced engine performance, and potential damage to other components.

5. How serious is OBDII code P22A7 GMC (NOx Sensor 2 Heater Feedback Performance)?

- While this code may not cause immediate engine failure, ignoring it can lead to higher emissions output and decreased fuel efficiency over time.

6. Is it possible to repair OBDII code P22A7 GMC (NOx Sensor 2 Heater Feedback Performance) at home?

- Depending on your mechanical skills and access to tools, it may be possible to address this issue at home by replacing the faulty NOx sensor or repairing the heater circuit.

7. How much does it cost to fix OBDII code P22A7 GMC (NOx Sensor 2 Heater Feedback Performance)?

- The cost of fixing this code can vary depending on the extent of the issue, but it typically ranges from $200 to $500, including parts and labor.

8. Can a faulty NOx sensor cause other problems in the vehicle?

- Yes, a faulty NOx sensor can lead to increased emissions, reduced engine performance, and potential damage to the catalytic converter if left unresolved.

9. Are there any maintenance tips to prevent OBDII code P22A7 GMC (NOx Sensor 2 Heater Feedback Performance) from occurring?

- Regularly inspecting and maintaining the NOx sensor, as well as ensuring proper wiring connections, can help prevent this code from appearing.

10. How long does it take to repair OBDII code P22A7 GMC (NOx Sensor 2 Heater Feedback Performance)?

- The repair time can vary depending on the exact cause of the issue, but most mechanics can address this code within a few hours to a day.

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