AutoCodes – GMC – P22FA 2018 GMC Sierra

P22FA 2018 GMC Sierra Code - NOx Sensor 1 Performance Slow Response High To Low

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, Nitrogen Oxides Sensor harness is open or shorted, Nitrogen Oxides Sensor 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: P22FA 2018 GMC Sierra indicates NOx Sensor 1 Performance Slow Response High To Low.
Common causes: Common causes include Faulty Nitrogen Oxides (NOx) Sensor, Nitrogen Oxides Sensor harness is open or shorted, Nitrogen Oxides Sensor 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 143

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 P22FA 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 P22FA 2018 GMC Sierra - NOx Sensor 1 Performance Slow Response High To Low - AutoCodes.com — P22FA 2018 GMC Sierra Code - NOx Sensor 1 Performance Slow Response High To Low

What does this mean?

What are the Possible Causes of the DTC P22FA 2018 GMC Sierra?

Faulty Nitrogen Oxides (NOx) Sensor
Nitrogen Oxides Sensor harness is open or shorted
Nitrogen Oxides Sensor circuit poor electrical connection

How to Fix the DTC P22FA 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 P22FA 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 P22FA 2018 GMC Sierra code?

Need more information on how to fix the P22FA 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 P22FA 2018 GMC Sierra Code

1. What are the common symptoms of OBDII code P22FA in a 2018 GMC Sierra?

- Common symptoms include poor engine performance, reduced fuel efficiency, and illuminated Check Engine Light.

2. What causes the OBDII code P22FA related to NOx Sensor 1 in a 2018 GMC Sierra?

- The code is typically triggered by a slow response from the NOx Sensor 1, indicating a problem with the sensor or its related components.

3. How serious is the P22FA OBDII code in a 2018 GMC Sierra?

- While the code may not cause immediate drivability issues, it can lead to increased emissions and potential long-term damage if left unresolved.

4. Can driving with the P22FA code on a 2018 GMC Sierra cause further damage?

- Continuing to drive with the code may result in increased emissions, reduced fuel efficiency, and potential damage to the vehicle's emissions system over time.

5. How can I diagnose the NOx Sensor 1 Performance Slow Response issue in my 2018 GMC Sierra?

- Diagnosis typically involves using an OBDII scanner to retrieve the specific fault code and then inspecting the NOx Sensor 1 and its connections for any issues.

6. What are some common repair tips for fixing the P22FA code on a 2018 GMC Sierra?

- Repair tips may include cleaning or replacing the NOx Sensor 1, checking and repairing any damaged wiring or connections, and resetting the fault code with an OBDII scanner.

7. Is it possible to reset the P22FA code in a 2018 GMC Sierra without fixing the underlying issue?

- While you can clear the code temporarily, it will likely reappear if the root cause of the NOx Sensor 1 performance issue is not addressed.

8. Can a DIY enthusiast fix the NOx Sensor 1 Performance Slow Response problem on a 2018 GMC Sierra?

- Depending on their skill level and access to tools, DIY enthusiasts may be able to replace the NOx Sensor 1 or check for basic wiring issues, but more complex diagnostics may require professional help.

9. Are there any recalls or technical service bulletins related to the P22FA code in a 2018 GMC Sierra?

- It's recommended to check with authorized GMC dealerships or online databases for any recalls or technical service bulletins related to the NOx Sensor 1 performance issue in your specific vehicle.

10. How can I prevent the OBDII code P22FA from reoccurring in my 2018 GMC Sierra?

- Regular maintenance, including checking and cleaning the NOx Sensor 1, ensuring proper fuel quality, and addressing any engine performance issues promptly, can help prevent the code from reoccurring.