AutoCodes – GMC – P22F9 GMC

P22F9 GMC Code - NOx Sensor 1 Performance Slow Response Low To High

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: P22F9 GMC indicates NOx Sensor 1 Performance Slow Response Low To High.
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 1,946

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 29, 2024

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P22F9 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 P22F9 GMC - NOx Sensor 1 Performance Slow Response Low To High - AutoCodes.com — P22F9 GMC Code - NOx Sensor 1 Performance Slow Response Low To High

What does this mean?

What are the Possible Causes of the DTC P22F9 GMC?

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 P22F9 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 P22F9 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 P22F9 GMC code?

Need more information on how to fix the P22F9 GMC code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P22F9 GMC code diagnosed by a professional: Find a repair shop in your area

Information for Specific GMC Models

P22F9 2014 GMC Sierra — NOx Sensor 1 Performance Slow Response Low To High
P22F9 2015 GMC Sierra — NOx Sensor 1 Performance Slow Response Low To High
P22F9 2016 GMC Sierra — NOx Sensor 1 Performance Slow Response Low To High
P22F9 2017 GMC Sierra — NOx Sensor 1 Performance Slow Response Low To High
P22F9 2018 GMC Sierra — NOx Sensor 1 Performance Slow Response Low To High

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 P22F9 GMC Code

What does the OBDII code P22F9 mean for my GMC vehicle?

The OBDII code P22F9 indicates a problem with the performance of the NOx (Nitrogen Oxide) sensor 1, specifically a slow response from low to high levels.

What are the common symptoms associated with the P22F9 code?

Common symptoms include poor engine performance, increased emissions, a decrease in fuel efficiency, and the illumination of the check engine light.

What could cause the P22F9 code to trigger?

Causes may include a faulty NOx sensor, wiring issues, exhaust leaks, or problems with the engine control module (ECM).

How can I diagnose the P22F9 code?

To diagnose the P22F9 code, you can use an OBDII scanner to confirm the code, inspect the NOx sensor and wiring for damage, and check for exhaust leaks.

Is it safe to drive with the P22F9 code?

While it may be safe to drive short distances, itâ€™s advisable to address the issue promptly as it can lead to further engine problems and increased emissions.

What are some common repair tips for the P22F9 code?

Common repairs include replacing the NOx sensor, repairing or replacing damaged wiring, and ensuring there are no exhaust leaks affecting sensor performance.

Will clearing the P22F9 code fix the issue?

Clearing the code may temporarily turn off the check engine light, but it won't fix the underlying problem. The code is likely to return if the issue isn't resolved.

How much does it typically cost to repair the P22F9 code?

Repair costs can vary widely depending on the specific issue, but replacing a NOx sensor may range from $100 to $300, including parts and labor.

Can I fix the P22F9 code myself, or should I take it to a mechanic?

If you have experience with automotive repairs, you may be able to replace the NOx sensor or repair wiring yourself. However, if you're unsure, itâ€™s best to consult a professional mechanic.