AutoCodes – GMC – P22A9 2014 GMC Sierra

P22A9 2014 GMC Sierra Code - NOx Sensor 2 Heater Feedback Circuit Low Voltage

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: P22A9 2014 GMC Sierra indicates NOx Sensor 2 Heater Feedback Circuit Low Voltage.
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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 139

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
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code P22A9 2014 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 P22A9 2014 GMC Sierra - NOx Sensor 2 Heater Feedback Circuit Low Voltage - AutoCodes.com — P22A9 2014 GMC Sierra Code - NOx Sensor 2 Heater Feedback Circuit Low Voltage

What does this mean?

What are the Possible Causes of the DTC P22A9 2014 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 P22A9 2014 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 P22A9 2014 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 P22A9 2014 GMC Sierra code?

Need more information on how to fix the P22A9 2014 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P22A9 2014 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 P22A9 2014 GMC Sierra Code

1. What are the common symptoms of OBDII code P22A9 in a 2014 GMC Sierra related to the NOx Sensor 2 Heater Feedback Circuit Low Voltage?

The common symptoms include the Check Engine Light illuminating, reduced engine performance, and potential issues passing emissions tests.

2. What are the possible causes of OBDII code P22A9 in a 2014 GMC Sierra indicating NOx Sensor 2 Heater Feedback Circuit Low Voltage?

Possible causes may include a faulty NOx sensor, damaged wiring or connectors in the sensor circuit, or a malfunctioning heater element within the sensor.

3. How can I diagnose the OBDII code P22A9 in my 2014 GMC Sierra associated with the NOx Sensor 2 Heater Feedback Circuit Low Voltage?

Diagnosis typically involves using an OBDII scanner to read the code, inspecting the NOx sensor and its wiring for visible damage, and testing the sensor's resistance and heater circuit.

4. Can I continue driving my 2014 GMC Sierra with the OBDII code P22A9 related to NOx Sensor 2 Heater Feedback Circuit Low Voltage?

While the vehicle may still be operable, it's advisable to address the issue promptly to prevent potential damage to the emissions system and ensure optimal engine performance.

5. How do I repair OBDII code P22A9 in a 2014 GMC Sierra linked to NOx Sensor 2 Heater Feedback Circuit Low Voltage?

Repair typically involves replacing the faulty NOx sensor, repairing or replacing damaged wiring or connectors, or addressing any issues with the heater element within the sensor.

6. Are there any tips to prevent OBDII code P22A9 from recurring in my 2014 GMC Sierra after repair?

To prevent code recurrence, ensure proper installation of the new sensor, conduct regular maintenance checks on the sensor and its wiring, and address any underlying issues that may have led to the fault.

7. Can a DIY enthusiast with basic automotive knowledge fix OBDII code P22A9 in a 2014 GMC Sierra caused by NOx Sensor 2 Heater Feedback Circuit Low Voltage?

While some DIYers may be able to replace the NOx sensor or address basic wiring issues, it's recommended to consult a professional mechanic for accurate diagnosis and repair of complex electrical faults.

8. How much can I expect to pay for repairing OBDII code P22A9 in a 2014 GMC Sierra due to NOx Sensor 2 Heater Feedback Circuit Low Voltage?

The repair costs can vary depending on the extent of the issue, parts needed, and labor rates. It's advisable to obtain quotes from different automotive shops for an accurate estimate.

9. Is it possible for a temporary glitch to trigger OBDII code P22A9 in a 2014 GMC Sierra related to NOx Sensor 2 Heater Feedback Circuit Low Voltage?

Temporary glitches can sometimes trigger the code, but if the issue persists or recurs, it's essential to investigate and address the underlying cause to prevent potential long-term damage.

10. How critical is it to address OBDII code P22A9 in a 2014 GMC Sierra indicating NOx Sensor 2 Heater Feedback Circuit Low Voltage promptly?

It's important to address the code promptly to maintain proper emissions control, prevent potential engine performance issues, and ensure compliance with emissions regulations.