AutoCodes – GMC – P22A6 GMC

P22A6 GMC Code - NOx Sensor 2 Heater Feedback Circuit

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: P22A6 GMC indicates NOx Sensor 2 Heater Feedback Circuit.
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 374

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 P22A6 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 P22A6 GMC - NOx Sensor 2 Heater Feedback Circuit - AutoCodes.com — P22A6 GMC Code - NOx Sensor 2 Heater Feedback Circuit

What does this mean?

What are the Possible Causes of the DTC P22A6 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 P22A6 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 P22A6 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 P22A6 GMC code?

Need more information on how to fix the P22A6 GMC code? Get Access to Factory Service Manuals

Need Help with the Code?

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Information for Specific GMC Models

P22A6 2014 GMC Sierra — NOx Sensor 2 Heater Feedback Circuit
P22A6 2015 GMC Sierra — NOx Sensor 2 Heater Feedback Circuit
P22A6 2016 GMC Sierra — NOx Sensor 2 Heater Feedback Circuit
P22A6 2017 GMC Sierra — NOx Sensor 2 Heater Feedback Circuit
P22A6 2018 GMC Sierra — NOx Sensor 2 Heater Feedback Circuit

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 P22A6 GMC Code

1. What are the common symptoms of OBDII code P22A6 related to NOx Sensor 2 Heater Feedback Circuit?

- Common symptoms include reduced engine performance, increased fuel consumption, and the illumination of the check engine light.

2. What are the possible causes of OBDII code P22A6 GMC?

- The code P22A6 GMC typically indicates a malfunction in the NOx Sensor 2 Heater Feedback Circuit, which can be caused by issues such as a faulty sensor, damaged wiring, or a failed heater element.

3. How can I diagnose the NOx Sensor 2 Heater Feedback Circuit issue causing code P22A6?

- To diagnose the problem, use an OBDII scanner to retrieve the specific trouble code. Then, perform a visual inspection of the sensor and its wiring for any visible damage. Testing the sensor's resistance and checking for power and ground signals can help pinpoint the issue.

4. Can I continue driving with OBDII code P22A6 GMC active?

- It is not recommended to continue driving with the code P22A6 active, as it can lead to poor engine performance and potentially cause further damage to the vehicle's emissions system.

5. How can I repair OBDII code P22A6 related to the NOx Sensor 2 Heater Feedback Circuit?

- Repairing the issue may involve replacing the faulty NOx sensor, repairing damaged wiring, or replacing the heater element. It's recommended to consult a professional mechanic for a proper diagnosis and repair.

6. Is it possible to reset the OBDII code P22A6 GMC without fixing the underlying issue?

- While you can clear the code temporarily using an OBDII scanner, the check engine light is likely to reappear if the root cause of the problem is not addressed.

7. Are there any tips to prevent OBDII code P22A6 from occurring in the future?

- Regularly maintaining your vehicle, including inspecting and replacing sensors as needed, can help prevent issues like code P22A6 related to the NOx Sensor 2 Heater Feedback Circuit.

8. Can a DIY enthusiast repair OBDII code P22A6 GMC on their own?

- Depending on their skill level, a DIY enthusiast may be able to diagnose and repair the issue causing code P22A6. However, complex repairs involving sensor replacement or wiring repairs are best left to professional mechanics.

9. How long does it typically take to repair OBDII code P22A6?

- The repair time for OBDII code P22A6 related to the NOx Sensor 2 Heater Feedback Circuit can vary based on the extent of the issue and the availability of parts. It may take a few hours to a full day for the repair to be completed.

10. Will fixing OBDII code P22A6 GMC improve my vehicle's performance and fuel efficiency?

- Yes, resolving the issue causing code P22A6 can help improve engine performance and fuel efficiency by ensuring proper operation of the emissions control system.