AutoCodes – Generic – P22A6

P22A6 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 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 2,982

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

What does this mean?

What are the Possible Causes of the DTC P22A6?

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?

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 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 code?

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Information for Specific Makes

P22A6 Buick — NOx Sensor 2 Heater Feedback Circuit
P22A6 Cadillac — NOx Sensor 2 Heater Feedback Circuit
P22A6 Chevrolet — NOx Sensor 2 Heater Feedback Circuit
P22A6 GMC — 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 Code

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

- Common symptoms include poor engine performance, decreased fuel efficiency, and the illumination of the Check Engine light.

2. What usually causes OBDII code P22A6 to trigger in relation to the NOx Sensor 2 Heater Feedback Circuit?

- The code is usually triggered by a malfunction in the NOx Sensor 2's heater feedback circuit, which may be caused by wiring issues, a faulty sensor, or a defective heater element.

3. How can I diagnose the issue related to OBDII code P22A6 for the NOx Sensor 2 Heater Feedback Circuit?

- Diagnosis typically involves using an OBDII scanner to read the fault code, inspecting the sensor and its wiring for any visible damage, and testing the sensor's resistance to determine if it is functioning properly.

4. Are there any simple repair tips for addressing OBDII code P22A6 associated with the NOx Sensor 2 Heater Feedback Circuit?

- Simple repair tips include checking and repairing any damaged wiring, replacing the NOx Sensor 2 if it is found to be faulty, and ensuring the heater element is receiving the proper voltage.

5. Can driving with OBDII code P22A6 related to the NOx Sensor 2 Heater Feedback Circuit cause further damage to the vehicle?

- Continuing to drive with this code may lead to increased emissions, potential damage to the catalytic converter, and reduced engine efficiency over time.

6. How urgent is it to address OBDII code P22A6 for the NOx Sensor 2 Heater Feedback Circuit?

- It is important to address this code promptly to prevent potential damage to the vehicle's emissions system and ensure optimal engine performance and fuel efficiency.

7. Is it possible to reset the Check Engine light after repairing OBDII code P22A6 linked to the NOx Sensor 2 Heater Feedback Circuit?

- Yes, the Check Engine light can be reset using an OBDII scanner after the issue causing the code has been repaired and cleared.

8. Are there any specific maintenance practices to prevent OBDII code P22A6 for the NOx Sensor 2 Heater Feedback Circuit?

- Regularly inspecting and maintaining the NOx sensors, ensuring proper wiring connections, and addressing any issues promptly can help prevent this code from occurring.

9. How much can I expect to pay for repairing OBDII code P22A6 related to the NOx Sensor 2 Heater Feedback Circuit?

- Repair costs can vary depending on the extent of the issue, but they typically range from $200 to $500, including parts and labor.

10. Can I fix OBDII code P22A6 for the NOx Sensor 2 Heater Feedback Circuit myself, or should I seek professional help?

- While some simple repairs like checking wiring connections can be done by DIY enthusiasts, diagnosing and replacing the NOx Sensor 2 or its heater element may require professional help for accurate and efficient resolution.