AutoCodes – Buick – P22A0 Buick

P22A0 Buick Code - NOx Sensor 2 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: P22A0 Buick indicates NOx Sensor 2 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.

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Code Popularity 459

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 P22A0 Buick 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 P22A0 Buick - NOx Sensor 2 Circuit Low Voltage - AutoCodes.com — P22A0 Buick Code - NOx Sensor 2 Circuit Low Voltage

What does this mean?

What are the Possible Causes of the DTC P22A0 Buick?

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 P22A0 Buick?

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 P22A0 Buick 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.

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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 P22A0 Buick Code

1. What are the common symptoms of OBDII code P22A0 in a Buick related to NOx Sensor 2 Circuit Low Voltage?

The common symptoms include reduced engine performance, decreased fuel efficiency, and the illumination of the check engine light.

2. What are the possible causes of OBDII code P22A0 in a Buick indicating NOx Sensor 2 Circuit Low Voltage?

Possible causes include a faulty NOx sensor, wiring issues, connector problems, a malfunctioning engine control module, or a failed catalytic converter.

3. How can I diagnose the NOx Sensor 2 Circuit Low Voltage issue in my Buick?

You can diagnose the problem by using an OBDII scanner to read the fault code, visually inspecting the sensor and its wiring for any visible damage, and performing electrical tests to check for continuity and voltage.

4. Can I continue driving my Buick with OBDII code P22A0 related to NOx Sensor 2 Circuit Low Voltage?

It is not recommended to drive your vehicle with this code as it can lead to increased emissions, potential damage to the catalytic converter, and further engine issues.

5. How do I repair OBDII code P22A0 in my Buick indicating NOx Sensor 2 Circuit Low Voltage?

Repair options include replacing the NOx sensor, fixing any wiring or connector issues, resetting the engine control module, or replacing the catalytic converter if necessary.

6. Will resetting the check engine light resolve the OBDII code P22A0 related to NOx Sensor 2 Circuit Low Voltage in my Buick?

Resetting the check engine light may temporarily turn it off, but it will not fix the underlying issue causing the code. It is important to diagnose and repair the problem to prevent further damage.

7. How much does it cost to repair OBDII code P22A0 NOx Sensor 2 Circuit Low Voltage in a Buick?

The cost of repair can vary depending on the cause of the issue, but it typically ranges from $200 to $600, including parts and labor.

8. Can a DIY enthusiast fix OBDII code P22A0 related to NOx Sensor 2 Circuit Low Voltage in a Buick?

While some simple tasks like checking the wiring connections can be done by a DIY enthusiast, diagnosing and repairing the NOx sensor or complex wiring issues may require professional help.

9. How often does the NOx sensor need to be replaced in a Buick experiencing OBDII code P22A0?

The NOx sensor typically lasts around 100,000 miles, but it can vary depending on driving conditions and maintenance. It is recommended to follow the manufacturer's guidelines for sensor replacement.

10. Will OBDII code P22A0 related to NOx Sensor 2 Circuit Low Voltage cause my Buick to fail an emissions test?

Yes, having this code can cause your vehicle to fail an emissions test as it indicates issues with the NOx sensor, which is crucial for emissions control. It is important to address the problem before undergoing an emissions test.