AutoCodes – Buick – P22A1 Buick

P22A1 Buick Code - NOx Sensor 2 Circuit High 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: P22A1 Buick indicates NOx Sensor 2 Circuit High 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 477

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 P22A1 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 P22A1 Buick - NOx Sensor 2 Circuit High Voltage - AutoCodes.com — P22A1 Buick Code - NOx Sensor 2 Circuit High Voltage

What does this mean?

What are the Possible Causes of the DTC P22A1 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 P22A1 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 P22A1 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 P22A1 Buick Code

1. What are the common symptoms of OBDII code P22A1 in a Buick related to NOx Sensor 2 Circuit High Voltage?

The common symptoms include the check engine light being illuminated, decreased fuel efficiency, and potentially rough engine performance.

2. What are the possible causes of the NOx Sensor 2 Circuit High Voltage code in a Buick?

Possible causes of this code include a faulty NOx sensor, issues with the wiring or connectors, exhaust system leaks, or problems with the engine control module.

3. How serious is the P22A1 code related to NOx Sensor 2 Circuit High Voltage in a Buick?

While the severity can vary, it is advisable to address this code promptly as it can lead to increased emissions, reduced engine efficiency, and potential damage to the catalytic converter.

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

Diagnosing this issue typically involves using an OBDII scanner to retrieve the fault code, inspecting the NOx sensor and its wiring for any visible damage, and conducting a thorough examination of the exhaust system.

5. Can I continue driving my Buick with the P22A1 code related to the NOx Sensor 2 Circuit High Voltage?

It is generally not recommended to continue driving with this fault code present, as it can potentially lead to further damage to the vehicle and may cause it to fail emissions tests.

6. How can I repair the NOx Sensor 2 Circuit High Voltage issue in my Buick?

Repairing this issue may involve replacing the NOx sensor, repairing any damaged wiring or connectors, addressing exhaust leaks, or resetting the engine control module after resolving the underlying problem.

7. What are some tips to prevent the recurrence of the P22A1 code in my Buick?

To prevent the recurrence of this fault code, it is essential to perform regular maintenance on your vehicle, address any issues promptly, and ensure proper functioning of all emissions-related components.

8. How much does it typically cost to repair the NOx Sensor 2 Circuit High Voltage problem in a Buick?

The cost of repairing this issue can vary depending on the exact cause of the problem, but it may range from a few hundred to a few thousand dollars, including parts and labor.

9. Can a DIY enthusiast fix the P22A1 code related to NOx Sensor 2 Circuit High Voltage in a Buick?

While some DIY enthusiasts may be able to address this issue themselves, it is recommended to have the problem diagnosed by a professional to ensure an accurate repair and prevent further complications.

10. Will resetting the check engine light resolve the NOx Sensor 2 Circuit High Voltage code in my Buick?

Resetting the check engine light may temporarily clear the code, but it will not fix the underlying issue causing the fault code to appear. It is crucial to diagnose and address the root cause of the problem for a lasting solution.