AutoCodes – Chevrolet – P22A1 Chevrolet

P22A1 Chevrolet 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 Chevrolet 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 5,315

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

What does this mean?

What are the Possible Causes of the DTC P22A1 Chevrolet?

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 Chevrolet?

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 Chevrolet 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 P22A1 Chevrolet code?

Need more information on how to fix the P22A1 Chevrolet code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P22A1 Chevrolet code diagnosed by a professional: Find a repair shop in your area

Information for Specific Chevrolet Models

P22A1 2014 Chevrolet Silverado — NOx Sensor 2 Circuit High Voltage
P22A1 2015 Chevrolet Silverado — NOx Sensor 2 Circuit High Voltage
P22A1 2016 Chevrolet Silverado — NOx Sensor 2 Circuit High Voltage
P22A1 2017 Chevrolet Silverado — NOx Sensor 2 Circuit High Voltage
P22A1 2018 Chevrolet Silverado — NOx Sensor 2 Circuit High Voltage

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 Chevrolet Code

1. What are the common symptoms of OBDII code P22A1 Chevrolet (NOx Sensor 2 Circuit High Voltage)?

Symptoms may include poor engine performance, decreased fuel efficiency, rough idling, and the illumination of the Check Engine Light.

2. What can cause the OBDII code P22A1 Chevrolet to trigger?

Possible causes include a faulty NOx sensor, wiring issues in the sensor circuit, a malfunctioning powertrain control module (PCM), or exhaust system leaks.

3. How do I diagnose the OBDII code P22A1 Chevrolet?

Diagnosis typically involves using an OBDII scanner to retrieve the code, performing a visual inspection of the sensor and its wiring, and conducting voltage and resistance tests to pinpoint the issue.

4. Can I still drive my vehicle with the OBDII code P22A1 Chevrolet active?

It is not recommended to continue driving with this code present, as it can lead to further damage to the engine and emissions system. Prompt diagnosis and repair are advised.

5. How do I repair the NOx Sensor 2 Circuit High Voltage issue?

Repair may involve replacing the faulty NOx sensor, repairing damaged wiring or connections, resetting the PCM, and clearing the trouble code.

6. Can I reset the OBDII code P22A1 Chevrolet myself?

You can attempt to clear the code using an OBDII scanner, but it is crucial to address the underlying issue causing the code before resetting it. If the problem persists, the code will likely reappear.

7. Is the NOx Sensor 2 Circuit High Voltage issue a common problem in Chevrolet vehicles?

While not extremely common, this issue can occur in Chevrolet vehicles equipped with NOx sensors, especially in models with high mileage or older vehicles.

8. Are there any preventive measures to avoid triggering the OBDII code P22A1 Chevrolet?

Regular maintenance, such as keeping up with engine tune-ups, monitoring sensor performance, and addressing any engine issues promptly, can help prevent this code from appearing.

9. Can a DIY enthusiast replace the NOx sensor to resolve the P22A1 Chevrolet code?

Replacing the NOx sensor can be a complex task requiring specialized tools and knowledge. It is recommended to consult a professional mechanic for proper diagnosis and repair.

10. Will ignoring the OBDII code P22A1 Chevrolet cause long-term damage to my vehicle?

Continuing to drive with this code unresolved can potentially lead to increased emissions, reduced engine efficiency, and possible damage to the catalytic converter or other engine components. Addressing the issue promptly is crucial.