AutoCodes – Chevrolet – P22A0 Chevrolet

P22A0 Chevrolet 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 Chevrolet 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 5,668

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
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P22A0 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 P22A0 Chevrolet - NOx Sensor 2 Circuit Low Voltage - AutoCodes.com — P22A0 Chevrolet Code - NOx Sensor 2 Circuit Low Voltage

What does this mean?

What are the Possible Causes of the DTC P22A0 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 P22A0 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 does this mean?

Code Tech Notes

There is a Factory Service Bulletin for the following Chevrolet models:
2010 Chevrolet Express
2011 Chevrolet Express
2011 Chevrolet Silverado
Chevrolet Factory Service Bulletin OBDII Code P22A0

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P22A0 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 P22A0 Chevrolet code?

Need more information on how to fix the P22A0 Chevrolet code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P22A0 Chevrolet code diagnosed by a professional: Find a repair shop in your area

Information for Specific Chevrolet Models

P22A0 2014 Chevrolet Silverado — NOx Sensor 2 Circuit Low Voltage
P22A0 2015 Chevrolet Silverado — NOx Sensor 2 Circuit Low Voltage
P22A0 2016 Chevrolet Silverado — NOx Sensor 2 Circuit Low Voltage
P22A0 2017 Chevrolet Silverado — NOx Sensor 2 Circuit Low Voltage
P22A0 2018 Chevrolet Silverado — NOx Sensor 2 Circuit Low 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 P22A0 Chevrolet Code

1. What are common symptoms of OBDII code P22A0 Chevrolet (NOx Sensor 2 Circuit Low Voltage)?

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

2. What are the possible causes of OBDII code P22A0 Chevrolet?

- Possible causes include a faulty NOx sensor, damaged wiring or connectors, issues with the engine control module (ECM), or exhaust system problems.

3. How can I diagnose OBDII code P22A0 Chevrolet?

- Diagnosis typically involves using a diagnostic scanner to retrieve the trouble code and then inspecting the NOx sensor, related wiring, and ECM for any visible damage or issues.

4. Can I still drive my vehicle with OBDII code P22A0 Chevrolet?

- It is generally not recommended to drive with this code present, as it can lead to further engine or emissions system damage. It's best to address the issue promptly.

5. How can I repair OBDII code P22A0 Chevrolet?

- Repair may involve replacing the NOx sensor, repairing or replacing damaged wiring or connectors, resetting the ECM, or addressing any underlying exhaust system problems.

6. Are there any DIY tips for fixing OBDII code P22A0 Chevrolet?

- DIY tips may include checking the sensor and wiring for visible damage, cleaning any connections, and resetting the ECM to see if the code clears.

7. Is it important to fix OBDII code P22A0 Chevrolet immediately?

- Yes, it is important to address this code promptly to prevent potential damage to the engine or emissions system and ensure proper vehicle performance.

8. Can weather conditions affect OBDII code P22A0 Chevrolet?

- Extreme weather conditions, such as extreme heat or cold, can potentially impact the NOx sensor's performance and trigger this code.

9. How much does it cost to repair OBDII code P22A0 Chevrolet?

- The cost of repair can vary depending on the underlying issue, but it may involve parts and labor costs ranging from $200 to $500 or more at a repair shop.

10. How long does it take to repair OBDII code P22A0 Chevrolet?

- Repair time can vary based on the specific issue and the expertise of the technician, but it typically takes a few hours to a full day to diagnose and fix the problem.