AutoCodes – Chevrolet – P22A4 2015 Chevrolet Silverado

P22A4 2015 Chevrolet Silverado Code - NOx Sensor 2 Heater Control 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: P22A4 2015 Chevrolet Silverado indicates NOx Sensor 2 Heater Control 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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 207

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
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code P22A4 2015 Chevrolet Silverado 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 P22A4 2015 Chevrolet Silverado - NOx Sensor 2 Heater Control Circuit Low Voltage - AutoCodes.com — P22A4 2015 Chevrolet Silverado Code - NOx Sensor 2 Heater Control Circuit Low Voltage

What does this mean?

What are the Possible Causes of the DTC P22A4 2015 Chevrolet Silverado?

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 P22A4 2015 Chevrolet Silverado?

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 P22A4 2015 Chevrolet Silverado 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 P22A4 2015 Chevrolet Silverado code?

Need more information on how to fix the P22A4 2015 Chevrolet Silverado code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P22A4 2015 Chevrolet Silverado code diagnosed by a professional: Find a repair shop in your area

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 P22A4 2015 Chevrolet Silverado Code

1. What are the common symptoms of OBDII code P22A4 in a 2015 Chevrolet Silverado related to NOx Sensor 2 Heater Control Circuit Low Voltage?

The common symptoms include the Check Engine Light coming on, decreased fuel efficiency, and potential issues passing emissions tests.

2. What are the possible causes of the NOx Sensor 2 Heater Control Circuit Low Voltage code (P22A4) in a 2015 Chevrolet Silverado?

Possible causes can include a faulty NOx sensor, damaged wiring or connectors, a blown fuse, or issues with the vehicle's electrical system.

3. How can I diagnose the NOx Sensor 2 Heater Control Circuit Low Voltage issue (P22A4) in my 2015 Chevrolet Silverado?

Diagnosis typically involves using an OBDII scanner to retrieve the specific fault code, inspecting the sensor and related components for damage, and testing the wiring and connections for continuity.

4. Can I continue driving my 2015 Chevrolet Silverado with the P22A4 NOx Sensor 2 Heater Control Circuit Low Voltage code?

It is generally not recommended to continue driving with this code present, as it can lead to decreased fuel efficiency and potential long-term damage to the vehicle's emissions system.

5. How can I repair the NOx Sensor 2 Heater Control Circuit Low Voltage issue (P22A4) in my 2015 Chevrolet Silverado?

Repair options may include replacing the NOx sensor, repairing or replacing damaged wiring or connectors, checking and replacing fuses if necessary, and resetting the fault code with an OBDII scanner.

6. Will resetting the Check Engine Light clear the P22A4 NOx Sensor 2 Heater Control Circuit Low Voltage code in my 2015 Chevrolet Silverado?

Resetting the Check Engine Light may temporarily clear the code, but if the underlying issue causing the fault code is not addressed, the code is likely to reappear.

7. How much does it typically cost to fix the P22A4 NOx Sensor 2 Heater Control Circuit Low Voltage code in a 2015 Chevrolet Silverado?

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

8. Can a DIY enthusiast fix the NOx Sensor 2 Heater Control Circuit Low Voltage issue (P22A4) in a 2015 Chevrolet Silverado?

While some simple repairs like checking and replacing fuses or connectors may be DIY-friendly, diagnosing and fixing more complex issues with the NOx sensor or wiring may require professional expertise and specialized tools.

9. How often does the P22A4 NOx Sensor 2 Heater Control Circuit Low Voltage code occur in a 2015 Chevrolet Silverado?

The occurrence of this specific code can vary depending on factors like driving conditions, maintenance, and the vehicle's overall health, but it is not considered a common issue in these vehicles.

10. What are the potential long-term effects of ignoring the P22A4 NOx Sensor 2 Heater Control Circuit Low Voltage code in a 2015 Chevrolet Silverado?

Ignoring this fault code can lead to increased emissions, decreased fuel efficiency, and potential damage to other components of the emissions system over time. It is best to address the issue promptly to avoid further problems.