AutoCodes – Chevrolet – P22A4 2016 Chevrolet Silverado

P22A4 2016 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 2016 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.

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Code Popularity 248

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

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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 P22A4 2016 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 2016 Chevrolet Silverado - NOx Sensor 2 Heater Control Circuit Low Voltage - AutoCodes.com — P22A4 2016 Chevrolet Silverado Code - NOx Sensor 2 Heater Control Circuit Low Voltage

What does this mean?

What are the Possible Causes of the DTC P22A4 2016 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 2016 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 2016 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 2016 Chevrolet Silverado code?

Need more information on how to fix the P22A4 2016 Chevrolet Silverado code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P22A4 2016 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 2016 Chevrolet Silverado Code

What does the OBDII code P22A4 mean for a 2016 Chevrolet Silverado?

The P22A4 code indicates a problem with the NOx Sensor 2 Heater Control Circuit, specifically detecting a low voltage condition.

What are the common symptoms of code P22A4 in a 2016 Chevrolet Silverado?

Symptoms may include the check engine light turning on, reduced fuel efficiency, poor engine performance, or the vehicle entering limp mode.

What causes the P22A4 code to appear?

Common causes include a faulty NOx sensor, damaged wiring or connectors in the heater control circuit, or an issue with the engine control module (ECM).

Can I still drive my 2016 Chevrolet Silverado with the P22A4 code?

While the truck may still be drivable, prolonged operation with this code can lead to decreased fuel efficiency and potential damage to the emissions system.

How do you diagnose the P22A4 code?

Diagnosis involves scanning for codes, visually inspecting wiring and connectors, testing the NOx sensor heater resistance, and checking for proper voltage in the control circuit.

What repairs can fix the P22A4 code?

Repairs may include replacing the NOx sensor, repairing or replacing damaged wiring or connectors, or addressing issues with the ECM.

How much does it cost to fix the P22A4 code?

The repair cost varies but typically ranges from $300 to $800, depending on whether the NOx sensor or wiring needs replacement.

Can a software update resolve the P22A4 code?

In some cases, an ECM software update may resolve the issue if it is related to incorrect programming or calibration.

How can I prevent the P22A4 code from recurring?

Regular maintenance, ensuring proper fuel quality, and checking wiring and connectors for damage can help prevent this code from returning.

Is the P22A4 code covered under warranty for a 2016 Chevrolet Silverado?

It may be covered under the emissions warranty if the vehicle is within the mileage and time limits specified by Chevrolet. Check with your dealership for confirmation.