AutoCodes – Chevrolet – P22A4 2018 Chevrolet Silverado

P22A4 2018 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 2018 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 179

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 2018 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 2018 Chevrolet Silverado - NOx Sensor 2 Heater Control Circuit Low Voltage - AutoCodes.com — P22A4 2018 Chevrolet Silverado Code - NOx Sensor 2 Heater Control Circuit Low Voltage

What does this mean?

What are the Possible Causes of the DTC P22A4 2018 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 2018 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 2018 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 2018 Chevrolet Silverado code?

Need more information on how to fix the P22A4 2018 Chevrolet Silverado code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P22A4 2018 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 2018 Chevrolet Silverado Code

1. What are common symptoms of OBDII code P22A4 in a 2018 Chevrolet Silverado related to NOx Sensor 2 Heater Control Circuit Low Voltage?

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

2. What are the potential causes of OBDII code P22A4 in a 2018 Chevrolet Silverado indicating an issue with NOx Sensor 2 Heater Control Circuit Low Voltage?

- Possible causes include a faulty NOx sensor, damaged wiring or connectors, a blown fuse, or a malfunctioning heater control circuit.

3. How can I diagnose the issue behind OBDII code P22A4 in my 2018 Chevrolet Silverado that points to NOx Sensor 2 Heater Control Circuit Low Voltage?

- A thorough diagnosis involves checking the NOx sensor and its connections, inspecting the wiring for any damage, testing the heater circuit, and verifying the integrity of related fuses.

4. Can driving with OBDII code P22A4 in a 2018 Chevrolet Silverado related to NOx Sensor 2 Heater Control Circuit Low Voltage cause further damage?

- Continuing to drive with this code may lead to increased emissions, reduced engine efficiency, and potential long-term damage to emissions control components.

5. How can I repair OBDII code P22A4 in my 2018 Chevrolet Silverado associated with NOx Sensor 2 Heater Control Circuit Low Voltage?

- Repair typically involves replacing the faulty NOx sensor, repairing or replacing damaged wiring or connectors, checking and replacing blown fuses, and ensuring the heater control circuit functions properly.

6. Is it possible to reset OBDII code P22A4 in a 2018 Chevrolet Silverado related to NOx Sensor 2 Heater Control Circuit Low Voltage without fixing the underlying issue?

- While you can clear the code using an OBDII scanner, it is crucial to address the root cause to prevent the issue from recurring and potentially causing further problems.

7. Are there any DIY tips for addressing OBDII code P22A4 in a 2018 Chevrolet Silverado indicating an issue with NOx Sensor 2 Heater Control Circuit Low Voltage?

- DIY tips may include checking and cleaning sensor connectors, inspecting wiring for visible damage, and ensuring all relevant fuses are intact before seeking professional help if needed.

8. How long does it typically take to repair OBDII code P22A4 in a 2018 Chevrolet Silverado related to NOx Sensor 2 Heater Control Circuit Low Voltage?

- The repair time can vary based on the exact cause of the issue, but it may take anywhere from 1 to 3 hours for a professional technician to diagnose and fix the problem.

9. Can extreme weather conditions impact the occurrence of OBDII code P22A4 in a 2018 Chevrolet Silverado due to NOx Sensor 2 Heater Control Circuit Low Voltage?

- Yes, extreme cold or heat can sometimes affect sensor performance and the heater control circuit, potentially leading to the triggering of this code in your vehicle.

10. Is it necessary to visit a dealership for repairs related to OBDII code P22A4 in a 2018 Chevrolet Silverado linked to NOx Sensor 2 Heater Control Circuit Low Voltage?

- While a dealership can provide specialized expertise, independent auto repair shops with experience in diagnostics and emissions systems can also effectively diagnose and repair this issue in your vehicle.