AutoCodes – Chevrolet – P22A8 2014 Chevrolet Silverado

P22A8 2014 Chevrolet Silverado Code - NOx Sensor 2 Heater Feedback 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: P22A8 2014 Chevrolet Silverado indicates NOx Sensor 2 Heater Feedback 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 219

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 P22A8 2014 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 P22A8 2014 Chevrolet Silverado - NOx Sensor 2 Heater Feedback Circuit Low Voltage - AutoCodes.com — P22A8 2014 Chevrolet Silverado Code - NOx Sensor 2 Heater Feedback Circuit Low Voltage

What does this mean?

What are the Possible Causes of the DTC P22A8 2014 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 P22A8 2014 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 P22A8 2014 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 P22A8 2014 Chevrolet Silverado code?

Need more information on how to fix the P22A8 2014 Chevrolet Silverado code? Get Access to Factory Service Manuals

Need Help with the Code?

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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 P22A8 2014 Chevrolet Silverado Code

1. What does the OBDII code P22A8 mean on a 2014 Chevrolet Silverado?

P22A8 indicates a problem with the NOx Sensor 2 Heater Feedback Circuit, specifically reporting low voltage.

2. What are the common symptoms of code P22A8?

Symptoms may include an illuminated check engine light, reduced fuel efficiency, decreased engine performance, or the vehicle entering limp mode.

3. What causes the P22A8 code to appear?

The code is typically caused by a faulty NOx sensor, issues with the sensor's heater circuit, damaged wiring or connectors, or a malfunctioning Engine Control Module (ECM).

4. Can I drive my 2014 Chevrolet Silverado with a P22A8 code?

While the truck may still be drivable, operating it with this code can lead to increased emissions, reduced performance, and potential damage to the catalytic converter.

5. How do you fix a P22A8 code on a Chevrolet Silverado?

Repairs may involve replacing the faulty NOx sensor, repairing damaged wiring or connectors, or reprogramming/updating the ECM.

6. How can I test the NOx Sensor 2 Heater Feedback Circuit for low voltage?

Use a multimeter to check the voltage and resistance in the NOx sensor circuit and inspect for any damaged or corroded wiring.

7. Where is NOx Sensor 2 located on a 2014 Chevrolet Silverado?

NOx Sensor 2 is typically located downstream, after the catalytic converter, in the exhaust system.

8. What tools are needed to diagnose and fix a P22A8 code?

Youâ€™ll need an OBDII scanner, a multimeter, and basic automotive tools to inspect and replace components as needed.

9. How much does it cost to repair the P22A8 code?

The cost can vary, but replacing the NOx sensor typically ranges from $300 to $700, including parts and labor.

10. Can a software update resolve the P22A8 code?

In some cases, a software update for the ECM may resolve the issue, but this should be done after verifying the sensor and circuit are functioning properly.