AutoCodes – GMC – P22A5 GMC

P22A5 GMC Code - NOx Sensor 2 Heater Control Circuit High 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: P22A5 GMC indicates NOx Sensor 2 Heater Control Circuit High 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 632

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 P22A5 GMC 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 P22A5 GMC - NOx Sensor 2 Heater Control Circuit High Voltage - AutoCodes.com — P22A5 GMC Code - NOx Sensor 2 Heater Control Circuit High Voltage

What does this mean?

What are the Possible Causes of the DTC P22A5 GMC?

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 P22A5 GMC?

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 P22A5 GMC 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 P22A5 GMC code?

Need more information on how to fix the P22A5 GMC code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P22A5 GMC code diagnosed by a professional: Find a repair shop in your area

Information for Specific GMC Models

P22A5 2014 GMC Sierra — NOx Sensor 2 Heater Control Circuit High Voltage
P22A5 2015 GMC Sierra — NOx Sensor 2 Heater Control Circuit High Voltage
P22A5 2016 GMC Sierra — NOx Sensor 2 Heater Control Circuit High Voltage
P22A5 2017 GMC Sierra — NOx Sensor 2 Heater Control Circuit High Voltage
P22A5 2018 GMC Sierra — NOx Sensor 2 Heater Control Circuit High 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 P22A5 GMC Code

1. What are the common symptoms of OBDII code P22A5 in a GMC vehicle?

- Common symptoms include the Check Engine Light coming on, reduced engine performance, and potentially increased fuel consumption.

2. What does the OBDII code P22A5 GMC indicate?

- The code P22A5 indicates a high voltage condition in the control circuit of the NOx Sensor 2 Heater in a GMC vehicle.

3. What are the possible causes of the NOx Sensor 2 Heater Control Circuit High Voltage error code?

- Possible causes include a faulty NOx sensor, wiring issues, a defective heater element, or a problem with the vehicle's engine control module.

4. How can I diagnose the cause of the P22A5 code in my GMC vehicle?

- Diagnosing the issue may involve inspecting the wiring for damage, testing the NOx sensor and its heater element, and checking the engine control module for faults using a diagnostic scanner.

5. Can I continue driving my GMC vehicle with the P22A5 code present?

- It is not recommended to drive the vehicle with the P22A5 code illuminated, as it may lead to decreased fuel efficiency and potential engine performance issues.

6. How can I repair the NOx Sensor 2 Heater Control Circuit High Voltage issue in my GMC vehicle?

- Repairing the issue may involve replacing the faulty NOx sensor, repairing damaged wiring, or addressing any issues with the heater element. It's advisable to consult a professional mechanic for proper diagnosis and repair.

7. Are there any simple DIY fixes for the P22A5 code in a GMC vehicle?

- Simple fixes may include checking and tightening any loose connections in the sensor circuit or clearing the code with a diagnostic scanner to see if it returns.

8. Can weather conditions affect the NOx Sensor 2 Heater Control Circuit in a GMC vehicle?

- Extreme weather conditions, such as very low temperatures, can potentially affect the performance of the NOx sensor heater and trigger the P22A5 code.

9. How long does it typically take to repair the NOx Sensor 2 Heater Control Circuit High Voltage issue?

- The repair time can vary depending on the exact cause of the issue, but it may take anywhere from a few hours to a full day for a professional mechanic to diagnose and repair the problem.

10. Is the NOx Sensor 2 Heater Control Circuit High Voltage error a common issue in GMC vehicles?

- While it may not be as common as some other OBDII codes, the P22A5 error can occur in GMC vehicles, particularly in models equipped with NOx sensors for emissions control.