AutoCodes – GMC – P22B7 GMC

P22B7 GMC Code - HO2S Pump Current Trim Circuit High Voltage Sensor 2

Quick Answer

The oxygen content of the exhaust is measured via the Nitrogen Oxide (NOx) sensors. Common causes include Faulty Nitrogen Oxide (NOx) Sensor 2, Nitrogen Oxide Sensor 2 harness is open or shorted, Nitrogen Oxide 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: P22B7 GMC indicates HO2S Pump Current Trim Circuit High Voltage Sensor 2.
Common causes: Common causes include Faulty Nitrogen Oxide (NOx) Sensor 2, Nitrogen Oxide Sensor 2 harness is open or shorted, Nitrogen Oxide 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 422

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 Sep 30, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P22B7 GMC Description

The oxygen content of the exhaust is measured via the Nitrogen Oxide (NOx) sensors. The Nitrogen Oxide (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 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 when the NOx sensor module detects a fault in the NOx sensor circuitry or a performance fault in the NOx sensor.

OBDII Code P22B7 GMC - HO2S Pump Current Trim Circuit High Voltage Sensor 2 - AutoCodes.com — P22B7 GMC Code - HO2S Pump Current Trim Circuit High Voltage Sensor 2

What does this mean?

What are the Possible Causes of the DTC P22B7 GMC?

Faulty Nitrogen Oxide (NOx) Sensor 2
Nitrogen Oxide Sensor 2 harness is open or shorted
Nitrogen Oxide Sensor 2 circuit poor electrical connection

How to Fix the DTC P22B7 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 P22B7 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 P22B7 GMC code?

Need more information on how to fix the P22B7 GMC code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P22B7 GMC code diagnosed by a professional: Find a repair shop in your area

Information for Specific GMC Models

P22B7 2014 GMC Sierra — HO2S Pump Current Trim Circuit High Voltage Sensor 2
P22B7 2015 GMC Sierra — HO2S Pump Current Trim Circuit High Voltage Sensor 2
P22B7 2016 GMC Sierra — HO2S Pump Current Trim Circuit High Voltage Sensor 2
P22B7 2017 GMC Sierra — HO2S Pump Current Trim Circuit High Voltage Sensor 2
P22B7 2018 GMC Sierra — HO2S Pump Current Trim Circuit High Voltage Sensor 2

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 P22B7 GMC Code

1. What does the OBDII code P22B7 GMC indicate?

- The P22B7 GMC code indicates a problem with the HO2S (Heated Oxygen Sensor) Pump Current Trim Circuit for Sensor 2, specifically pointing to a high voltage issue in the circuit.

2. What are common symptoms of code P22B7 on a GMC vehicle?

- Symptoms may include a check engine light, poor fuel economy, rough engine idle, and potentially higher emissions.

3. What could cause the P22B7 code to appear in a GMC?

- Possible causes include faulty oxygen sensors, wiring issues (such as shorts or corrosion in the connections), or problems with the engine control module (ECM).

4. How can I diagnose the P22B7 code in my GMC vehicle?

- Diagnosis should start with a visual inspection of the wiring and connectors for damage or corrosion. Use an OBDII scanner to check for additional codes and freeze frame data. Testing the oxygen sensor and its circuit with a multimeter can also be helpful.

5. Is it safe to drive a GMC with the P22B7 code active?

- While you can drive the vehicle, it's not advisable to do so for an extended period. Driving with this issue can lead to reduced engine performance and increased fuel consumption, and potentially more serious engine issues.

6. What steps should be taken to fix the P22B7 code on a GMC?

- Repairing this code may involve replacing the faulty oxygen sensor, repairing or replacing damaged wiring or connectors, or in some cases, updating or replacing the ECM.

7. How urgent is it to address the P22B7 code in a GMC?

- It is moderately urgent. While the vehicle can still operate, the condition can worsen over time, leading to increased emissions, reduced fuel efficiency, and potential damage to other components.

8. Could a P22B7 code result in a failed emissions test?

- Yes, since this code indicates an issue with the oxygen sensor, which is crucial for controlling exhaust emissions, it can lead to increased emissions that may cause the vehicle to fail emissions testing.

9. What tools are required to diagnose and repair a P22B7 code?

- Tools needed include an OBDII scanner, a digital multimeter for electrical testing, and basic hand tools for accessing and replacing components.