AutoCodes.com
Login with Google
AutoCodes – GMC – P22B6 GMC

P22B6 GMC Code - HO2S Pump Current Trim Circuit Low 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
P22B6 GMC indicates HO2S Pump Current Trim Circuit Low 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.
Save to My Repairs My Repairs
AI answers can be wrong. Verify repairs with testing. Open full chat
Code Popularity 506
How popular is this code, among other codes? Low
What is this?
Table of contents Created and updated by William Orellana on Sep 30, 2022
💬 Need more help? Ask Coddy for instant answers — it's free!

Code P22B6 GMC Description

The oxygen content of the exhaust is measured via the nitrogen oxide (NOx) sensors. 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 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 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 P22B6 GMC - HO2S Pump Current Trim Circuit Low Voltage Sensor 2 - AutoCodes.com
P22B6 GMC Code - HO2S Pump Current Trim Circuit Low Voltage Sensor 2
What does this mean?

What are the Possible Causes of the DTC P22B6 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 P22B6 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 P22B6 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 P22B6 GMC code?

Need more information on how to fix the P22B6 GMC code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P22B6 GMC code diagnosed by a professional: Find a repair shop in your area

Information for Specific GMC Models

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 P22B6 GMC Code

1. What does the OBDII code P22B6 mean for a GMC vehicle?

P22B6 indicates a low voltage issue in the HO2S (Heated Oxygen Sensor) Pump Current Trim Circuit for Sensor 2, which monitors and adjusts the air-fuel ratio.

2. What are the common symptoms of the P22B6 code in a GMC?

Symptoms may include an illuminated check engine light, poor fuel economy, rough idling, reduced engine performance, or failed emissions tests.

3. What causes the P22B6 code to appear on a GMC?

Possible causes include a faulty oxygen sensor, damaged wiring or connectors, a malfunctioning powertrain control module (PCM), or a blown fuse in the O2 sensor circuit.

4. Can I drive my GMC with the P22B6 code active?

While the vehicle may still be drivable, continuing to drive with this code can lead to increased fuel consumption, performance issues, or potential damage to the catalytic converter.

5. How is the P22B6 code diagnosed in a GMC?

A mechanic will use a scan tool to confirm the code, inspect the wiring and connectors for damage, test the oxygen sensor, and check the circuit voltage.

6. What repairs are typically needed to fix the P22B6 code in a GMC?

Repairs may include replacing a failed oxygen sensor, repairing damaged wiring, cleaning or replacing connectors, or reprogramming or replacing the PCM if needed.

7. How much does it cost to repair the P22B6 code on a GMC?

Repair costs vary but typically range from $150 to $400, depending on whether the oxygen sensor or wiring needs replacement and labor rates.

8. Can a faulty oxygen sensor itself cause the P22B6 code?

Yes, a malfunctioning oxygen sensor is one of the most common causes of this code.

9. How can I prevent the P22B6 code from reoccurring on my GMC?

Regular maintenance, timely replacement of oxygen sensors, and inspecting wiring for wear or damage can help prevent this code from recurring.

10. Does the P22B6 code affect emissions on a GMC vehicle?

Yes, this code can negatively impact emissions by causing an improper air-fuel mixture, potentially leading to failed emissions tests.

Discuss the causes and fixes for P22B6 GMC OBDII Code

Submit a New Comment

Code P22B6 GMC comments

No comments found for this page.

AutoCodes App

Fix Your Car Smarter

Try the New AutoCodes App!

Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.

AutoCodes App on Google Play