AutoCodes – Generic – P220B

P220B Code - NOx Sensor 2 Supply Voltage Circuit

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: P220B indicates NOx Sensor 2 Supply Voltage Circuit.
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 7,908

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 Jul 27, 2021

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P220B 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 when the sensor supply voltage is less than 10.8 V.

OBDII Code P220B - NOx Sensor 2 Supply Voltage Circuit - AutoCodes.com — P220B Code - NOx Sensor 2 Supply Voltage Circuit

What does this mean?

What are the Possible Causes of the DTC P220B?

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 P220B?

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 P220B 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 P220B code?

Need more information on how to fix the P220B code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P220B code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

P220B Buick — NOx Sensor 2 Supply Voltage Circuit
P220B Cadillac — NOx Sensor 2 Supply Voltage Circuit
P220B Chevrolet — NOx Sensor 2 Supply Voltage Circuit
P220B GMC — NOx Sensor 2 Supply Voltage Circuit

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 P220B Code

1. What are the common symptoms of OBDII code P220B (NOx Sensor 2 Supply Voltage Circuit)?

The common symptoms include poor engine performance, rough idling, decreased fuel efficiency, and potential illumination of the Check Engine Light.

2. What are the possible causes of OBDII code P220B?

The code P220B can be triggered by issues such as a faulty NOx sensor, damaged wiring or connectors in the NOx sensor circuit, a failing powertrain control module (PCM), or a malfunctioning NOx sensor heater.

3. How can I diagnose the OBDII code P220B?

Diagnosing code P220B typically involves using a diagnostic scanner to retrieve the trouble codes, inspecting the NOx sensor and its wiring for any visible damage, and testing the sensor's functionality using a multimeter.

4. Can I continue driving with OBDII code P220B present?

It is not recommended to continue driving with code P220B present, as it can lead to further damage to the engine and emissions control system. It is best to address the issue promptly.

5. How can I repair OBDII code P220B?

Repairing code P220B may involve replacing the NOx sensor, repairing or replacing damaged wiring or connectors, resetting the fault codes with a diagnostic tool, and ensuring that the issue causing the code is resolved.

6. Are there any DIY tips for fixing OBDII code P220B?

While some basic troubleshooting steps can be done by DIY enthusiasts, it is recommended to seek professional help when dealing with NOx sensor-related issues due to the complexity of the system.

7. How much does it cost to repair OBDII code P220B?

The cost of repairing code P220B can vary depending on the underlying issue, the labor rates in your area, and the cost of parts needed for the repair. It is advisable to get a few quotes from different mechanics.

8. Can a faulty NOx sensor cause other issues in the vehicle?

Yes, a faulty NOx sensor can lead to poor engine performance, increased emissions, and potential damage to the catalytic converter if not addressed promptly.

9. How long does it take to repair OBDII code P220B?

The repair time for code P220B can vary depending on the exact cause of the issue and the availability of parts. In some cases, it can be resolved within a few hours, while more complex issues may take longer to diagnose and repair.

10. Is it possible to prevent OBDII code P220B from recurring in the future?

Regular maintenance of the vehicle, including checking the NOx sensor and its wiring for any signs of wear or damage, can help prevent code P220B from recurring.