AutoCodes – Chevrolet – P2BAC Chevrolet

P2BAC Chevrolet Code - NOx Exceedence - Deactivation of EGR

Quick Answer

The selective catalytic reduction system reduces oxides of nitrogen (NOx) emissions by injecting a metered amount of diesel exhaust fluid or reductant into the exhaust gas stream entering the diesel particulate filter (DPF). Common causes include Faulty NOx Sensors, NOx Sensors harness is open or shorted, NOx Sensors 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: P2BAC Chevrolet indicates NOx Exceedence - Deactivation of EGR.
Common causes: Common causes include Faulty NOx Sensors, NOx Sensors harness is open or shorted, NOx Sensors 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 1,733

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 Feb 17, 2019

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 P2BAC Chevrolet Description

The selective catalytic reduction system reduces oxides of nitrogen (NOx) emissions by injecting a metered amount of diesel exhaust fluid or reductant into the exhaust gas stream entering the diesel particulate filter (DPF). Within the selective catalytic reduction catalyst, the reductant reacts with the NOx to form nitrogen, carbon dioxide, and water vapor. Upstream and downstream NOx sensors provide the Engine Control Module (ECM) with engine-out and tailpipe-out NOx levels.
The ECM uses the 2 NOx sensors to control exhaust NOx levels. The NOx sensor measures the amount of NOx and oxygen in the exhaust system. The first NOx sensor is located at the outlet of the turbocharger and monitors the engine out NOx. The second NOx sensor is located in the DPF that monitors NOx levels exiting the DPF. The ECM varies the amount of reductant added by varying the reductant injector duty cycle in response to changes in engine exhaust out NOx levels.

OBDII Code P2BAC Chevrolet - NOx Exceedence - Deactivation of EGR - AutoCodes.com — P2BAC Chevrolet Code - NOx Exceedence - Deactivation of EGR

What does this mean?

What are the Possible Causes of the DTC P2BAC Chevrolet?

Faulty NOx Sensors
NOx Sensors harness is open or shorted
NOx Sensors circuit poor electrical connection
Fualty Diesel Particulate Filter (DPF)

How to Fix the DTC P2BAC Chevrolet?

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 P2BAC Chevrolet 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 P2BAC Chevrolet code?

Need more information on how to fix the P2BAC Chevrolet code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P2BAC Chevrolet code diagnosed by a professional: Find a repair shop in your area

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 P2BAC Chevrolet Code

What are common symptoms of OBDII code P2BAC in a Chevrolet related to NOx exceedence?

Symptoms may include decreased engine performance, rough idling, increased fuel consumption, and the illumination of the Check Engine Light.

What does the OBDII code P2BAC Chevrolet indicate about NOx exceedence and deactivation of EGR?

The code P2BAC typically indicates that the engine control module has detected excessive levels of nitrogen oxide (NOx) emissions due to the deactivation of the exhaust gas recirculation (EGR) system.

What are some possible causes of the P2BAC code in a Chevrolet?

Potential causes include a faulty EGR valve, clogged EGR passages, wiring issues in the EGR system, a malfunctioning NOx sensor, or a problem with the engine control module.

How can I diagnose the OBDII code P2BAC in a Chevrolet related to NOx exceedence?

Diagnosis usually involves using a scan tool to retrieve the code, performing a visual inspection of the EGR system components, testing the EGR valve and sensor, and checking for any exhaust leaks.

What are the repair options for resolving the P2BAC code in a Chevrolet?

Repairs may involve cleaning or replacing the EGR valve, clearing any blockages in the EGR passages, repairing or replacing damaged wiring, replacing the NOx sensor, or reprogramming the engine control module.

Is it safe to continue driving with the P2BAC code in a Chevrolet?

It is generally not recommended to drive with a persistent P2BAC code, as it can lead to increased emissions, reduced fuel efficiency, and potential damage to the engine components. It is advisable to address the issue promptly.

How can I prevent the OBDII code P2BAC from recurring in my Chevrolet?

Regular maintenance of the EGR system, using high-quality fuel, and driving with care to avoid harsh acceleration and deceleration can help prevent the recurrence of the P2BAC code related to NOx exceedence.

Can resetting the Check Engine Light resolve the P2BAC code in a Chevrolet?

While resetting the Check Engine Light may temporarily turn it off, it will not fix the underlying issue causing the P2BAC code. It is important to diagnose and repair the problem to prevent further emissions-related issues.