AutoCodes – Chevrolet – P119B Chevrolet

P119B Chevrolet Code - NOx Sensor 1 Signal Circuit Low 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, Nitrogen Oxides Sensor harness is open or shorted, Nitrogen Oxides Sensor 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: P119B Chevrolet indicates NOx Sensor 1 Signal Circuit Low Voltage.
Common causes: Common causes include Faulty Nitrogen Oxides (NOx) Sensor, Nitrogen Oxides Sensor harness is open or shorted, Nitrogen Oxides Sensor 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 507

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 Mar 29, 2024

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P119B Chevrolet 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 P119B Chevrolet - NOx Sensor 1 Signal Circuit Low Voltage - AutoCodes.com — P119B Chevrolet Code - NOx Sensor 1 Signal Circuit Low Voltage

What does this mean?

What are the Possible Causes of the DTC P119B Chevrolet?

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

How to Fix the DTC P119B 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 P119B 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 P119B Chevrolet code?

Need more information on how to fix the P119B Chevrolet code? Get Access to Factory Service Manuals

Need Help with the Code?

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Information for Specific Chevrolet Models

P119B 2014 Chevrolet Silverado — NOx Sensor 1 Signal Circuit Low Voltage
P119B 2015 Chevrolet Silverado — NOx Sensor 1 Signal Circuit Low Voltage
P119B 2016 Chevrolet Silverado — NOx Sensor 1 Signal Circuit Low Voltage
P119B 2017 Chevrolet Silverado — NOx Sensor 1 Signal Circuit Low Voltage
P119B 2018 Chevrolet Silverado — NOx Sensor 1 Signal Circuit Low 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 P119B Chevrolet Code

1. What are common symptoms of OBDII code P119B in a Chevrolet related to the NOx Sensor 1 Signal Circuit Low Voltage?

- Common symptoms include reduced engine performance, decreased fuel efficiency, and potential illumination of the check engine light.

2. What are the possible causes of the NOx Sensor 1 Signal Circuit Low Voltage code P119B in a Chevrolet?

- The code may be triggered by issues such as a faulty NOx sensor, wiring or connector problems, a damaged sensor harness, or a malfunction in the engine control module.

3. How can I diagnose the cause of OBDII code P119B related to the NOx sensor in my Chevrolet?

- Diagnosis typically involves conducting a visual inspection of sensor connections and wiring, testing the sensor for proper voltage output, and using a diagnostic scan tool to retrieve specific trouble codes.

4. Can I continue driving my Chevrolet with the P119B code related to the NOx sensor?

- While the vehicle may still operate, it is advisable to address the issue promptly to prevent potential damage to the engine or emissions system and to ensure optimal performance.

5. What are the repair options for fixing the NOx Sensor 1 Signal Circuit Low Voltage issue in a Chevrolet?

- Repair options may include replacing the NOx sensor, repairing damaged wiring or connectors, resetting the fault codes, or seeking professional assistance for a more thorough diagnosis and repair.

6. Are there any DIY tips for troubleshooting the P119B code in a Chevrolet?

- DIY enthusiasts can start by checking the sensor connections and wiring for any visible damage, ensuring proper grounding, and using a multimeter to test voltage output according to manufacturer specifications.

7. How critical is it to address the P119B NOx sensor code in a Chevrolet promptly?

- Prompt attention to the issue is recommended to prevent potential damage to the vehicle's emissions system, ensure compliance with environmental regulations, and maintain optimal engine performance.

8. Can weather conditions affect the triggering of the P119B code related to the NOx sensor in a Chevrolet?

- Extreme weather conditions or exposure to moisture may contribute to sensor malfunctions or wiring issues, potentially leading to the triggering of the P119B code.

9. Is it possible for a loose gas cap to trigger the P119B code in a Chevrolet?

- While a loose gas cap is more likely to trigger evaporative emission-related codes, it is not typically associated with the NOx Sensor 1 Signal Circuit Low Voltage code P119B.

10. How can regular maintenance help prevent issues related to the NOx sensor and the P119B code in a Chevrolet?

- Regular maintenance, including timely inspections, sensor checks, and addressing any warning lights promptly, can help prevent issues with the NOx sensor and reduce the likelihood of triggering the P119B code.