AutoCodes – Chevrolet – P119B 2018 Chevrolet Silverado

P119B 2018 Chevrolet Silverado 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 2018 Chevrolet Silverado 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 243

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 Mar 24, 2024

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P119B 2018 Chevrolet Silverado 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 2018 Chevrolet Silverado - NOx Sensor 1 Signal Circuit Low Voltage - AutoCodes.com — P119B 2018 Chevrolet Silverado Code - NOx Sensor 1 Signal Circuit Low Voltage

What does this mean?

What are the Possible Causes of the DTC P119B 2018 Chevrolet Silverado?

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 2018 Chevrolet Silverado?

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 2018 Chevrolet Silverado 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 2018 Chevrolet Silverado code?

Need more information on how to fix the P119B 2018 Chevrolet Silverado code? Get Access to Factory Service Manuals

Need Help with the Code?

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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 2018 Chevrolet Silverado Code

1. What are the common symptoms of OBDII code P119B in a 2018 Chevrolet Silverado related to the NOx Sensor 1 Signal Circuit Low Voltage?

- Common symptoms include poor engine performance, reduced fuel efficiency, and illuminated check engine light.

2. What are the possible causes of the NOx Sensor 1 Signal Circuit Low Voltage error code in a 2018 Chevrolet Silverado?

- Possible causes may include a faulty NOx sensor, damaged wiring or connectors, issues with the exhaust system, or a malfunctioning ECM.

3. How can I diagnose the NOx Sensor 1 Signal Circuit Low Voltage issue in my 2018 Chevrolet Silverado?

- You can diagnose the problem by using an OBDII scanner to retrieve the specific code, visually inspecting the sensor and wiring for damage, and testing the sensor's voltage output.

4. Can I continue driving my 2018 Chevrolet Silverado with the P119B code related to the NOx Sensor 1 Signal Circuit Low Voltage?

- It is not recommended to drive your vehicle with this code as it can lead to further damage and may cause your vehicle to fail emissions tests.

5. What are some repair tips for fixing the NOx Sensor 1 Signal Circuit Low Voltage problem in a 2018 Chevrolet Silverado?

- Repair tips include checking and repairing any damaged wiring or connectors, replacing the NOx sensor if necessary, and clearing the error code with an OBDII scanner after making repairs.

6. Is it possible to reset the OBDII code P119B related to the NOx Sensor 1 Signal Circuit Low Voltage without fixing the underlying issue?

- While you can clear the code temporarily, it will likely reappear if the root cause of the problem is not addressed. It is important to diagnose and fix the issue to prevent further complications.

7. How much does it typically cost to repair the NOx Sensor 1 Signal Circuit Low Voltage problem in a 2018 Chevrolet Silverado?

- The cost of repair can vary depending on the exact issue, but it may involve expenses for parts such as a new NOx sensor and labor fees for the repairs.

8. Can a DIY enthusiast fix the NOx Sensor 1 Signal Circuit Low Voltage error code in a 2018 Chevrolet Silverado?

- While some experienced DIY enthusiasts may be able to diagnose and repair the issue, dealing with sensors and electrical components can be complex, so it's recommended to seek professional help if unsure.

9. Will fixing the NOx Sensor 1 Signal Circuit Low Voltage error improve the performance and fuel efficiency of my 2018 Chevrolet Silverado?

- Yes, addressing the issue should help restore proper engine performance and fuel efficiency, as the NOx sensor plays a crucial role in emission control and engine management.

10. How often does the NOx Sensor 1 Signal Circuit Low Voltage error occur in a 2018 Chevrolet Silverado, and is it a common issue among owners?

- While the frequency of occurrence can vary, this error is not uncommon in vehicles equipped with NOx sensors, and it may require attention over the life of the vehicle for some owners.