AutoCodes – GMC – P119A 2015 GMC Sierra

P119A 2015 GMC Sierra Code - NOx Sensor 1 Signal 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, 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: P119A 2015 GMC Sierra indicates NOx Sensor 1 Signal Circuit.
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 207

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 P119A 2015 GMC Sierra 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 P119A 2015 GMC Sierra - NOx Sensor 1 Signal Circuit - AutoCodes.com — P119A 2015 GMC Sierra Code - NOx Sensor 1 Signal Circuit

What does this mean?

What are the Possible Causes of the DTC P119A 2015 GMC Sierra?

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 P119A 2015 GMC Sierra?

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 P119A 2015 GMC Sierra 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 P119A 2015 GMC Sierra 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 P119A 2015 GMC Sierra Code

1. What are the common symptoms of OBDII code P119A in a 2015 GMC Sierra related to the NOx Sensor 1 Signal Circuit?

The common symptoms include poor engine performance, decreased fuel efficiency, and the illumination of the check engine light.

2. What are the possible causes of OBDII code P119A in a 2015 GMC Sierra?

Possible causes of this code include a faulty NOx sensor, damaged wiring or connectors in the signal circuit, or issues with the engine control module.

3. How can I diagnose the NOx Sensor 1 Signal Circuit issue causing OBDII code P119A in my 2015 GMC Sierra?

You can diagnose the issue by conducting a visual inspection of the sensor and its connections, checking for any damaged wiring, and using a diagnostic scanner to read the trouble codes.

4. Can I continue driving my 2015 GMC Sierra with OBDII code P119A related to the NOx Sensor 1 Signal Circuit issue?

It is not recommended to continue driving the vehicle with this code present, as it can lead to further engine damage and decreased performance.

5. What are some repair tips for resolving OBDII code P119A in a 2015 GMC Sierra?

Repair tips include checking and replacing the NOx sensor if faulty, repairing any damaged wiring or connectors, and clearing the trouble codes with a diagnostic scanner.

6. Is it possible to reset the check engine light after repairing the NOx Sensor 1 Signal Circuit issue in a 2015 GMC Sierra?

Yes, you can reset the check engine light by using a diagnostic scanner to clear the trouble codes once the issue has been resolved.

7. How much does it typically cost to repair the NOx Sensor 1 Signal Circuit problem causing OBDII code P119A in a 2015 GMC Sierra?

The cost of repair can vary depending on the extent of the damage and the parts needed, but it generally ranges from $200 to $500 for parts and labor.

8. Are there any recalls or technical service bulletins related to OBDII code P119A in a 2015 GMC Sierra?

It's advisable to check with a GMC dealership or visit the National Highway Traffic Safety Administration (NHTSA) website to see if there are any relevant recalls or bulletins for this issue.

9. Can a DIY enthusiast replace the NOx sensor to fix OBDII code P119A in a 2015 GMC Sierra?

While it is possible for experienced DIY enthusiasts to replace the NOx sensor, it is recommended to consult a professional mechanic for proper diagnosis and repair to ensure the issue is resolved correctly.

10. How often should the NOx sensor be inspected or replaced in a 2015 GMC Sierra to prevent OBDII code P119A from occurring?

It's a good practice to have the NOx sensor inspected during routine maintenance checks and replaced as needed to prevent issues like the OBDII code P119A from occurring.