AutoCodes – GMC – P119D 2015 GMC Sierra

P119D 2015 GMC Sierra Code - NOx Sensor 2 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 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: P119D 2015 GMC Sierra indicates NOx Sensor 2 Signal 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 247

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 24, 2024

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
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Code P119D 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 P119D 2015 GMC Sierra - NOx Sensor 2 Signal Circuit - AutoCodes.com — P119D 2015 GMC Sierra Code - NOx Sensor 2 Signal Circuit

What does this mean?

What are the Possible Causes of the DTC P119D 2015 GMC Sierra?

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 P119D 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 P119D 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 P119D 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 P119D 2015 GMC Sierra Code

1. What does the OBDII code P119D mean on a 2015 GMC Sierra?

P119D indicates a problem with the NOx Sensor 2 Signal Circuit, which monitors nitrogen oxide levels in the exhaust system downstream of the catalytic converter.

2. What are the symptoms of code P119D in a 2015 GMC Sierra?

Common symptoms include reduced engine performance, increased fuel consumption, illuminated check engine light, and possible limp mode activation.

3. What causes the P119D code to appear on a GMC Sierra?

Possible causes include a faulty NOx sensor, damaged wiring or connectors in the NOx sensor circuit, software issues in the engine control module (ECM), or contamination of the sensor by exhaust soot or debris.

4. How do I diagnose the P119D code on a 2015 GMC Sierra?

Diagnosis involves using a scan tool to confirm the code, visually inspecting the NOx sensor and its wiring for damage, testing the sensor's electrical connections, and checking for any exhaust leaks upstream of the sensor.

5. Can I drive my 2015 GMC Sierra with the P119D code?

While the vehicle may still be drivable, ignoring this issue can lead to reduced fuel efficiency, increased emissions, and potential damage to other exhaust system components.

6. How is the P119D code fixed on a GMC Sierra?

Repairs may involve replacing the faulty NOx sensor, repairing or replacing damaged wiring, cleaning contamination from the sensor, or updating the ECM software.

7. How much does it cost to fix code P119D on a 2015 GMC Sierra?

The repair cost varies but typically ranges from $300 to $800, depending on whether the NOx sensor needs replacement and labor rates in your area.

8. Can a bad NOx sensor cause other issues in a 2015 GMC Sierra?

Yes, a faulty NOx sensor can lead to poor engine performance, increased emissions, and potential damage to the selective catalytic reduction (SCR) system.

9. How can I prevent the P119D code from recurring?

Regular maintenance, using high-quality fuel, and keeping the exhaust system clean can help prevent NOx sensor issues. Promptly addressing exhaust leaks or engine malfunctions is also crucial.

10. Is the NOx Sensor 2 the same as the upstream NOx sensor in a GMC Sierra?

No, NOx Sensor 2 refers to the downstream sensor located after the catalytic converter, while the upstream sensor is positioned before the converter.