AutoCodes – GMC – P119D GMC

P119D GMC 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 GMC 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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 819

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
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code P119D GMC 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 GMC - NOx Sensor 2 Signal Circuit - AutoCodes.com — P119D GMC Code - NOx Sensor 2 Signal Circuit

What does this mean?

What are the Possible Causes of the DTC P119D GMC?

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 GMC?

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 GMC 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 GMC code?

Need more information on how to fix the P119D GMC code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P119D GMC code diagnosed by a professional: Find a repair shop in your area

Information for Specific GMC Models

P119D 2014 GMC Sierra — NOx Sensor 2 Signal Circuit
P119D 2015 GMC Sierra — NOx Sensor 2 Signal Circuit
P119D 2016 GMC Sierra — NOx Sensor 2 Signal Circuit
P119D 2017 GMC Sierra — NOx Sensor 2 Signal Circuit
P119D 2018 GMC Sierra — NOx Sensor 2 Signal Circuit

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 GMC Code

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

P119D indicates an issue with the NOx Sensor 2 Signal Circuit, typically related to a malfunction in the second nitrogen oxide (NOx) sensor or its wiring.

2. What are the common symptoms of code P119D on a GMC?

Symptoms may include an illuminated check engine light, reduced engine performance, poor fuel efficiency, or difficulty passing emissions tests.

3. What causes the P119D code to appear?

Possible causes include a faulty NOx sensor, damaged wiring or connectors in the sensor circuit, excessive soot buildup on the sensor, or an issue with the engine control module (ECM).

4. Can a dirty NOx sensor trigger the P119D code?

Yes, excessive soot or contamination on the NOx sensor can impair its readings and trigger the P119D code.

5. How do you diagnose a P119D code?

Diagnosis involves using a scan tool to read live data from the NOx sensor, inspecting the wiring and connectors for damage, and testing the sensorâ€™s resistance and functionality.

6. Can a faulty exhaust system cause the P119D code?

Yes, issues with the exhaust system, such as leaks or excessive soot buildup, can affect the NOx sensorâ€™s performance and trigger the code.

7. Is it safe to drive with a P119D code active?

While the vehicle may still be drivable, ignoring the code can result in reduced performance, increased emissions, and potential damage to the catalytic converter.

8. What is the typical repair for a P119D code?

Repairs may include replacing the faulty NOx sensor, cleaning soot buildup, repairing damaged wiring, or reprogramming the ECM if necessary.

9. How much does it cost to fix a P119D code on a GMC?

Repair costs can vary but typically range from $200 to $600, depending on whether the NOx sensor needs replacement and labor charges.

10. Can clearing the code fix the P119D issue?

Clearing the code without addressing the root cause may temporarily turn off the check engine light, but the issue will likely return until proper repairs are made.