AutoCodes – GMC – P119C GMC

P119C GMC Code - NOx Sensor 1 Signal Circuit High 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: P119C GMC indicates NOx Sensor 1 Signal Circuit High 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 364

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 29, 2024

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P119C 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 P119C GMC - NOx Sensor 1 Signal Circuit High Voltage - AutoCodes.com — P119C GMC Code - NOx Sensor 1 Signal Circuit High Voltage

What does this mean?

What are the Possible Causes of the DTC P119C GMC?

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 P119C 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 P119C 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 P119C GMC code?

Need more information on how to fix the P119C GMC code? Get Access to Factory Service Manuals

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Information for Specific GMC Models

P119C 2014 GMC Sierra — NOx Sensor 1 Signal Circuit High Voltage
P119C 2015 GMC Sierra — NOx Sensor 1 Signal Circuit High Voltage
P119C 2016 GMC Sierra — NOx Sensor 1 Signal Circuit High Voltage
P119C 2017 GMC Sierra — NOx Sensor 1 Signal Circuit High Voltage
P119C 2018 GMC Sierra — NOx Sensor 1 Signal Circuit High 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 P119C GMC Code

1. What are the common symptoms of OBDII code P119C GMC (NOx Sensor 1 Signal Circuit High Voltage)?

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

2. What are the possible causes of OBDII code P119C GMC?

- The code P119C GMC can be triggered by issues such as a faulty NOx sensor, damaged wiring or connectors, or a problem with the engine control module (ECM).

3. How can I diagnose the NOx sensor 1 signal circuit high voltage issue?

- Diagnosing this issue typically involves using a diagnostic scanner to retrieve the specific trouble code, checking the wiring and connectors for damage, and testing the NOx sensor's functionality.

4. Can a high voltage reading from the NOx sensor cause any further damage to the vehicle?

- A high voltage reading from the NOx sensor can potentially lead to increased emissions, reduced engine performance, and may cause damage to other emission control components if left unresolved.

5. Is it safe to continue driving with OBDII code P119C GMC present?

- It is not recommended to drive with the code P119C GMC active, as it can result in poor engine performance and potentially harm the vehicle's emission system.

6. How can I repair OBDII code P119C GMC related to the NOx sensor 1 signal circuit high voltage?

- Repairing this issue may involve replacing the faulty NOx sensor, repairing damaged wiring or connectors, or reprogramming the engine control module (ECM) if necessary.

7. Are there any DIY tips for troubleshooting OBDII code P119C GMC at home?

- DIY troubleshooting tips include checking the NOx sensor's wiring for visible damage, ensuring proper connector connections, and using a diagnostic scanner to clear the code for temporary testing.

8. How long does it typically take to repair OBDII code P119C GMC in a GMC vehicle?

- The repair time for OBDII code P119C GMC can vary depending on the specific cause of the issue, but it generally takes a few hours to a full day for diagnosis and repair.

9. Can resetting the check engine light resolve OBDII code P119C GMC temporarily?

- Resetting the check engine light may temporarily clear the code, but if the underlying issue causing the high voltage reading from the NOx sensor is not addressed, the code is likely to reappear.

10. Is it necessary to visit a professional mechanic for resolving OBDII code P119C GMC, or can I fix it myself?

- While some DIY troubleshooting and repairs are possible, resolving OBDII code P119C GMC related to the NOx sensor 1 signal circuit high voltage often requires specialized diagnostic tools and expertise, so seeking help from a professional mechanic is recommended.