AutoCodes – Cadillac – P119B Cadillac

P119B Cadillac 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 Cadillac 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 317

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 P119B Cadillac 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 Cadillac - NOx Sensor 1 Signal Circuit Low Voltage - AutoCodes.com — P119B Cadillac Code - NOx Sensor 1 Signal Circuit Low Voltage

What does this mean?

What are the Possible Causes of the DTC P119B Cadillac?

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 Cadillac?

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 Cadillac 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.

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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 Cadillac Code

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

- Common symptoms include poor engine performance, decreased fuel efficiency, and the illumination of the Check Engine Light.

2. What are the possible causes of the NOx Sensor 1 Signal Circuit Low Voltage code in a Cadillac?

- Potential causes include a faulty NOx sensor, damaged wiring or connectors, issues with the sensor circuit, or a malfunctioning engine control module.

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

- Diagnosing this issue typically involves using an OBDII scanner to retrieve the specific fault code, inspecting the NOx sensor and related wiring for damage, and testing the sensor's voltage output.

4. Can I continue driving my Cadillac with the P119B code related to the NOx Sensor issue?

- It is not recommended to continue driving the vehicle with this code present, as it can lead to further engine damage and potential safety issues. It's best to address the problem promptly.

5. How can I repair the NOx Sensor 1 Signal Circuit Low Voltage problem in my Cadillac?

- Repair options may include replacing the NOx sensor, repairing or replacing damaged wiring or connectors, resetting the engine control module, or seeking professional assistance for further diagnosis and repair.

6. Will resetting the Check Engine Light resolve the P119B code related to the NOx Sensor issue in my Cadillac?

- Simply resetting the Check Engine Light may temporarily clear the code, but it will not fix the underlying problem causing the NOx Sensor 1 Signal Circuit Low Voltage issue.

7. Are there any DIY tips for troubleshooting the NOx Sensor 1 Signal Circuit Low Voltage fault in a Cadillac?

- DIY tips include visually inspecting the sensor and wiring, ensuring proper connections, checking for corrosion, and verifying voltage levels with a multimeter.

8. How important is the NOx sensor in a Cadillac, and what role does it play in vehicle operation?

- The NOx sensor is crucial for monitoring and controlling nitrogen oxide emissions, helping maintain optimal engine performance, fuel efficiency, and adherence to environmental regulations.

9. What are the potential consequences of ignoring the P119B code related to the NOx Sensor in a Cadillac?

- Ignoring this code can lead to increased emissions, decreased fuel efficiency, engine performance issues, potential damage to the catalytic converter, and possible failure to pass emissions testing.

10. Is it necessary to visit a dealership or mechanic for the repair of the NOx Sensor 1 Signal Circuit Low Voltage issue in a Cadillac?

- While some repairs may require specialized tools and expertise, basic troubleshooting steps can be performed by DIY enthusiasts. For more complex issues, seeking professional help is recommended to ensure proper diagnosis and repair.