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P11FE Cadillac Code - O2 Low Reference Circuit High Voltage (NOx Sensor 2)

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: P11FE Cadillac indicates O2 Low Reference Circuit High Voltage (NOx Sensor 2).
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 396

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 P11FE 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 P11FE Cadillac - O2 Low Reference Circuit High Voltage (NOx Sensor 2) - AutoCodes.com — P11FE Cadillac Code - O2 Low Reference Circuit High Voltage (NOx Sensor 2)

What does this mean?

What are the Possible Causes of the DTC P11FE Cadillac?

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 P11FE 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 P11FE 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 P11FE Cadillac Code

1. What are the common symptoms of OBDII code P11FE in a Cadillac related to the O2 Low Reference Circuit High Voltage (NOx Sensor 2)?

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

2. What are the possible causes of OBDII code P11FE in a Cadillac indicating an issue with the O2 Low Reference Circuit High Voltage (NOx Sensor 2)?

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

3. How can I diagnose OBDII code P11FE in my Cadillac linked to the O2 Low Reference Circuit High Voltage (NOx Sensor 2)?

- Diagnosis typically involves using an OBDII scanner to retrieve the specific fault code, conducting a visual inspection of the sensor and its wiring, and performing voltage and continuity tests.

4. Are there any specific repair tips for addressing OBDII code P11FE related to the O2 Low Reference Circuit High Voltage (NOx Sensor 2) in a Cadillac?

- Repair tips may include checking and repairing any damaged wiring or connectors, replacing the NOx sensor if necessary, and resetting the fault code after completing repairs.

5. Can driving with OBDII code P11FE present in a Cadillac due to the O2 Low Reference Circuit High Voltage (NOx Sensor 2) cause further damage to the vehicle?

- Continuing to drive with this fault code may lead to reduced engine performance and fuel efficiency, so it is recommended to address the issue promptly to prevent any potential long-term damage.

6. Is it possible to reset OBDII code P11FE related to the O2 Low Reference Circuit High Voltage (NOx Sensor 2) in a Cadillac without addressing the underlying issue?

- While you can clear the fault code using an OBDII scanner, it is important to diagnose and repair the root cause to prevent the code from reappearing and potentially causing further issues.

7. Are there any recalls or technical service bulletins related to OBDII code P11FE concerning the O2 Low Reference Circuit High Voltage (NOx Sensor 2) in Cadillac vehicles?

- Checking with a Cadillac dealership or accessing online databases for recalls and technical service bulletins specific to your vehicle model and year is recommended to determine any related information.

8. How long does it typically take to repair OBDII code P11FE in a Cadillac due to the O2 Low Reference Circuit High Voltage (NOx Sensor 2)?

- The repair time can vary depending on the exact cause of the issue, but it may take anywhere from a few hours to a full day to diagnose, repair, and clear the fault code.

9. Is it possible to prevent OBDII code P11FE from occurring in a Cadillac related to the O2 Low Reference Circuit High Voltage (NOx Sensor 2)?

- Regular maintenance, including timely sensor inspections and addressing any wiring issues promptly, can help prevent the occurrence of this fault code in your Cadillac.

10. Can a DIY enthusiast with some automotive knowledge address OBDII code P11FE related to the O2 Low Reference Circuit High Voltage (NOx Sensor 2) in a Cadillac?

- Depending on the specific issue, a DIY enthusiast with the necessary tools and knowledge may be able to diagnose and repair this fault code, but complex issues may require professional assistance.