AutoCodes – Cadillac – P115E Cadillac

P115E Cadillac Code - O2 Reference Voltage Circuit (NOx Sensor 1)

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: P115E Cadillac indicates O2 Reference Voltage Circuit (NOx Sensor 1).
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 466

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 29, 2024

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P115E 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 P115E Cadillac - O2 Reference Voltage Circuit (NOx Sensor 1) - AutoCodes.com — P115E Cadillac Code - O2 Reference Voltage Circuit (NOx Sensor 1)

What does this mean?

What are the Possible Causes of the DTC P115E 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 P115E 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 P115E 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 P115E Cadillac Code

1. What does OBDII code P115E (Cadillac) indicate?

The code P115E in a Cadillac refers to an O2 reference voltage circuit issue related to the NOx sensor 1.

2. What are the common symptoms of O2 Reference Voltage Circuit (NOx Sensor 1) error (P115E) in a Cadillac?

Common symptoms include poor engine performance, rough idling, decreased fuel efficiency, and potentially an illuminated check engine light.

3. What are the possible causes of OBDII code P115E in a Cadillac?

Potential causes of the P115E code include faulty wiring or connections, a malfunctioning NOx sensor, a damaged O2 sensor, or issues with the vehicle's ECM.

4. How can I diagnose the O2 Reference Voltage Circuit error (P115E) in my Cadillac?

Diagnosing P115E involves using an OBDII scanner to retrieve the code, inspecting the wiring and connectors for damage, and testing the NOx sensor and O2 sensor for proper functionality.

5. Is it safe to continue driving my Cadillac with OBDII code P115E (O2 Reference Voltage Circuit issue)?

Continuing to drive with the P115E code may lead to reduced fuel efficiency and potential damage to other engine components. It is recommended to address the issue promptly.

6. Can I repair the O2 Reference Voltage Circuit error (P115E) in my Cadillac myself?

Repairing the P115E code may involve simple tasks like checking and cleaning connectors or more complex tasks like replacing sensors. Depending on your expertise, you may be able to repair it yourself or seek professional help.

7. How much does it typically cost to repair OBDII code P115E in a Cadillac?

The cost of repairing the P115E code can vary depending on the underlying issue. Simple fixes like connector cleaning may be inexpensive, while sensor replacements or ECM repairs can be more costly.

8. Will resetting the check engine light resolve the O2 Reference Voltage Circuit error (P115E) in my Cadillac?

Resetting the check engine light may temporarily clear the code, but if the underlying issue is not addressed, the code is likely to return. It is important to diagnose and repair the root cause of the problem.

9. How long does it usually take to repair OBDII code P115E in a Cadillac?

The repair time for the P115E code can vary based on the specific issue and the expertise of the person performing the repairs. Simple fixes may take less than an hour, while more complex repairs could take several hours.

10. Can a P115E OBDII code affect the emissions output of my Cadillac?

Yes, a P115E code related to the O2 reference voltage circuit can impact the emissions output of your Cadillac, potentially causing it to fail emissions tests and contribute to increased environmental pollution.