AutoCodes – GMC – P115E 2018 GMC Sierra

P115E 2018 GMC Sierra 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 2018 GMC Sierra 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 201

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 P115E 2018 GMC Sierra 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 2018 GMC Sierra - O2 Reference Voltage Circuit (NOx Sensor 1) - AutoCodes.com — P115E 2018 GMC Sierra Code - O2 Reference Voltage Circuit (NOx Sensor 1)

What does this mean?

What are the Possible Causes of the DTC P115E 2018 GMC Sierra?

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 2018 GMC Sierra?

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 2018 GMC Sierra 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 P115E 2018 GMC Sierra code?

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Need Help with the Code?

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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 2018 GMC Sierra Code

1. What does the OBDII code P115E mean on a 2018 GMC Sierra?

P115E indicates an issue with the O2 reference voltage circuit for NOx Sensor 1, which is responsible for monitoring nitrogen oxide levels in the exhaust system.

2. What are the common symptoms of code P115E in a 2018 GMC Sierra?

Symptoms include the check engine light being illuminated, reduced fuel efficiency, poor engine performance, and potential limp mode activation.

3. What causes the P115E code to appear on a 2018 GMC Sierra?

Common causes include a faulty NOx sensor, damaged wiring or connectors in the O2 reference voltage circuit, or a malfunctioning engine control module (ECM).

4. Can I drive my 2018 GMC Sierra with the P115E code?

While the truck may still operate, driving with this code can lead to reduced performance, increased emissions, and potential damage to the catalytic converter if not addressed.

5. How do I diagnose the P115E code on a 2018 GMC Sierra?

Diagnose the code by checking for damaged or corroded wiring and connectors, testing the NOx sensor with a multimeter, and using a scan tool to monitor sensor data and verify proper operation.

6. How do I fix the P115E code on a 2018 GMC Sierra?

Repairs may include replacing the faulty NOx sensor, repairing or replacing damaged wiring or connectors, or in rare cases, reprogramming or replacing the ECM.

7. How much does it cost to repair the P115E code on a 2018 GMC Sierra?

Repair costs vary but typically range from $300 to $800, depending on whether the NOx sensor or wiring needs replacement.

8. Can a dirty exhaust system cause the P115E code on a 2018 GMC Sierra?

While unlikely, excessive soot or buildup in the exhaust system can affect NOx sensor performance, leading to this code.

9. How does the NOx sensor affect engine performance in a 2018 GMC Sierra?

The NOx sensor helps regulate emissions and optimize engine performance by providing accurate data to the ECM. A malfunction can result in poor fuel economy and reduced power.

10. Will clearing the P115E code solve the problem on a 2018 GMC Sierra?

Clearing the code may temporarily turn off the check engine light, but the underlying issue must be addressed to prevent the code from returning.