AutoCodes – GMC – P115F GMC

P115F GMC Code - O2 Reference Voltage Circuit Low Voltage (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: P115F GMC indicates O2 Reference Voltage Circuit Low Voltage (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 360

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 P115F 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 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 P115F GMC - O2 Reference Voltage Circuit Low Voltage (NOx Sensor 1) - AutoCodes.com — P115F GMC Code - O2 Reference Voltage Circuit Low Voltage (NOx Sensor 1)

What does this mean?

What are the Possible Causes of the DTC P115F 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 P115F 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 P115F 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 P115F GMC code?

Need more information on how to fix the P115F GMC code? Get Access to Factory Service Manuals

Need Help with the Code?

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Information for Specific GMC Models

P115F 2014 GMC Sierra — O2 Reference Voltage Circuit Low Voltage (NOx Sensor 1)
P115F 2015 GMC Sierra — O2 Reference Voltage Circuit Low Voltage (NOx Sensor 1)
P115F 2016 GMC Sierra — O2 Reference Voltage Circuit Low Voltage (NOx Sensor 1)
P115F 2017 GMC Sierra — O2 Reference Voltage Circuit Low Voltage (NOx Sensor 1)
P115F 2018 GMC Sierra — O2 Reference Voltage Circuit Low Voltage (NOx Sensor 1)

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 P115F GMC Code

1. What are the common symptoms of OBDII code P115F in a GMC vehicle?

- Common symptoms include poor engine performance, reduced fuel efficiency, illuminated Check Engine light, and potential failure to pass emissions testing.

2. What causes the O2 Reference Voltage Circuit Low Voltage (NOx Sensor 1) code P115F in a GMC?

- The code P115F is often triggered by issues such as a faulty NOx sensor, damaged wiring, poor electrical connections, or a failed powertrain control module (PCM).

3. How serious is the O2 Reference Voltage Circuit Low Voltage (NOx Sensor 1) code P115F in a GMC?

- While the code itself may not cause immediate harm to the vehicle, it can lead to increased emissions, reduced engine efficiency, and potential long-term damage if left unaddressed.

4. Can I continue driving my GMC with the P115F trouble code?

- It is not recommended to continue driving with the P115F code present, as unresolved issues related to the NOx sensor can impact engine performance and emissions control.

5. How can I diagnose and repair the O2 Reference Voltage Circuit Low Voltage (NOx Sensor 1) code P115F in my GMC?

- Diagnosis typically involves checking the NOx sensor, inspecting related wiring and connectors, and testing the PCM. Repair may involve sensor replacement, wiring repairs, or PCM reprogramming.

6. Will resetting the trouble codes make the P115F code go away permanently?

- Simply resetting the trouble codes may temporarily clear the Check Engine light, but if the underlying issue causing the P115F code is not addressed, the code is likely to return.

7. Can a DIY enthusiast fix the O2 Reference Voltage Circuit Low Voltage (NOx Sensor 1) code P115F issue?

- Depending on the skill level and tools available, DIY enthusiasts may be able to diagnose and repair simple causes of the P115F code, such as checking and cleaning connectors or replacing the NOx sensor.

8. How much does it cost to repair the P115F code related to the O2 Reference Voltage Circuit Low Voltage (NOx Sensor 1) in a GMC?

- Repair costs can vary depending on the specific issue causing the code, but expenses may include parts such as a new NOx sensor, labor for diagnosis and repair, and potential costs for wiring repairs.

9. Can the O2 Reference Voltage Circuit Low Voltage (NOx Sensor 1) code P115F cause other problems in my GMC?

- If left unresolved, the P115F code can lead to increased emissions, reduced engine efficiency, and potential damage to other components in the emissions control system.

10. How often should I have the NOx sensor and related components inspected to prevent the recurrence of the P115F trouble code?

- It is recommended to include NOx sensor and related components in regular vehicle maintenance checks, such as during tune-ups or scheduled inspections, to prevent issues that can trigger the P115F code.