AutoCodes – GMC – P116A GMC

P116A GMC Code - O2 Signal 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: P116A GMC indicates O2 Signal 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 1,167

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 P116A 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 P116A GMC - O2 Signal Circuit (NOx Sensor 1) - AutoCodes.com — P116A GMC Code - O2 Signal Circuit (NOx Sensor 1)

What does this mean?

What are the Possible Causes of the DTC P116A 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 P116A 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 P116A 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.

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Information for Specific GMC Models

P116A 2014 GMC Sierra — O2 Signal Circuit (NOx Sensor 1)
P116A 2015 GMC Sierra — O2 Signal Circuit (NOx Sensor 1)
P116A 2016 GMC Sierra — O2 Signal Circuit (NOx Sensor 1)
P116A 2017 GMC Sierra — O2 Signal Circuit (NOx Sensor 1)
P116A 2018 GMC Sierra — O2 Signal Circuit (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 P116A GMC Code

1. What are common symptoms of OBDII code P116A GMC (O2 Signal Circuit - NOx Sensor 1)?

- Common symptoms include decreased fuel efficiency, rough idling, engine misfires, and the illumination of the Check Engine Light.

2. What causes OBDII code P116A GMC to trigger?

- This code is typically triggered by issues with the NOx sensor 1 signal circuit, such as sensor wiring problems, sensor failure, or issues with the sensor's connection.

3. How can I diagnose the O2 signal circuit issue related to code P116A GMC?

- Diagnosing this issue involves checking the wiring harness for any damage or corrosion, testing the NOx sensor 1 for proper function, and ensuring there are no loose connections.

4. Can a faulty NOx sensor 1 cause code P116A GMC to appear?

- Yes, a faulty NOx sensor 1 can cause code P116A to appear, as it directly impacts the signal circuit related to the oxygen sensor.

5. Are there any DIY repair tips for fixing OBDII code P116A GMC?

- DIY repair tips include checking and repairing any damaged wiring, replacing the NOx sensor 1 if faulty, and clearing the code with an OBDII scanner after making repairs.

6. How critical is it to address OBDII code P116A GMC promptly?

- It is important to address this code promptly to prevent potential issues with the vehicle's emissions system and to ensure optimal engine performance.

7. What role does the NOx sensor 1 play in the vehicle's emissions system?

- The NOx sensor 1 is responsible for monitoring and measuring the level of nitrogen oxide emissions in the exhaust system to help the vehicle meet emissions standards.

8. Can driving with OBDII code P116A GMC cause further damage to the vehicle?

- Continuing to drive with this code may lead to decreased fuel efficiency, potential damage to the catalytic converter, and increased emissions output.

9. Is it safe to reset the Check Engine Light after addressing code P116A GMC?

- Yes, it is safe to reset the Check Engine Light using an OBDII scanner after addressing and repairing the underlying issue causing code P116A.

10. How can a professional mechanic help with diagnosing and repairing OBDII code P116A GMC?

- A professional mechanic can use specialized diagnostic tools to pinpoint the exact cause of the issue, perform thorough inspections, and expertly repair the NOx sensor 1 signal circuit for optimal performance.