AutoCodes – GMC – P118F 2017 GMC Sierra

P118F 2017 GMC Sierra Code - Exhaust Gas Temperature Sensor 2 Performance Engine Running

Quick Answer

The exhaust gas temperature sensors are variable resistors that measure the temperature of the exhaust gas. Common causes include Faulty Exhaust Gas Temperature Sensor, Exhaust Gas Temperature Sensor harness is open or shorted, Exhaust Gas Temperature 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: P118F 2017 GMC Sierra indicates Exhaust Gas Temperature Sensor 2 Performance Engine Running.
Common causes: Common causes include Faulty Exhaust Gas Temperature Sensor, Exhaust Gas Temperature Sensor harness is open or shorted, Exhaust Gas Temperature 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 223

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 P118F 2017 GMC Sierra Description

The exhaust gas temperature sensors are variable resistors that measure the temperature of the exhaust gas. The exhaust temperature sensor 1 is the first exhaust temperature sensor on the exhaust system, the following exhaust temperature sensors are counted upward from the engine outlet to the exhaust system end. The Engine Control Module (ECM) supplies 5 V to the exhaust gas temperature signal circuit and supplies a ground to the low reference circuit. The exhaust gas temperature sensor temperature information is used by the ECM during the exhaust gas particulate filter cleaning process. The Diagnostic Trouble Code (DTC) will be set if the ECM detects that the difference between measured exhaust gas temperature and the estimated exhaust gas temperature is greater than a calibrated amount for greater than 1 s.

OBDII Code P118F 2017 GMC Sierra - Exhaust Gas Temperature Sensor 2 Performance Engine Running - AutoCodes.com — P118F 2017 GMC Sierra Code - Exhaust Gas Temperature Sensor 2 Performance Engine Running

What does this mean?

What are the Possible Causes of the DTC P118F 2017 GMC Sierra?

Faulty Exhaust Gas Temperature Sensor
Exhaust Gas Temperature Sensor harness is open or shorted
Exhaust Gas Temperature Sensor circuit poor electrical connection
Faulty Engine Control Module (ECM)

How to Fix the DTC P118F 2017 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 P118F 2017 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 P118F 2017 GMC Sierra 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 P118F 2017 GMC Sierra Code

1. What does the OBDII code P118F mean on a 2017 GMC Sierra?

P118F indicates an issue with the performance of Exhaust Gas Temperature (EGT) Sensor 2 while the engine is running, often related to improper temperature readings.

2. What are the symptoms of code P118F on a 2017 GMC Sierra?

Common symptoms include an illuminated check engine light, reduced engine performance, poor fuel efficiency, or the vehicle entering limp mode.

3. What causes the P118F code to appear?

Potential causes include a faulty EGT sensor, damaged wiring or connectors, excessive soot buildup on the sensor, or issues with the exhaust system.

4. Can I drive my 2017 GMC Sierra with a P118F code?

Driving with this code is not recommended, as it could lead to further damage to the exhaust or emissions system and may cause reduced engine performance.

5. How do I diagnose the P118F code on my GMC Sierra?

Diagnosis involves using a scan tool to confirm the code, inspecting the EGT sensor and its wiring for damage, and testing the sensor for proper function using a multimeter.

6. How do I fix the P118F code on a 2017 GMC Sierra?

Repairs may include replacing the faulty EGT sensor, cleaning soot buildup, repairing damaged wiring or connectors, and addressing any exhaust system issues.

7. How much does it cost to fix a P118F code on a GMC Sierra?

The cost can vary, but replacing an EGT sensor typically ranges from $150 to $300, including parts and labor, depending on your location and mechanic.

8. What is EGT Sensor 2 on a 2017 GMC Sierra?

EGT Sensor 2 measures the temperature of exhaust gases downstream in the exhaust system to help the engine control module (ECM) optimize performance and emissions.

9. Can a P118F code cause long-term damage if ignored?

Yes, ignoring this code can result in damage to the exhaust system, catalytic converter, or diesel particulate filter (DPF), leading to more expensive repairs.

10. Does the P118F code always mean the EGT sensor is faulty?

Not always. It can also be triggered by wiring issues, soot accumulation, or problems with the exhaust system, so proper diagnosis is crucial.