Engine-Codes.com
Engine-Codes – GMC – P118F 2018 GMC Sierra

P118F 2018 GMC Sierra Code - Exhaust Gas Temperature Sensor 2 Performance Engine Running

Quick Answer

The P118F diagnostic trouble code (DTC) for a 2018 GMC Sierra relates to the Exhaust Gas Temperature Sensor 2 Performance Engine Running. Common causes include Faulty Exhaust Gas Temperature Sensor: The sensor itself may be malfunctioning and providing incorrect readings to the ECM, Wiring Issues: Damaged or corroded wiring connected to the exhaust gas temperature sensor can disrupt the signal transmission, Sensor Connector Problems: A loose or damaged sensor connector can also lead to performance issues. 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 2018 GMC Sierra indicates Exhaust Gas Temperature Sensor 2 Performance Engine Running.
Common causes
Common causes include Faulty Exhaust Gas Temperature Sensor: The sensor itself may be malfunctioning and providing incorrect readings to the ECM, Wiring Issues: Damaged or corroded wiring connected to the exhaust gas temperature sensor can disrupt the signal transmission, Sensor Connector Problems: A loose or damaged sensor connector can also lead to performance issues.
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.
What is this?
Table of contents Created and updated by William Orellana on Sep 17, 2024
💬 Need more help? Ask Auto Expert for instant answers — it's free!
AutoCodes App

Fix Your Car Smarter

Try the New AutoCodes App!

Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.

AutoCodes App on Google Play

Code P118F 2018 GMC Sierra Description

The P118F diagnostic trouble code (DTC) for a 2018 GMC Sierra relates to the Exhaust Gas Temperature Sensor 2 Performance Engine Running. This code indicates that there is a problem with the performance of the exhaust gas temperature sensor while the engine is running. The exhaust gas temperature sensor is a crucial component in monitoring the temperature of the exhaust gases leaving the engine. This information is used by the engine control module (ECM) to adjust fuel delivery and optimize engine performance.

OBDII Code P118F 2018 GMC Sierra - Exhaust Gas Temperature Sensor 2 Performance Engine Running
P118F 2018 GMC Sierra Code - Exhaust Gas Temperature Sensor 2 Performance Engine Running

Common Causes of P118F 2018 GMC Sierra

  1. Faulty Exhaust Gas Temperature Sensor: The sensor itself may be malfunctioning and providing incorrect readings to the ECM.
  2. Wiring Issues: Damaged or corroded wiring connected to the exhaust gas temperature sensor can disrupt the signal transmission.
  3. Sensor Connector Problems: A loose or damaged sensor connector can also lead to performance issues.
  4. ECM Malfunction: In rare cases, a problem with the engine control module can cause the P118F code to appear.

Symptoms of P118F 2018 GMC Sierra

  1. Check Engine Light: The most common symptom associated with the P118F code is the illumination of the check engine light on the vehicle's dashboard.
  2. Reduced Fuel Efficiency: A malfunctioning exhaust gas temperature sensor can lead to decreased fuel efficiency as the engine may not be running optimally.
  3. Rough Idling: The engine may experience rough idling or hesitation when the exhaust gas temperature sensor is not functioning correctly.
  4. Poor Acceleration: Acceleration may feel sluggish or delayed due to incorrect temperature readings from the sensor.
  5. Engine Misfires: In severe cases, the engine may experience misfires, causing a noticeable decrease in performance.

How to Fix P118F 2018 GMC Sierra

  1. Diagnose the Issue: Use a scan tool to read the DTC and pinpoint the exact cause of the problem.
  2. Inspect Wiring and Connectors: Check the wiring and connectors associated with the exhaust gas temperature sensor for any damage or corrosion.
  3. Replace Exhaust Gas Temperature Sensor: If the sensor is faulty, replace it with a new, OEM-quality sensor.
  4. Clear DTC: After making the necessary repairs, clear the DTC from the ECM's memory to reset the check engine light.
  5. Test Drive: Take the vehicle for a test drive to ensure that the issue has been resolved and that the check engine light does not reappear.

Cost to Fix P118F 2018 GMC Sierra

The typical repair costs for addressing the P118F code on a 2018 GMC Sierra can vary depending on the specific cause of the issue. In general, replacing the exhaust gas temperature sensor and addressing any wiring or connector problems can range from $200 to $500, including parts and labor. However, it's important to note that diagnosis time and labor rates at auto repair shops can fluctuate based on various factors. Rates typically range between $80 and $150 per hour, with higher rates in metropolitan areas or at dealerships and lower rates at independent shops. For a more accurate estimate, it's recommended to inquire with local auto repair shops.

Need more information about the P118F 2018 GMC Sierra code?

Need more information on how to fix the P118F 2018 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P118F 2018 GMC Sierra code diagnosed by a professional: Find a repair shop in your area

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 2018 GMC Sierra Code

1. What does the OBDII code P118F mean on a 2018 GMC Sierra?

P118F indicates a performance issue with Exhaust Gas Temperature (EGT) Sensor 2 while the engine is running. This sensor monitors exhaust temperatures to optimize emissions and engine performance.

2. What are the common symptoms of the P118F code?

Symptoms may include an illuminated check engine light, reduced engine performance, poor fuel efficiency, and potential emissions test failure.

3. What causes the P118F code to appear?

Common causes include a faulty EGT sensor 2, damaged wiring or connectors, excessive soot buildup on the sensor, or an exhaust system issue affecting sensor performance.

4. Can driving with the P118F code damage my 2018 GMC Sierra?

While it may not cause immediate damage, prolonged driving with this code can lead to increased emissions, reduced fuel efficiency, and potential damage to the exhaust system or catalytic converter.

5. How do I diagnose the P118F code?

Start by scanning for codes with an OBDII scanner, inspecting the wiring and connectors for damage, and testing the EGT sensor 2 for proper voltage and resistance readings.

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

Repairs may include replacing the faulty EGT sensor 2, cleaning soot buildup, repairing damaged wiring or connectors, or addressing any exhaust system issues.

7. Is the P118F code specific to EGT Sensor 2?

Yes, the code specifically refers to a performance issue with Exhaust Gas Temperature Sensor 2, which is typically located downstream in the exhaust system.

8. How much does it cost to repair the P118F code?

The cost varies depending on the issue. Replacing an EGT sensor typically costs $100-$300, while wiring repairs or exhaust system fixes may cost more.

9. Can a software update fix the P118F code?

In rare cases, a software update to the engine control module (ECM) may resolve the issue if it’s related to programming. Consult a dealership or qualified mechanic to confirm.

10. How can I prevent the P118F code from recurring?

Regular maintenance, such as keeping the exhaust system clean, inspecting wiring and connectors, and performing periodic checks on sensors, can help prevent this code from reoccurring.

Discuss the causes and fixes for P118F 2018 GMC Sierra OBDII Code

Submit a New Comment

Code P118F 2018 GMC Sierra comments

No comments found for this page.