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P0455 2015 GMC Sierra Code - Evaporative Emission System Large Leak Detected

Quick Answer

The P0455 diagnostic trouble code (DTC) for a 2015 GMC Sierra indicates that the vehicle's onboard diagnostic system has detected a large leak in the evaporative emission control system. Common causes include Loose or Damaged Gas Cap: A loose or damaged gas cap is one of the most common causes of the P0455 code, Cracked or Disconnected Hose: A cracked or disconnected hose in the evaporative emission system can lead to a large leak, Faulty Purge Valve: A malfunctioning purge valve can cause the system to not properly seal, resulting in a large leak. Severity is Low - monitor the vehicle and repair when practical. The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.

What it means
P0455 2015 GMC Sierra indicates Evaporative Emission System Large Leak Detected.
Common causes
Common causes include Loose or Damaged Gas Cap: A loose or damaged gas cap is one of the most common causes of the P0455 code, Cracked or Disconnected Hose: A cracked or disconnected hose in the evaporative emission system can lead to a large leak, Faulty Purge Valve: A malfunctioning purge valve can cause the system to not properly seal, resulting in a large leak.
Severity
Low - monitor the vehicle and repair when practical.
Can I drive?
The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.
What is this?
Table of contents Created and updated by William Orellana on Sep 15, 2024
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Code P0455 2015 GMC Sierra Description

The P0455 diagnostic trouble code (DTC) for a 2015 GMC Sierra indicates that the vehicle's onboard diagnostic system has detected a large leak in the evaporative emission control system. The evaporative emission system is responsible for capturing and storing fuel vapors from the fuel tank to prevent them from escaping into the atmosphere. A large leak in this system can lead to increased emissions, decreased fuel efficiency, and potential safety hazards.

OBDII Code P0455 2015 GMC Sierra - Evaporative Emission System Large Leak Detected
P0455 2015 GMC Sierra Code - Evaporative Emission System Large Leak Detected

Common Causes of P0455 2015 GMC Sierra

  1. Loose or Damaged Gas Cap: A loose or damaged gas cap is one of the most common causes of the P0455 code.
  2. Cracked or Disconnected Hose: A cracked or disconnected hose in the evaporative emission system can lead to a large leak.
  3. Faulty Purge Valve: A malfunctioning purge valve can cause the system to not properly seal, resulting in a large leak.
  4. Leak in Fuel Tank: A leak in the fuel tank itself can also trigger the P0455 code.
  5. Evaporative Emission Control System Malfunction: Any malfunction in the components of the evaporative emission control system can lead to a large leak being detected.

Symptoms of P0455 2015 GMC Sierra

  1. Check Engine Light: The most common symptom associated with the P0455 code is the illumination of the check engine light on the vehicle's dashboard.
  2. Strong Fuel Odor: A noticeable fuel odor inside or outside the vehicle may indicate a large leak in the evaporative emission system.
  3. Decreased Fuel Efficiency: A large leak in the system can cause the engine to burn more fuel than necessary, leading to decreased fuel efficiency.
  4. Rough Idle: In some cases, a large leak in the evaporative emission system can cause the engine to run rough or idle erratically.
  5. Failed Emissions Test: If the P0455 code is not addressed, it can lead to failed emissions tests due to increased emissions from the vehicle.

How to Fix P0455 2015 GMC Sierra

  1. Check Gas Cap: Start by checking the gas cap to ensure it is properly tightened and in good condition. Replace if necessary.
  2. Inspect Hoses: Inspect all hoses in the evaporative emission system for cracks, damage, or disconnections. Replace any faulty hoses.
  3. Test Purge Valve: Test the purge valve to ensure it is functioning properly. Replace if necessary.
  4. Check Fuel Tank: Inspect the fuel tank for any leaks or damage. Repair or replace the fuel tank if needed.
  5. Clear Codes: After making the necessary repairs, clear the diagnostic trouble codes from the vehicle's onboard computer to reset the check engine light.

Cost to Fix P0455 2015 GMC Sierra

The typical repair costs for addressing a P0455 code on a 2015 GMC Sierra can vary depending on the specific cause of the issue. In general, the cost of parts for this repair can range from $50 to $200, while labor costs can range from $100 to $300. Overall, the total repair cost for resolving a P0455 code can be estimated to be between $150 and $500. It's important to note that these estimates are rough averages and actual costs may vary based on factors such as location, vehicle make and model, and the specific diagnosis and repair process required. It's recommended to consult with a qualified mechanic or auto repair shop for a more accurate cost estimate based on the individual circumstances of the vehicle.

What does this mean?

Tech Notes for P0455 2015 GMC Sierra

The P0455 code means that the control module has detected a small leak in the Evaporative Emission (EVAP). A loose fuel tank filler cap is the most common cause that will trigger the P0455 code.



There is a factory service bulletin for all the models from 2000 through 2021. The factory states that there are seven critical connections that could likely lead to this DTC being set:

1. Purge tube to purge valve (at intake manifold)

2. Purge tube to chassis EVAP line (at the rear of the engine, near transmission)

3. Chassis EVAP line to canister (at canister)

4. Fuel tank load line to canister (at canister)

5. Vent valve line to vent valve (at vent valve)

6. Fuel tank load line jumper connection (near fuel tank)

7. Fuel tank cap is closed properly (at refuel compartment)

Need more information about the P0455 2015 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 P0455 2015 GMC Sierra Code

1. What does OBDII code P0455 mean for my 2015 GMC Sierra?

- OBDII code P0455 indicates an Evaporative Emission System Large Leak Detected in your vehicle's GMC Sierra.

2. What are common symptoms of the P0455 code in a 2015 GMC Sierra?

- Common symptoms of the P0455 code may include a strong fuel odor, the Check Engine Light being illuminated, and possible issues when refueling.

3. What are the potential causes of the P0455 code in a 2015 GMC Sierra?

- Causes of the P0455 code can include a loose or damaged gas cap, a leak in the evaporative emission system, a faulty purge valve, or a malfunctioning charcoal canister.

4. How can I diagnose the P0455 code in my 2015 GMC Sierra?

- Diagnosing the P0455 code may involve checking the gas cap for tightness, inspecting the EVAP system components for leaks, and using a smoke machine to detect the source of the large leak.

5. What are some repair tips for fixing the P0455 code in a 2015 GMC Sierra?

- Repair tips for the P0455 code may include tightening or replacing the gas cap, repairing or replacing damaged hoses in the EVAP system, testing and replacing the purge valve or charcoal canister if needed.

6. Can I still drive my 2015 GMC Sierra with the P0455 code present?

- It is generally safe to drive your GMC Sierra with the P0455 code, but it is recommended to address the issue promptly to prevent potential fuel economy loss or emissions problems.

7. How much does it cost to repair the P0455 code in a 2015 GMC Sierra?

- The cost to repair the P0455 code can vary depending on the specific cause of the issue, but it may range from around $100 for a simple fix like a gas cap replacement to several hundred dollars for more extensive repairs.

8. Will the P0455 code reset itself after repairs are made on a 2015 GMC Sierra?

- Once repairs are made to address the P0455 code in your GMC Sierra, you may need to clear the code using an OBDII scanner to reset the Check Engine Light and ensure the issue has been resolved.

9. How common is the P0455 code in a 2015 GMC Sierra?

- The P0455 code, indicating an Evaporative Emission System Large Leak Detected, is a relatively common OBDII code in vehicles like the 2015 GMC Sierra due to issues with the evaporative emission control system.

10. Can I fix the P0455 code in my 2015 GMC Sierra myself, or should I take it to a mechanic?

- Depending on your automotive repair skills and the specific cause of the P0455 code, you may be able to fix it yourself by addressing common issues like a loose gas cap. For more complex problems, it's advisable to consult a mechanic for proper diagnosis and repair.

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