EVAP Emission Control System Leak Detected (Fuel Cap)
Fuel cap is either loose, damaged, or the system is leaking.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The vehicle's computer can’t detect pressure or vacuum in the fuel system because it thinks the fuel cap isn’t sealing properly, which could mean it's loose or damaged.
What the computer is actually seeing
The engine control module (ECM) is monitoring for fuel vapor leaks; if the pressure drops below a certain level or if it doesn't build up pressure, it triggers this code.
What a healthy reading looks like
Normal pressure readings in the EVAP system should be between 0-4 inHg during the self-test. A significant drop may indicate a leak or an issue with the fuel cap.
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 11. Start with a visual inspection of the fuel cap. Ensure it is tight and in good condition. If it's damaged, replace it and see if the code clears.
- 22. Check the condition of the EVAP hoses for cracks or leaks. A simple shake test can help identify leaks. Repair or replace any damaged hoses.
- 33. Use a scan tool to monitor the fuel tank pressure sensor. If the readings are outside expected values, it may need replacement.
- 44. Inspect the EVAP purge valve for proper operation. Apply voltage to it and see if it opens. Replace if it doesn’t function correctly.
Common causes
- Loose or damaged fuel cap
- Cracked EVAP hoses
- Faulty EVAP purge valve
- Faulty fuel tank pressure sensor
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
Yes, it is drivable, but address it soon to avoid potential emissions problems.
Will this code come back after clearing it?
If the underlying issue isn't fixed, the code will likely return after a short drive cycle.
Why does this code sometimes pair with other codes?
This code may show up alongside other EVAP system codes because they may share common components or issues.
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