Evaporative Emission Control System Leak Detected
Indicates a leak in the evaporative emission control system.
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 computer is saying there's a small leak somewhere in the system that captures fuel vapors, which can happen if a hose is cracked or a seal is worn out.
What the computer is actually seeing
The ECU monitors the pressure in the evaporative system. It expects pressure to remain constant. A drop in pressure indicates a leak. This code means the system detected a leak above the allowable threshold during self-tests.
What a healthy reading looks like
Pressure in the evaporative system should be stable between 0 to 5 inches of water column under normal conditions.
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.
- 1Inspect the gas cap for proper seating and condition; ensure it clicks when closed. If loose, secure it and erase codes. Check if code returns.
- 2Visual inspect all EVAP hoses for cracks or damage; pay attention to connection points.
- 3Perform a smoke test on the EVAP system to locate leaks. If smoke escapes, repair the leak and recheck the system.
- 4Check the operation of the purge valve; it should open when commanded and hold pressure when closed.
Common causes
- Worn or cracked hoses in the EVAP system
- Loose or damaged gas cap
- Faulty charcoal canister
- Clogged or damaged purge or vent valve
Typical repair cost
$$-$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
Yes, but fix it soon to avoid potential emissions issues.
Will the code come back after clearing it?
If the leak isn't fixed, yes, the code will likely return.
Why is this code paired with other codes?
Other codes related to the EVAP system can trigger together when the system has multiple issues or faults.
Working a real vehicle right now?
Let DiagCoach walk you through it live with your specific symptoms, vehicle, and what you've already checked.
Start guided diagnostic →