Evaporative Emission System Incorrect Purge Flow
There's an issue with the evaporative emission control system's purge flow.
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 seeing too much or too little air flow in the charcoal canister system, which can lead to fuel vapors being stuck in the tank instead of venting out.
What the computer is actually seeing
The engine control module (ECM) monitors the purge flow control valve's operation. It expects specific flow rates when the purge valve is activated. When it detects abnormal flow (either too much or too little) at expected activation points, this code triggers.
What a healthy reading looks like
The purge flow should be between 0.5 to 1.5 L/min when activated. If the flow is outside this range, the code will set.
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. Check for any visible damage to the EVAP hoses and connectors. Repair or replace as necessary. DECISION: If any damaged components are found, fix them before continuing.
- 22. Inspect the gas cap. Ensure it seals properly and is not cracked or missing. DECISION: If cap is faulty, replace it and clear the code.
- 33. Test the purge valve operation. Apply power and ground to the valve; it should click and flow air. DECISION: If the valve doesn't operate, replace it.
- 44. Smoke test the EVAP system to check for leaks. Look for smoke escaping from the system. DECISION: If leaks are found, repair them and clear the code.
- 55. If no leaks and all components are functioning, use a scan tool to perform a drive cycle and monitor EVAP flow during the test. DECISION: If the code returns, suspect a failing ECM or further internal issues.
Common causes
- Clogged charcoal canister
- Faulty purge valve
- Damaged hoses
- Loose or missing gas cap
- Leaking EVAP system components
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
Yes, but it's wise to fix it soon as it can affect fuel efficiency and emissions.
Will this code come back after clearing it?
If the underlying issue isn't fixed, the code will likely return.
Why does this code sometimes pair with other codes?
Related codes indicate interconnected components in the EVAP system; fixing one issues may resolve others.
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