Purge Flow Malfunction
The system is having trouble with the purge flow from the evaporative emissions 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 not getting the right amount of fuel vapors from the canister to the engine for burning, which can lead to excess emissions.
What the computer is actually seeing
The Engine Control Module (ECM) expects a certain flow rate (usually between 0.1 to 0.5 grams per second) from the purge valve when it opens but measures a significantly lower rate, or no flow at all.
What a healthy reading looks like
Expected purge flow rate is typically between 0.1 to 0.5 grams per second during operation under specific 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.
- 11. Check for engine vacuum leaks around the purge valve and hoses. Repair as necessary.
- 22. Inspect the electrical connector and wiring for the purge valve for damage or corrosion; repair or replace as required.
- 33. Use a scan tool to monitor the purge flow during a vehicle test; compare actual purge flow to expected values (0.1 to 0.5 g/s). If low flow is observed, continue testing.
- 44. If the purge flow is low, perform a smoke test on the EVAP system to check for leaks; repair any leaks found.
- 55. If no leaks are found, and wiring is good, replace the purge valve and retest the system.
Common causes
- Clogged or damaged purge valve
- Blocked hoses or canister
- Faulty fuel tank pressure sensor
- Failed ECM programming or failure
- Vacuum leak in the EVAP system
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code active?
It is generally safe to drive, but emissions may be elevated, and it's best to fix soon.
Will this problem come back after repair?
If underlying issues like leaks are not addressed, the code can return.
Why does this code appear with other codes?
These codes often indicate issues in the same system, like the EVAP system or fuel delivery.
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