P0440 Evaporative emission system
- System
- Powertrain - engine and transmission
What P0440 means
"Evaporative emission control system" names the system that keeps fuel vapour from leaving the tank, and the name stops there: it identifies the system the code is filed against without naming a measurement or a direction. The codes around it are the specific ones, P0442 and P0455 stating a leak by size and P0446 naming the venting side.
This is a standard code. It means the same thing on every make of vehicle.
What the program shows for P0440
Evap purge and Fuel level are on the Dashboard, and the Full scan's on-board self-tests report the EVAP leak, EVAP purge flow and EVAP purge valve results with the car's own limits. The Inspection screen says whether the fuel vapour system monitor has finished, which for this system often needs a particular fuel level and several drives.
The Dashboard shows Commanded EGR, EGR error, Evap purge, Catalyst temp, O2 sensor (rear), Fuel level and Coolant temp. The Full scan's On-board self-tests list the Catalyst bank, EGR / VVT bank, EVAP leak, EVAP purge flow, EVAP purge valve and Secondary air results as PASS, FAIL or NO RESULT against the car's own limits, and the Inspection screen shows whether the Catalytic converter, Fuel vapour system, Exhaust gas recirculation and Secondary air injection monitors are done or still running. Clear codes warns that clearing resets those monitors.
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