P0456 Evaporative emission leak detected, very small leak
- System
- Powertrain - engine and transmission
What P0456 means
"Evaporative emission control system leak detected, very small leak" is the smallest of the three size bands for that pressure test, below the small leak of P0442 and well below the gross leak of P0455. The band is the whole content of the name: it says how much the pressure moved, not where it went.
This is a standard code. It means the same thing on every make of vehicle.
What the program shows for P0456
The Full scan's on-board self-tests report the EVAP leak result against the car's own limits, which is where the band this code names is decided. The Inspection screen says whether the fuel vapour system monitor has completed; a monitor that has not run yet has no result to report.
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.
See how the program shows a code →