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P0456 Evaporative Emission System-Leak detected (very small leak)

AutoHex Online Help: Hyundai GENESIS(BH) 2012
General Description

The evaporative emission control system prevents hydrocarbon (HC) vapors from the fuel tank from escaping into the atmosphere where they could form photochemical smog. Gasoline vapors are collected in the charcoal canister. The ECM controls the Purge Control Solenoid Valve (PCSV) to purge any collected vapors from the canister back to the engine for combustion. This valve is actuated by the purge control signal from the ECM and controls fuel vapor flow from the canister to the intake manifold.

DTC Description

Checking output signals from fuel tank pressure sensor under evap.system test, if fuel tank's vacuum decay slope is higher than prescribed threshold, ECM sets P0456.



DTC Detecting Condition

Item

Detecting Condition

Possible cause

DTC Strategy

Monitor the vacuum decay slope

Leakage in each hose/fuel filler pipe

Leakage in CCV/ Canister/ Fuel tank /Fuel Filler Cap

Enable Conditions

Canister Close Valve close

Canister Purge Valve close

Time after engine start > 560 sec

4?(39.2?) < ECT at start temp < 50?(122?)

ECT at start – IAT < 9.8?(49.64?)

0?(32?) < IAT temp < 42?(107.6?)

BARO > 74.5 kPa

15% < Fuel level < 85%

Duration of tank ventilation > 10 sec

Fuel System Status Closed loop

Accel. Pedal = 0%

Disable conditions : P0300 ~ P0308

Threshold value

FTP gradient > 0.038~0.06 kPa/sec

Diagnosis Time

-

MIL On Condition

2 driving cycle