DTC P0456: EVAP Control System Very Small Leak (Negative Pressure Check) Or DTC P1456: EVAP Control System Very Small Leak (Positive Pressure Check): Description

This diagnosis detects very small leaks in the EVAP purge line between the fuel tank and EVAP Canister Purge Volume Control Solenoid Valve (EVAP-CPVCSV) using engine intake manifold vacuum. If ECM detects a very small leak, DTC P0456 or P1456 will set. If ECM detects a small leak, DTC P0442 or P1442 will set.