DTC P04E0: General Description

Courtesy of HONDA, U.S.A., INC.

Courtesy of HONDA, U.S.A., INC.

Negative pressure is created in the evaporative emission (EVAP) system by reducing the pressure in the EVAP leak check module. When the EVAP canister purge valve is opened under that state, the air is sucked in through the intake manifold to cause the EVAP system pressure to be recovered to barometric pressure. The powertrain control module (PCM) detects a malfunction and stores a DTC when the prescribed change in the pressure toward positive pressure has not occurred after a given period of time of opening the EVAP canister purge valve.