General Information

P0442 Evaporative Emission System-Leak detected (small leak)

General Information

General Description

The Evaporative Emission Control System (EVAP) prevents hydrocarbon (HC) vapors in the fuel tank from escaping into the atmosphere where they could form photochemical smog. Gasoline vapors are collected in the charcoal canister. The Purge Control Solenoid Valve (PCSV) is actuated (duty cycled) by the Powertrain Control Module (PCM) to control vapor flow from the canister to the intake manifold.

DTC Description

The Powertrain Control Module (PCM) monitors the output signal from the Fuel Tank Pressure Sensor (FTPS) during the Evaporative Emission Control System (EVAP) vacuum self-test. With vacuum present and both the Purge Control Solenoid Valve (PCSV) and Canister Close Valve (CCV) closed. The PCM monitors the fuel tank's vacuum decay slope. If it decays (leaks) higher (faster) than the prescribed threshold, the PCM sets P0442 and turns on the Malfunction Indication Lamp (MIL).

DTC Detecting Condition