DTC P0442 Evaporative Emission (EVAP) System Small Leak Detected

Download DTC P0442 Evaporative Emission (EVAP) System Small Leak Detected Refer to Engine Controls Routing Diagram, EVAP Control System Overview . System Description This DTC tests the evaporative emission (EVAP) system for a small leak. The control module monitors the fuel tank pressure (FTP) sensor signal to determine the vacuum decay rate. At an appropriate time, the control module turns the EVAP canister purge valve ON and the EVAP vent valve ON. This allows the engine to draw a vacuum on the EVAP system. At a calibrated time, or vacuum level, the control module turns the EVAP canister purge valve OFF, sealing the system, and monitors the FTP sensor input in order to determine the EVAP system vacuum decay. If the control module detects a leak larger than a calibrated amount, this DTC sets. The following table illustrates the relationship between the ON and OFF states, and the Open or Closed states of the EVAP canister purge and vent valves. Conditions for Running the DTC z DTCs P0107, P0108, P0110, P0112, P0113, P0115, P0116, P0117, P0118, P0121, P0122, P0123, P0125, P0440, P0443, P0449, P0452, P0453, P1106, P1107, P1111, P1112, P1114, P1115, P1121, or P1122 are not set. z The system voltage is between 10-18 volts. z The startup engine coolant temperature (ECT) is between 4-30°C (39-86°F) , but the startup ECT is not more than 8°C (14°F) more than the startup intake air temperature (IAT). z The startup IAT is between 4-30°C (39-86°F), but the startup IAT not more than 3°C (7°F) more than the startup ECT temperature. z The fuel tank level is between 20-85 percent. z The barometric pressure (BARO) is more than 75 kPa. z The vehicle speed sensor (VSS) is less than 121 km/h (75 mph). Conditions for Setting the DTC The EVAP system can achieve vacuum, but a vacuum decay is detected during the diagnostic test. Action Taken When the DTC Sets z The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails. z The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records. Conditions for Clearing the MIL/DTC z The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the Control Module Command EVAP Canister Purge Valve EVAP Canister Vent Valve ON Open Closed OFF Closed Open
diagnostic runs and does not fail. z A current DTC, Last Test Failed, clears when the diagnostic runs and passes. z A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic. z Clear the MIL and the DTC with a scan tool.