DTC Parameters

• EVAP purge solenoid is commanded OFF.
• EVAP vent solenoid is commanded ON.
• Engine is at idle.
• Vehicle speed is zero MPH.
• Engine load is less than 35 percent.
• MAP is less than 40 kPa.
• Battery voltage is more than 11 volts.
• ECT at start-up is 46-167°F (8-75°C).
• IAT is 46-122°F (8-50°C).
• Long term fuel cells not cleared (if cleared, engine must run longer than 16 minutes 45 seconds).
• Fuel level is 1.6-12.7 gallons.
• No ECT, EVAP purge solenoid, EVAP vent solenoid, fuel tank pressure, idle speed HO2S, throttle actuator, TP sensor or vehicle speed DTCs have been set.

DTC sets if the vacuum decay is greater than 0.35 fuel tank pressure sensor volts (change from -3.21 in. H2O to higher than -1.61 in. H20) over a 10.5 second period during phase "E" of the EVAP diagnostic system test indicating a small EVAP leak. Condition exists for the entire phase "E" of 10.5 seconds.

DTC P0442 diagnostic runs once during phase "E" of the EVAP diagnostic test once per ignition cycle. If the P0442 diagnostic fails, the ECM will rerun the EVAP diagnostic test from the beginning and must fail the P0442 diagnostic again to set the DTC. If an EVAP diagnostic test is aborted due to changing enable criteria, the ECM will run the entire EVAP diagnostic test up to three times per ignition cycle.