Circuit Description

EVAP emission system is tested with on-board diagnostics by apply pressure (vacuum) to system and monitoring pressure decay. PCM monitors vacuum level through the fuel tank pressure sensor. A leak is detected my monitoring for a decrease in vacuum level over a calibrated period of time, while keeping all variables constant.

DTC will set when:

• BARO greater than 75 kPa.
• ECT and IAT between 39-86°F (4-30°C) at engine start-up.
• IAT not greater than 3°F (1.5°C) of ECT at start-up.
• Throttle angle between 7-35 percent.
• Vehicle speed less than 70 MPH.
• EVAP purge solenoid enabled.
• Fuel tank level between 15-85 percent.
• DTCs P0105, P0107, P0108, P0112, P0113, P0117, P0118, P0122, P0123, P0125, P0131, P0132, P0133, P0134, P0452, P0453, P0502, P0503, P0601, P0602, P1133 and P1621 are not set.
• Vacuum decay is greater than calibrated amount during test.