Monitor Description

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When 5 hours have elapsed after the ignition switch is turned OFF, the electric vacuum pump creates negative pressure (vacuum) in EVAP system. Then ECM monitors for leaks and actuator malfunctions based on EVAP pressure.

Fig 1: Monitor Description Chart

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Fig 2: EVAP Leak And Pressure Measurement Checking System Diagram (A-D)

P2419: Vent valve stuck ON
For order C, the vacuum pump creates negative pressure (vacuum) through 0.02 inch orifice and pressure is measured. The ECM determines that the vent valve is stuck ON (closed) if: 1) the pressure is higher than -7.5 mmHg (-1 kPa) or lower than -33.75 mmHg (-4.5 kPa); and 2) the EVAP system pressure does not stabilize for a duration of 60 seconds. The ECM illuminates the MIL and sets a DTC (2-trip detection logic).

Fig 3: EVAP Pressure Leak Graph (Vent Valve Stuck ON)
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P2420: Vent valve stuck OFF
If difference in EVAP pressure in EVAP system pressure for order C and D is small and does not increase more than 2.25 mmHg (0.3 kPa) within 10 seconds of changing the vent valve from OFF (vent) to ON (closed), the ECM determines that the vent valve is stuck OFF (vent).

Fig 4: EVAP Pressure Leak Graph (Vent Valve Stuck OFF)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002