P2420

3UZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P2420: Evaporative Emission Pressure Switching Valve Stuck OFF

DTC P2420 - Evaporative Emission Pressure Switching Valve Stuck OFF

DTC SUMMARY





HINT: The vent valve is built into the canister pump module.

DESCRIPTION

The description can be found in the EVAP (Evaporative Emission) System EVAP System.

INSPECTION PROCEDURE

Refer to the EVAP system EVAP System.

MONITOR DESCRIPTION

5 hours* after the ignition switch is turned OFF, the leak detection pump creates negative pressure (vacuum) in the EVAP system. The ECM monitors for leaks and actuator malfunctions based on the EVAP pressure.
HINT: *: If the engine coolant temperature is not below 35°C (95°F) 5 hours after the ignition switch is turned OFF, the monitor check starts 2 hours later. If it is still not below 35°C (95°F) 7 hours after the ignition switch is turned OFF, the monitor check starts 2.5 hours later.





*: If only a small amount of fuel is in the fuel tank, it takes longer for the EVAP pressure to stabilize.





P2420: Vent valve stuck open (vent)
In operation C, the vent valve turns ON (closes) and the EVAP system pressure is then measured by the ECM, using the canister pressure sensor, to conduct an EVAP leak check. If the pressure does not increase when the vent valve is open, the ECM interprets this as the vent valve being stuck open. The ECM illuminates the MIL and sets the DTC.





MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS





1. Key-off monitor sequence 1 to 8

1. Atmospheric pressure measurement





2. First reference pressure measurement





3. Vent valve stuck closed check





4. Vacuum introduction





5. Purge VSV stuck closed check





6. Second reference pressure measurement





7. Leak check





8. Atmospheric pressure measurement





TYPICAL MALFUNCTION THRESHOLDS





MONITOR RESULT

Refer to the CHECKING MONITOR STATUS Mode 6 Data.