Up to 08/2009

2GR-FXE ENGINE CONTROL: SFI SYSTEM: P2450,P2451: Fuel Vapor-containment Valve Stuck Open
P2451 - Fuel Vapor-containment Valve Stuck Close

DTC SUMMARY

DESCRIPTION

While the engine is running, if predetermined conditions (closed loop, etc.) are met, the purge VSV is opened by the ECM and stored fuel vapors in the canister are purged to the intake manifold. The ECM will change the duty cycle ratio of the purge VSV to control purge flow volume.

Purge flow volume is also determined by the intake manifold pressure. Atmospheric pressure is allowed to enter the canister through the vent valve to ensure that purge flow is maintained when negative pressure (vacuum) is applied to the canister.

The ECM monitors the condition of both the key-off monitor and purge flow monitor to ensure proper operation of the EVAP system.

MONITOR DESCRIPTION

- P2450: Fuel vapor-containment valve (FVCV) stuck open

- During sequence C, the vacuum pump creates vacuum in the EVAP system. If the pressure in the fuel tank drops, the ECM determines that the fuel vapor-containment valve is stuck open. The ECM then illuminates the MIL and sets the DTC. (This DTC is set according to 2 trip detection logic.)

- P2451: Fuel vapor-containment valve (FVCV) stuck closed (vent)

- During sequence G, the fuel vapor-containment valve opens to allow vacuum pressure generated by the vacuum pump into the fuel tank. If the pressure in the fuel tank does not drop, the ECM determines that the fuel vapor-containment valve is stuck closed. The ECM then illuminates the MIL and sets the DTC. (This DTC is set according to 2 trip detection logic.)

- During sequence I, the tank close valve opens to allow atmospheric pressure into the fuel tank. If there is no change in fuel tank pressure, the ECM determines that the fuel vapor-containment valve is stuck closed. The ECM then illuminates the MIL and sets the DTC. (This DTC is set according to 2 trip detection logic.)