P2450

DTC P2450 Fuel Vapor-containment Valve Stuck Open
DTC P2451 Fuel Vapor-containment Valve Stuck Close

DTC SUMMARY

DTC Detection Condition:

DESCRIPTION
While the engine is running, if a predetermined condition (closed loop, etc.) is met, the EVAP VSV is opened by the ECM (Included in HV control ECU) and stored fuel vapors in the canister are purged to the intake manifold. The ECM will change the duty cycle ratio of the EVAP VSV to control purge flow volume. Purge flow volume is also determined by the intake manifold pressure. Atmospheric pressure is allowed into 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.

Key-off monitor
This monitoring system checks for pump module malfunctions and leaks from the EVAP and closed tank systems. Be sure to leave the vehicle for at least 5 hours to sufficiently cool the fuel and stabilize fuel tank pressure. This makes EVAP system monitoring more accurate.

HINT: If the engine coolant temperature is 35°C or more, 5 hours after the ignition switch has been turned off, the ECM (Included in HV control ECU) will begin performing a monitor check after another 2 hours. If the engine coolant temperature is still 35°C or more, 7 hours after the ignition switch has been turned off, the ECM will begin performing a monitor check after another 2.5 hours.

There are two methods for monitoring the EVAP system.
1. If the fuel tank pressure is higher or lower than the atmospheric pressure, the system determines that there are no leaks in the closed tank system and the system will check for leaks from the piping and canister between the EVAP VSV and pump module.(Method A)
2. If the fuel tank pressure is almost the same as the atmospheric pressure, vacuum pressure will enter the fuel tank and the system will check for leaks from the fuel tank after checking for leaks from the canister.(Method B)

Purge flow monitor
If EVAP system pressure change is less than 7.5 mmHg (1 kPa) when the engine is running and the EVAP VSV is turned ON (closed), the ECM (Included in HV control ECU) determines that the purge flow is insufficient.

MONITOR DESCRIPTION
1. P2450: Fuel vapor-containment valve (FVCV) stuck open
During sequence C, the vacuum pump creates vacuum pressure in the EVAP system. If the pressure in the fuel tank drops, the ECM (Included in HV control ECU) determines that the tank close valve is stuck open. The ECM then illuminates the MIL and sets the DTC. (This DTC is set according to 2trip detection logic.)

2. P2451: Fuel vapor-containment valve (FVCV) stuck closed (vent)
During sequence G, the tank close 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 tank close valve is stuck closed. The ECM then illuminates the MIL and sets the DTC. (This DTC is set according to 2trip 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 (Included in HV control ECU) determines that the tank close valve is stuck closed. The ECM then illuminates the MIL and sets the DTC. (This DTC is set according to 2trip detection logic.)

Monitor Strategy:

Typical Enabling Conditions (Part 1):

Typical Enabling Conditions (Part 2):

Typical Malfunction Thresholds:

MONITOR RESULT

Refer to CHECKING MONITOR STATUS. Mode 6 Data

The test value and test limit information are described as shown in the following table. Check the monitor result and test values after performing the monitor drive pattern (refer to "Confirmation Monitor").
- MID (Monitor Identification Data) is assigned to each emissions-related component.
- TID (Test Identification Data) is assigned to each test value.
- Scaling is used to calculate the test value indicated on generic OBD-II scan tools.