COMPONENT DESCRIPTION
Pressure control solenoid valve
PCV controls the fuel tank pressure to be equal to the atmospheric air pressure. Normally, the solenoid is set to OFF. The valve opens and closes mechanically in accordance with the pressure difference between tank and atmospheric air, or tank and canister.
The valve is forcibly opened by setting the solenoid to ON at the time of diagnosis.
Scheme 1
Valve Operation and Air Flow
In the figure below, divided by the diaphragm, the part above X is charged with atmospheric air pressure, and the part below X is charged with tank pressure. Also, the part above Y is charged with tank pressure, and the part below Y is charged with canister pressure.
If the atmospheric air pressure port is A, tank pressure port is B, and canister pressure port is C, the air flows according to pressure difference from each port as shown in the table below.
Scheme 2
| Condition of pressure | Flow |
|---|---|
| A < B (solenoid OFF) | B --> C |
| B < C (solenoid OFF) | C --> B |
| Solenoid ON | B <-- --> C |
PRESSURE CONDITION REFERENCE
When A < B (solenoid OFF)
Scheme 3
When B < C (solenoid OFF)
Scheme 4
When Solenoid is ON
Scheme 5
Drain valve
Drain valve controls the ambient air to be introduced to the canister.
Scheme 6
Vehicle speed signals are taken in to the ABS control module and hydraulic control unit, and normal/erroneous data of the ABS wheel speed sensor is received by CAN communication from the ABS control module and hydraulic control unit.
ECM, VDC CM and DCCD CM are connected by high speed CAN.
(Common Specifications)
CAN Protocol 2.0 B (Active)
Frame Format: 11 Bit ID Frame (Standard Frame)
(High speed CAN)
Conforms to ISO11898
Communication Speed: 500 kbps