COMPONENT DESCRIPTION
The variable valve lift system optimizes the intake valve lift by switching between the low lift cam and the high lift cam according to the engine speed. The amount of intake valve lift is varied by controlling the oil switching solenoid valve duty according to signals from the ECM.
Scheme 186
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 187
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 188
| Condition of pressure | Flow |
|---|---|
| A < B (solenoid OFF) | B --> C |
| B < C (solenoid OFF) | C --> B |
| Solenoid ON | B <-- --> C |
PRESSURE CONDITION SPECIFICATION CHART
When A < B (solenoid OFF)
Scheme 189
When B < C (solenoid OFF)
Scheme 190
When Solenoid is ON
Scheme 191
Drain valve
Drain valve controls the ambient air to be introduced to the canister.
Scheme 192
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 and TCM 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
The barometric pressure sensor is built into the ECM.
The barometric pressure sensor is built into the ECM.
The barometric pressure sensor is built into the ECM.