| Component | Function |
|---|---|
| 4WD switch | Refer to 4WD Control System Component Functional Description . |
| 4WD control module | Refer to 4WD Control System Component Functional Description . |
| VSV1 | VSV1 operates according to the signal from the 4WD control module. When it is activated, the port opens and vacuum is applied through the vacuum circuit to unlock to the slide gear in the air locking hub. As a result, the air locking hubs are free. |
| VSV2 | VSV2 operates according to the signal from the 4WD control module. When it is activated, the port opens and vacuum is applied through the vacuum circuit to lock to the slide gear in the air locking hub. As a result, the air locking hubs are locked. |
| Vacuum switch | When the 4WD control module receives the “ON” signal from the 4WD switch, the vacuum is applied through VSV2 to the vacuum switch. The vacuum switch turn on when it detect vacuum exceeding –36 kPa (–5.22 psi). |
| 4WD indicator | Refer to 4WD Control System Component Functional Description . |
| 4WD low indicator | Refer to 4WD Control System Component Functional Description . |
|
Vacuum pump
(K9K engine model) |
This vacuum pump is installed in the generator, and driven with the engine through the generator drive belt. 4WD control system and brake booster operate by the vacuum made with the vacuum pump. |
| Vacuum control valve (K9K engine model) |
The vacuum made with the vacuum pump is adjusted to appropriate vacuum.
As a result, 4WD control system is prevented being damaged by excessive vacuum. |