SsangYong Actyon Sports II. Manual - part 134

07-8

3. SYSTEM LAYOUT

Indicators

▶

4H: 4WD HIGH indicator ON

4L: 4WD LOW indicator ON

2H: Indicator OFF

System failure: 4WD CHECK 

warning lamp ON

4WD mode switch

▶

4H: 4 Wheel drive, high speed

4L: 4 Wheel drive, low speed

2H: 2 Wheel drive

TCCU

Solenoid valve

07-9

3240-01

4. IWE LOCKING HUB SYSTEM

1) Overview

The vacuum locking hub uses the IWE (Integrated Wheel End) system, and in this system, the vacuum 

is generated only within the hub actuator.

It is structured to transmit power to the front section after the actuator hub is engaged following the 

release of vacuum from the drive shaft end gear and the hub end gear

Locking hub actuator

Locking hub actuator

Vacuum 

solenoid valve 

for IWE

Vacuum 

pump

Booster

Electric 

signal

To atmosphere

TCCU

Operating Process

Vacuum generation process in front hub actuator

Hub actuator (FR)

Hub actuator (FL)

Vacuum pump

TCCU 

to atmosphere 

to atmosphere

Vacuum solenoid valve

4WD mode 

switch

07-10

2) Vacuum System Related to 4WD

During 2WD mode, the vacuum 

pressure from vacuum pump is 

continuously transmitted to the 

locking hub system.

This vacuum pressure pulls in the 

locking hub actuator so that it will 

not be engaged with the front end 

hub gear.

22WD (applying vacuum pressure to hub 

actuator) The vacuum pressure pulls in the 

locking hub actuator so that it will not be 

engaged with the front end hub gear.

The vacuum pressure is released from the 

hub actuator. At this time, the front hub end 

gear is engaged.

tmosphere 

(in 4WD 

mode)

Hub actuator (LH)

Hub actuator (RH)

In 4WD mode, the TCCU blocks the transferring of 

vacuum pressure from vacuum pump to locking hub 

by supplying the power to solenoid valve.

07-11

3240-01

5. POWER FLOW

Switching 2H, 4H → 4L

Vacuum solenoid

Locking hub operation

(Released internal vacuum)

Front propeller shaft

TCCU

Front axle

Front wheel

Rear propeller shaft

Rear axle

Rear wheel

Transfer case