GENERAL INFORMATION

SUPER SELECT 4WD II (SS4 II)

The super select 4WD II has the following features.

The shift actuator is controlled by a switch which works in conjunction with the transfer shift lever in order to change the driving mode. This maintains smoother lever operation and accurate drive mode selection.
A planetary gear type centre differential has been adopted which distributes the traction force to the front and rear output shafts in the proportion of 33% to 67%, to maintain the driving stability which is a main feature of 4WD driving, and also to improve steering performance. Furthermore, the adoption of viscous coupling unit (VCU) makes it possible to distribute the driving force, depending on the road condition, between the ratio of 33% to 50% for the front wheel and 67% to 50% for the rear wheel.
The rear differential lock control unit has been integrated with the transfer ECU. The integrated ECU controls the transfer changeover and the rear differential lock system.

note For structure and operation of the rear differential lock system, refer to GROUP 27.
CAN communication has been adopted for communication with other ECUs in order to decrease the number of wires and improve information transmission. The KWP2000 on CAN (Diagnosis function) has been adopted to achieve global standard high-function diagnosis.

DRIVE METHODS

Transfer select lever position	Drive system	High/low	Centre differential	Road surface conditions
2H	2WD	High	Not operating	When driving on general roads and expressways
4H	Full-time 4WD	High	Operating (with viscous coupling unit differential limit)	When driving on general roads, expressways and slippery roads (better driving stability)
4HLc	Direct 4WD	High	Operating (Lock)	When driving on poor roads, sandy roads and snowy roads
4LLc	Direct 4WD	Low	Operating (Lock)	When greater traction force is required, such as when climbing and descending steep slopes

SYSTEM CONFIGURATION DIAGRAM