4WD Control System Description

4WD Control System Description

Transfer Shift Control

The 4WD control module controls the transfer shift actuator based on the signal from the transfer switch so that the transfer is shifted to the selected position (4H, 4H-lock, N or 4L-lock). (Shifting to the N position requires that the switch to "square" position (1) keep it there for about 10 seconds then turn it to "N" position.)

The transfer actuator consists of the actuator motor and the actuator motor position switch. The 4WD control module detects the position of the actuator motor using the position switch and controls the actuator motor running / stopping operation.

Also, the 4L/N switch and center differential lock switch that detect the each position of the High / Low shift fork and the differential lock shift fork are installed the transfer assembly. The 4WD control module detects the transfer actual shift position (4H, 4H-lock, N or 4L-lock) by the signals from the 4L/N switch and center differential lock switch as follows.





Relationship of transfer shift position and switches





When the transfer shift actuator motor position detected by motor position switch and transfer actual shift position detected by the above-mentioned switches match, the 4WD control module judges that the transfer shifting is complete.

Retry Control

When 4WD control module cannot judge the shifting to the target position, it commands to retry the shifting up to 3 times. If retry shifting is not possible, previous shift position is restored and notify failure of the shifting with the indicator and buzzer.

Indicator And Buzzer Operation

The 4WD control module output operation signal of the differential lock indicator, 4L indicator, N indicator and the buzzer to Combination Meter. Indicators and buzzer as follows in order to inform what state the transfer control system is.

NOTE:

Three indicators with asterisk (*) in this table blink at the same time when detecting DTC(s) other than DTC C1237 / C1238 / C1243.






Information Display Operation

The 4WD control module sends a signal to the combination meter through CAN communication the instructions displayed on the information display urging vehicle driver to exercise caution and perform required operations.