Operation

Transfer Box

OPERATION

Power Distribution
Feed from the positive battery terminal (C0192) is supplied to fusible link 3E and fusible link 11E (C0632) on an R wire. Both are located in the Battery Junction Box (BJB). Fusible link 3E (C0570) provides a constant battery feed to the transfer box control module (C1854) on a PU wire. The transfer box control module (C1854) is provided a ground path on a B wire.

Fusible link 11E (C0570) is connected to the ignition switch (C0028) by an N wire. When the ignition switch is in the 'ignition' position, current flows across the switch (C0028) to fuse 24P and fuse 69P of the CJB (C0582) on a Y wire. Fuse 24P (C0583) provides an ignition feed to the transfer box control module (C1854) and the range change selection switch (C0700) on an R wire.

Range Change Selection Switch
The range change selection switch (C0700) is provided an ignition feed from fuse 24P of the CJB (C0583) on an R wire. When the switch is pushed forward to the 'Hi' position, current flows across the switch to the transfer box control module (C1319) on a W wire. If the switch is pulled back to the 'Lo' position, current flows across the switch to the transfer box control module on an R wire.

When a range change request is made, the transfer box control module will illuminate the appropriate indicator. If 'Hi' is selected, the transfer box control module (C1319) provides a ground path for the high range indicator (C0700) on a U wire. If 'Lo' is selected, the transfer box control module (C1319) provides a ground path for the low range indicator (C0700) on a G wire.

High Low Range Position Sensor
The transfer box control module is able to determine which range the transfer box is in via the high/low range position sensor. The control module (C1855) provides a feed to the sensor (C2169) on a UR and a ground path via an RY wire. The sensor provides a Pulse Width Modulated (PWM) signal to the control module on an R wire. This signal enables the control module to determine if the transfer box is in high or low range.

Transfer Box Motor Assembly
The transfer box motor assembly performs two functions. It controls the amount of slip allowed through the center differential via the clutch, and performs the change between high and low range. These two functions cannot be carried out at the same time. To switch between the two functions, a solenoid is used.

Mode Selector Solenoid
The mode selector solenoid is mounted on the transfer box casing and is used to switch motor usage between center differential slip control and range change control. The control module (C1855) provides a feed to the solenoid on a G wire, and a ground path via an S wire. When the solenoid is energised the motor will control center differential slip. To enable the motor to carry out a range change, the control module will de-energise the solenoid.

Motor
Two hall effect sensors are located within the motor. The transfer box control module (C1855) provides a feed to both sensors (C2167) on a UR wire. A ground path is provided for the sensors via the control module on a RY wire.

Hall sensor 'A' (C2167) provides a signal to the control module (C1855) on a GR wire. This signal enables the control module to determine the direction in which the motor is running. Hall sensor 'B' provides a signal to the control module on a GY wire. This signal enables the control module to determine the position of the motor (the amount of pressure it is applying to the center differential clutch plates).

The motor applies pressure to the center differential clutch plates to control the amount of slip. To apply pressure, the transfer box control module (C1855) provides a feed to the motor (C2167) on an N wire. A ground path is provided via the control module on an R wire. To release pressure the feed to the motor is reversed. The control module provides a feed on an R wire, and a ground path via an N wire.

Gearbox Secondary Speed Sensor
If vehicle speed is above pre-determined limits, the transfer box control module will not allow changes between high and low ratio. The control module monitors vehicle speed via the gearbox secondary speed hall effect sensor.

The control module (C1855) provides a feed to the sensor (C1561) on a UR wire, and a ground path via an RY wire. By measuring the frequency of the pulses returned on a Y wire, the control unit can determine vehicle speed.

Gear Lever Position Sensor - Manual Transmission Only
The transfer box control module monitors which gear has been selected via the gear lever position sensor. The sensor is mounted on top of the transmission housing and monitors movement of the selector shaft. The sensor (C0675) is provided a feed by the control module (C1855) on a UR wire. A ground path for the sensor, is provided via the control module on an RY wire.

The sensor provides two signals back to the control module to enable it to determine the position of the selector shaft. A left and right movement signal (X axis) is provided to the control module on a UR wire. A backwards and forwards movement signal (Y axis) is provided to the control module on an O wire.