Transfer Box Control Module: Notes

The transfer box control module controls the high/low 'shift-on-the-move' actuation and the multi-plate clutch actuation. The control module is located in the E-box, next to the Engine Control Module (ECM).

Courtesy of JAGUAR CARS, INC.

The control module is connected to the Controller Area Network (CAN) bus and controls transfer box operation using CAN messages from other control modules on the network.

The control module memorizes the position of the transfer box motor when the ignition is switched off.

The transfer box control module uses the same actuator to control both range change function and application of center differential locking torque. The module uses position feed back from the actuator to provide smooth range changing capability and graduated application of locking torque appropriate for the current driving conditions. Range change can be carried out while moving providing the transmission is in neutral and the vehicle is below the speed necessary for the requested range change.

The control module uses 3 connectors for all inputs and outputs. It receives a permanent power supply via a 30A fuse located in the Battery Junction Box (BJB), and an ignition supply via fuse 33 in the Generic Electronic Module (GEM).

The control module uses a series of programmed shift maps to control the synchronization speed and ensure that a maximum shift time of approximately 1 second is achieved.

If the control module is replaced, the Land Rover approved diagnostic system must be connected to the vehicle and the transfer box control module self-calibration procedure must be performed. This procedure must also be performed if the transfer box motor assembly is replaced.