Control Module: Description and Operation

Operation

The TCCM receives inputs signals, processes the signal information, develops outputs signals, and sends the outputs signals to control the shifting of the transfer case. The TCCM receives input signals from the following sources:

- Transfer case shift select buttons.

- NSBU switch on vehicles with automatic transmissions.

- Clutch safety switch on vehicles with manual transmissions.

- Vehicle speed sensor calibrator module.

- Encoder/motor range and mode feedback signals.

- Diagnostic enable.

- Front axle mechanical status signal.

After processing the received information, the TCCM develops and outputs signals to the following:

- Motor/encoder.

- Select illumination switch circuit.

- Diagnostic trouble codes to it's self.

To ensure the electronic shift system is operating properly, the transfer case control module (TCCM) continually performs diagnostics checks on itself and other parts of the electronic shift system when the ignition switch is in the run position. The following are different types of system checks that the TCCM continually performs.