Theory Of Operation
The Transfer Case Selector (4WD-AUTO) Switch is not a serviceable component of the Transfer Case Shifter assembly. There are 2 circuits between the Transfer Case Selector Switch and the DTCM:
- 4WD-Auto Request Signal
- Ground
When the Transfer Case shifter is put into the 4WD-AUTO position, the Transfer Case Selector Switch located on the Transfer Case Shifter assembly completes a circuit to ground through the 4WD-Auto Request Signal circuit. The DTCM then monitors the ABS Wheel Speeds that are received over the CAN. When wheel slippage is detected, the DTCM modulates the front drive clutch to send torque to the front axle as needed.