Circuit Description
WARNING: This page is about a different car, the 2005 GMC Yukon XL, 2005 GMC Yukon, 2005 Chevrolet Tahoe, 2005 Chevrolet Suburban, and 2005 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
The range/mode switch circuit consists of 5 modes. The transfer case shift control module supplies 5 volts to the switch through the 5-volt reference circuit. The current travel through the resistor of the currently active mode. The current is then returned to the transfer case shift control module through the switch signal circuit.
The transfer case shift control module constantly monitors this signal voltage to determine the condition of the mode switch circuit.
When each of the modes are selected they complete a circuit through their own specific resistor. The transfer case shift control module continuously monitors the switch input to determine whether the Neutral, AWD, 2HI, 4HI, or 4LO mode was selected by the driver.