Circuit Description

WARNING: This page is about a different car, the 2004 GMC Yukon XL and 2004 GMC Yukon. However, it is still accessible from the selected car via links, so may be relevant.

The mode switch circuit consists of 5 modes. The transfer case shift control module supplies a regulated 5 volts, DC to the switch through the 5-volt regulator circuit. The current travel through the resistor of the currently pressed mode button. 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 while the button is pressed. The transfer case shift control module continuously monitors the switch input to determine whether the Neutral, Traction Control System (TCS), All Wheel Drive (AWD), or 4LO Lock mode was selected by the driver.