Transfer Case Shift Control Switch

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.

Fig 1: Identifying Transfer Case Shift Control Switch

Courtesy of GENERAL MOTORS CORP.

The BW 4482 transfer case features a 3-button shift control switch located on the instrument panel. When the vehicle has the ignition key in the RUN position, the transfer case shift control module starts monitoring the transfer case shift control switch to determine if the driver desires a new mode/range position. At a single press of the transfer case shift control switch, the lamp of the new desired position will begin flashing to inform the driver that the transfer case shift control module has received the request for a new mode/range position. The lamp will continue to flash until all shifting criteria have been met and the new mode/range position has been reached, or has been engaged. Once the new mode/range position is fully active, the switch indicator lamp for the new position will remain ON constantly.

In addition, the switch includes a VSES request button which sends a voltage signal to the transfer case shift control module. The transfer case shift control module in turn sends a request via the class 2 data bus to the ABS control module which controls the VSES system.

During normal driving situations, the transfer case operates in the 4HI mode. When the 4HI mode is selected, the transfer case shift control module sends 12 volts to an electrical motor, which is the transfer case encoder motor. This motor rotates the transfer case shift detent lever shaft which moves the shift forks and range sleeve to obtain different modes/ranges.

The BW 4482 transfer case has the added feature of also providing the driver with 2 selectable mode/range positions and a VSES request button:

4HI - Full Time 4 Wheel Drive
4LO - 4 Wheel Drive Low Locked
VSES - Vehicle Stability Enhancement System

The transfer case will not allow a shift into or out of 4LO unless the following criteria has been met:

The engine is running.
The automatic transmission is in Neutral.
The vehicle speed is below 5 km/h (3 mph).

This transfer case also has a Neutral position. A shift to the Neutral position allows the vehicle to be towed without the transmission output shaft rotating. Refer to the Owners Manual for instructions for proper towing of the vehicle.

Neutral position may be obtained only if the following criteria have been met:

The ignition switch is ON.
The automatic transmission is in Neutral.
The vehicle speed is below 5 km/h (3 mph).
The transfer case is in the 4HI mode.

Once these conditions have been met, press and hold both the 4HI and 4LO Lock buttons for 10 seconds. When the system completes the shift to neutral, the red neutral indicator will illuminate.