Accessory Switch

WARNING: This page is about a different car, the 2007 Isuzu i-370, 2007 GMC Canyon, and 2007 Chevrolet Colorado. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Accessory Switch

Courtesy of GENERAL MOTORS CORP.

The Isuzu T150 transfer case features a 3-button accessory 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 accessory switch to determine if the driver desires a new mode/range position. At a single press of the accessory 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.

During normal driving situations, the transfer case operates in the 2HI mode. When the 2HI 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 Isuzu T150 transfer case has the added feature of also providing the driver with 2 selectable mode/range positions:

The transfer case does not allow a shift into or out of 4LO unless the following criteria is met:

The engine is running.
The automatic transmission is in NEUTRAL.
The vehicle speed is less than 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 Owner's Manual for instructions for proper towing of the vehicle.

NEUTRAL position is obtained only if the following criteria is met:

The ignition is ON.
The automatic transmission is in NEUTRAL.
The vehicle speed is less than 5 km/h (3 mph).
The transfer case is in the 2HI mode.

Once these conditions have been met, press and hold both the 2HI and 4LO Lock buttons for 10 seconds. When the system completes the shift to NEUTRAL, the red NEUTRAL indicator will illuminate.