(4H) Operation

(4H) provides mechanically locked four-wheel drive power to both the front and rear wheels for use in off-road or winter conditions such as deep snow, sand or mud. This mode is not for use on dry pavement. Shifts from (2H) to (4H) can be made at any speed.

Shifts from (2H) to (4H) can be made at any speed. When performing this shift, release the accelerator pedal prior to the shift and wait until the Shift in Progress message disappears in the IPC before accelerating. This improves the shift performance as the transfer case and front axle disconnect actuator engage. In (4H):

• The ATCM sends a (4H) mode status to the AWD module via the GWM.
• The front axle disconnect actuator is connected.
• The shift motor is positioned:
  • The range fork and reduction sleeve connect the input shaft and output shaft.
  • The mode fork and synchronizer sleeve engage the output shaft and drive gear.

• (4H) is displayed in the message center.