Four-Wheel Drive Systems: Notes
For transfer case repair procedures, refer to TRANSFER CASE - AUTOMATIC SHIFT .
The electronic shift on the fly system is an electronically-shifted four wheel drive system that allows the operator to choose between three different modes. The operator can switch between 2WD and 4WD HIGH modes at any speed. To engage or disengage 4WD LOW range, the vehicle speed must be less than 5 km/h (3 mph), the brake pressed, the automatic transmission must be in NEUTRAL, or the clutch must be pressed for manual transmission.
The shift motor sense plate, an integral part of the electric shift motor, informs the four-wheel drive (4WD) control module to the position of the transfer case.
The digital TR sensor is located on the LH side of the automatic transmission; this sensor informs the 4WD control module when the automatic transmission is in the NEUTRAL position.
The electric shift motor is mounted externally at the rear of the transfer case. It drives a rotary cam which moves the mode fork and range fork within the transfer case between the 4WD HIGH, 4WD LOW and 2WD positions.
The 4WD shift motor is controlled by the 4WD control module to shift the transfer case between 4WD HIGH, 4WD LOW and 2WD modes.