Electronic Shift Transfer Case

WARNING: This page is about a different car, the 2009 Ford Pickup, 2009 Ford F550 Super Duty, 2009 Ford F450 Super Duty, and 2009 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.

The New Venture Gear NV 273 electronic shift transfer case is a 3-piece aluminum design. The unit transfers engine power from the transmission to the front and rear axles. Under normal driving conditions the unit is in 2WD, but when desired, the operator may shift into 4X4 High or 4X4 Low. The transfer case is shifted electronically. The unit is lubricated by a positive displacement fluid pump that channels fluid flow through holes in the mainshaft.

The encoder assembly used for mode indication is of a Hall effect type. The system uses a total of 4 independent transistors for mode recognition. Each transistor is associated with a specific range of motor movement. When the circuit to each transistor is closed, a ground path to any of the -A-, B-, C- or D- encoder pins is accomplished. When the circuit to each transistor is open, the connection to any of the -A-, B-, C- or D- encoder pins is pulled to voltage. Mode indication is "decoded" by the 4X4 control module based on the varying combinations of signals coming from the transistors.