Four-Wheel Drive Systems: Overview Ford Escape I

Principles of Operation-Electric Shift

The front-wheel drive transaxle utilizes a transfer case unit to transfer power through a driveshaft and universal joints to the rotary blade coupling (RBC) mounted to the rear differential.

The mode select switch (MSS) has two positions: AUTO and 4X4 ON. In the AUTO position, the system is in two-wheel drive until the front wheels begin to slip. The spinning of the front wheels causes a relative speed difference between the front and rear axles and turns a rotary blade mounted in silicone fluid. The turning rotary blades builds pressure in the silicone fluid, which pushes a piston, compressing the clutch plates of the RBC and transferring torque to the rear wheels. The torque applied to the rear axle is a function of the difference in wheel speed between the front and rear wheels. When slip is no longer present at the front wheels, the system reverts to front-wheel drive.

The 4X4 ON mode energizes the four-wheel drive relay, which supplies power to the integral electrical clutch to lock the RBC and transfer power from the rotating driveshaft to the rear wheels. In the 4X4 ON mode all wheels are driven full-time until the switch is turned to another position.

Scheme 2

1. Visually inspect for obvious signs of mechanical and electrical damage.
2. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
3. If the concern is not visually evident, verify the symptom and refer to the «Symptom Chart»(ref-194830-S18724434422005092900000) .

Scheme 3

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Scheme 11

1. Remove the mode select switch (MSS) knob.
2. Remove the instrument panel center finish panel.
3. Remove the MSS. Remove the screws. Remove the MSS.
4. To install, reverse the removal procedure.