Lesson 3: powertrain – FORD FCSD TECHNICAL TRAINING FCS-14000-DL User Manual

Page 82

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LESSON 3: POWERTRAIN

Shift Patterns

Under certain conditions the transmission automatically downshifts to a lower gear range (without moving the

range selector lever). There are three categories of automatic downshifts:

– coastdown

– torque demand

– forced or kickdown shifts

Coastdown

The coastdown downshift occurs when the vehicle is coasting to a stop.

Torque Demand

The torque demand downshift occurs (automatically) during part throttle acceleration when the demand for torque

is greater than the engine can provide at that gear ratio. If applied, the transmission will disengage the Torque

Converter Clutch (TCC) to provide added acceleration.

Kickdown

For maximum acceleration, the driver can force a downshift by pressing the accelerator pedal to the floor. A

forced downshift into a lower gear is possible below calibrated speeds. Specifications for downshift speeds are

subject to variations due to tire size, engine and transmission calibration requirements.

2005 Expedition/Navigator New Model Technician Training

02-SEP-04

3-46

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