Serviceable components of the PTU are limited to the output shaft seal and flange, intermediate shaft seal and
deflector, and the PTU-transaxle compression seal. No internal components are serviced. There should be no
need to remove the PTU cover. If any of the internal geared components, bearings, case cover or shafts are worn
or damaged, a new PTU must be installed.
FOUR WHEEL DRIVE (4WD) SYSTEMS - ALL WHEEL DRIVE (AWD)
Principles of Operation
The vehicle is equipped with a four wheel drive (4WD) system, also referred to as active torque control
coupling (ATCC) or intelligent torque control coupling (ITCC) , that is always active and requires no driver
input. The system has no mode select switch. The system combines transparent all-surface operation with all
wheel drive (AWD), and is capable of handling all road conditions, including street and highway driving as well
as off-road and winter driving.
The system continuously monitors vehicle conditions and automatically adjusts the torque distribution between
the front and rear wheels. During normal operation, most of the torque is sent to the front wheels. If wheel slip
between the front and rear wheels is detected, or if the vehicle is under heavy acceleration (high-throttle
osition), the AWD system increases torque to the rear wheels to prevent or control wheel slip.
Illustration Tool Name Tool Number
73III Automotive Meter 105-R0057 or equivalent
Flex Probe Kit 105-R025C
Vehicle Communication Module
(VCM) and Integrated Diagnostic
software with appropriate
hardware, or equivalent scan tool
2008 Ford Edge SE
2008 TRANSMISSIONS Four Wheel Drive (4WD) Systems - Edge & MKX
Friday, September 25, 2009 10:52:32 AM Page 2 © 2005 Mitchell Repair Information Company, LLC.