Polaris 2012 Sportsman Forest 500 International, Service Manual

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7.19
FINAL DRIVE
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9923412 - 2012 Sportsman 400/500 and EFI Tractor Service Manual
© Copyright 2011 Polaris Sales Inc.
ADC Operation
Engaging Front Gearcase: Active Descent Control
(ADC) is controlled by the ECU and will not enable until the
following conditions are met:
• Vehicle speed is below 15 Mph (24Kph)
• Throttle Position Sensor (TPS) is at idle position
• The AWD switch is switched to ‘AWD/ADC’
Once the conditions are met for engagement, ADC
remains engaged as long as the conditions are met. With
the AWD switch set to ‘2x4’, the vehicle drives only the rear
wheels (2 wheel drive). When the AWD switch is set to
‘4x4’ the magnetic coils are active, the AWD coil indexes
the clutch mechanism so that both front axles will engage
when there is a loss of rear wheel traction. In addition to
the rear wheel engine braking, the ADC coil provides front
wheel engine braking at speeds less than 15 Mph (24Kph)
with the TPS at idle position.
ADC Engagement: When the AWD switch is set to ‘4x4/
ADC’, a 12 Vdc current is present at the input shaft coil (1) .
Operation is controlled by the ECU grounding and
ungrounding the coil. The coil’s magnetic field attracts a
splined armature plate
(2) on the pinion (input) shaft (4) .
The energized splined armature plate attracts the
unsplined eccentric cam
(3) , which begins to turn with the
input shaft. The eccentric cam pushes on the hydraulic
piston/pump assembly
(5) . The pressure created by the
pump assembly forces hydraulic fluid through passages to
the piston assemblies
(6) located in each case half.
Hydraulic pressure forces the piston assemblies inward to
compress the splined clutch packs
(7) forming a dynamic
coupling to each front drive axle, resulting in true all-wheel
EBS operation upon deceleration.
Disengagement: Current to the ADC coil is turned off by
the ECU anytime the following conditions are met:
• Throttle Position Sensor (TPS) moves off idle
position
• The AWD switch is switched to ‘4x4’ or ‘2x4’
• Vehicle speed is above 15 Mph (24Kph)
Hydraulic pressure stops and the pistons release,
disengaging the ADC function. The vehicle returns to rear
wheel drive until the next deceleration.
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