Peterbilt 325 2017, Operator'S Manual

Page: 174 / 392

OPERATING THE BRAKE SYSTEM
•
Improves vehicle control and
helps reduce stopping distances
in off-road conditions or on poor
traction surfaces such as loose
gravel, sand and dirt.
•
Allows retarders to function
independently of the ABS function.
•
If your vehicle does not have an
engine retarder, the Off-Road ABS
switch will function the same.
CAUTION
Never drive your vehicle on im-
proved roads/highways with the
Off-Road ABS function turned on.
When you drive your vehicle onto an
improved road surface or highway,
immediately turn off the Off-Road
ABS switch.
Failure to do so will
cause the ABS system to not func-
tion properly in an ABS event under
25 mph and could result in an acci-
dent or personal injury.
WARNING!
While the off-road mode can im-
prove vehicle control and shorten
stopping distances, some steering
ability may be reduced on certain
surfaces resulting from the momen-
tarily sliding tires.
Always oper-
ate your vehicle at safe operating
speeds. Failure to do so may cause
you to lose control of the vehicle
and could result in an accident or
personal injury.
How The Off-Road ABS Function
Works
•
The ABS lamp flashes slowly
during off-road mode engagement.
This is done to alert you of a
modification to the ABS control
software.
•
At speeds above 25 mph, the ABS
controller operates in the normal
on-highway mode.
•
At speeds between 10 and 25
mph, the ABS control software is
modified to allow short periods
(0.25 seconds) of locked-wheel
cycles.
•
At speeds below 10 mph, the ABS
control software is turned off to
allow locked wheels.
•
When the Off-Road ABS function
is enabled, the Retarder Disable
output is turned off. That is,
the engine retarders are left to
function without ABS intervention.
For additional information, see the
Off-Road ABS pamphlet in your
vehicle’s glove box.
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Y53-6060-1C1 (03/17)
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