operators_manual

WARNING!
Do not rely on an anti-lock brake system
that is functioning improperly. You could lose
control of the vehicle resulting in a severe
accident, causing death or personal injury. If
your ABS lamp goes on while you are driv-
ing or stays on after the self-check, your an-
ti-lock system might not be working. The
ABS may not function in an emergency. You
will still have conventional brakes, but not
anti-lock brakes. If the lamp indicates a
problem, have the ABS checked.
Vehicles without anti-lock brake systems
(ABS) are typically equipped with a bobtail
brake proportioning system. When a trailer
is not connected, the drive axle brake
application pressure will automatically be
limited by the proportioning system. When
driven in a bobtail mode, these tractors will
require greater brake pedal application to
provide the equivalent braking to a bobtail
tractor not equipped with a proportioning
system.
Trailer ABS Pwer Line
Communication (PLC)
North American on-highway vehicles are
equipped with a separate electrical circuit
to power the anti-lock brake system (ABS)
on towed vehicle(s). In most cases, the
ABS power will be supplied through the
Auxiliary circuit on the primary 7-way trailer
light line connector. If the vehicle was
manufactured with a switchable Auxiliary
circuit for trailer accessories, an additional
7-way connector would have been
provided for trailer ABS power. In either
case, the ABS power line on the vehicle
will be PLC equipped.
CAUTION
Do not splice into the non-switchable Auxili-
ary circuit on the primary 7-way trailer light
line. Doing so may cause the trailer ABS to
malfunction. This circuit is dedicated for
trailer ABS power. To add a switchable aux-
iliary circuit, contact a dealership.
NOTE
Tractors/Trucks and trailers built after
03/01/2001 must be able to turn on an In-
Cab Trailer ABS Warning Lamp (per U.S.
FMVSS121). The industry chose Power
Line Communication (PLC) as the standard
method to turn it on. On trailers built prior to
03/01/2001 verify trailer ABS system status
via the required external warning lamp
mounted on the trailer. The indicator lamp
on the trailer should be yellow and identified
with the letters ABS.
For doubles or triples, the lamp does not
distinguish between trailers. An ABS
problem in any of the trailers will activate
the Trailer ABS Warning Lamp.
If you change the intended service in any
way (e.g., number of axles, multiple
trailers, add switchable trailer accessories,
etc.) from the date the vehicle was
manufactured, you should contact your
trailer manufacturer and/or trailer anti-lock
brake manufacturer to determine if the
power available at the 7-way trailer light
line is adequate. Failure to do so might
result in insufficient power to the trailer
ABS system, which may affect its
operation.
CAUTION
The center pin of the 7-way trailer light line
may be constantly powered for ABS. Make
sure it will not accidently turn on trailer
equipment.
DRIVING - Brakes
108 Y53-6096-1A1 (01/17)
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