Using the Brake System Operating Instructions
– 82 – Y53-6008
Medium Duty (R10/06)
Trailer ABS Warning Lamp
Trucks, tractors, and trailers built on and after March 1, 2001
are equipped with power line communication (PLC) per U.S.
FMVSS 121, including a trailer ABS warning lamp in the cab.
CAUTION: If the trailer ABS warning lamp does
not illuminate when the ignition is first turned
on, there is a problem with the bulb or wiring.
The driver should have this checked as soon as
possible.
NOTE: A successsful warning lamp illumination and
bulb check at ignition on does not
indicate that the
trailer you may be connected to has trailer ABS. You
should personally inspect every trailer to determine
its braking system.
A trailer ABS warning lamp will illuminate for a bulb check
when the ignition switch is first turned on - whether or not a
trailer is connected to the vehicle. If the bulb check is satis-
factory, the lamp will next do either of the following:
1. If no trailer is connected, or if a non-ABS-equipped trailer
is connected, the trailer ABS lamp will go off after a few
seconds.
NOTE: A “properly connected” ABS-equipped trailer
is
• a trailer with PLC hooked up to the J560 con-
nector.
• a trailer without PLC that is hooked up to an
optional ISO 3731 connector.
NOTE: For doubles or triples: PLC does not dis-
tinguish between trailers. An ABS problem in any
trailer will activate the trailer ABS warning lamp.
2. If an ABS-equipped trailer is properly connected, the
trailer ABS warning lamp will remain illuminated for a few
more seconds while the trailer ABS is tested.
• If no trailer ABS problems are detected, the
lamp will go off.
ABS
