3
This will be the case when an MC-30
™
controller is installed
on a powered vehicle auxiliary axle.
Identifying / Measuring the PLC Signal
An MC-30
™
controller with PLC will continuously broadcast
PLC messages that indicate trailer ABS status. At power-
up or during a trailer ABS fault condition, the MC-30
™
controller will signal the tractor ABS unit to illuminate the
dash mounted trailer ABS indicator lamp.
Diagnostic tools are available that detect the presence
of a PLC signal and perform further system diagnostics
directly on the power line. For more information on these
diagnostic tools, contact Bendix or refer to your local
authorized Bendix dealer.
An oscilloscope can also be used to verify the presence
and strength of a PLC signal on the power line. The PLC
signal is an amplitude and frequency modulated signal.
Depending on the load on the power line, the amplitude of
the PLC signal can range from 5.0 mV p-p to 7.0 V p-p.
Suggested oscilloscope settings are (AC coupling, 1 volt/
div, 100
µ
sec/div). The signal should be measured on
pin 7 of the J560 connector at the nose of the trailer. See
Figure 3 and Figure 4 for examples of PLC measurements
using an oscilloscope.
All connector leads of the MC-30
™
controller pigtail harness
are weather sealed at the connector interface and are
clearly labeled for proper installation.
Non over-molded versions of the MC-30
™
controller pigtail,
shown in Figure 5, are repairable. If repairs are needed,
see chart 12 for connector and tool information.
Over-molded versions of the wiring harness must be
replaced if corrosion or damage occurs.
ECU Connector
The 30-pin ECU connector of the pigtail is fastened to the
EC-30T
™
controller with a jackscrew tightened to 15-20
in. lbs. Improper tightening of the connector jackscrew
can cause environmental contamination or damage to the
EC-30T
™
controller. The use of a inch-pound torque wrench
is recommended.
Power / ABS Indicator Lamp Connector
The MC-30
™
controller pigtail utilizes the TTMA RP 97-99
5-pin Packard Weather Pack connector for brake light
power, constant power, ground and the trailer mounted ABS
indicator lamp. The Power/ABS Indicator Lamp lead of
the pigtail harness is available in various lengths to satisfy
installation requirements such as slider axles.
Wheel Speed Sensor Connectors
Two or four wheel speed sensor connectors are provided.
These 2-pin connectors are labeled Right Front (RHT FRT),
Left Front (LFT FRT), Right Rear (RHT RER) and Left Rear
(LFT RER). Right Front and Left Front wheel speed sensor
inputs must be used for two sensor installations, even if
the wheel speed sensors are not physically located on the
forward axle. Extension cables are available from Bendix
that will provide longer wheel speed sensor lengths when
required by the installation.
ABS Modulator Connectors
One or two modulator connectors are provided. These 3-pin
connectors are labeled MOD 1 and MOD 2. Modulator 1
is always used for single modulator installations. For two
modulator confi gurations, Modulator 1 is installed at the
right or front position. Modulator 2 is installed at the left
or rear position. An extension cable must be used for
Modulator 2. The remote modulator harness is available
in various lengths to satisfy any installation requirement.
See Figure 6.
Diagnostic Connector
An optional 4-pin diagnostic connector provides a port
for connecting a diagnostic tool. The connector provides
ignition power, ground and data lines. Remote diagnostic
cables are available from Bendix that will provide a
standard J1708/J1587 diagnostic port at the side of the
trailer. See Figure 7.
FIGURE 3 - POWER LINE WITHOUT PLC SIGNAL
FIGURE 4 - POWER LINE WITH PLC SIGNAL
MC-30
™
CONTROLLER WIRING HARNESS
(PIGTAIL)
The EC-30T
™
controller utilizes a pigtail wire harness to
interface with ABS and other trailer system components.
Various pigtail harness part numbers are available from
Bendix. The following connectors are optional and may not
be present on all pigtail harnesses: Modulator 2, auxiliary,
diagnostic, and rear axle wheel speed sensors.
