BENDIX MC-30 TRAILER ABS CONTROLLER User manual

1
SD-13-4834
MC-30™CONTROLLER INTRODUCTION
TheMC-30™controlleristheBendixantilockbrakingsystem
(ABS) controller assembly intended for application on air
braked heavy duty trailers, semi-trailers and dollies.
The Bendix®MC-30™controller features an integral LED
diagnosticdisplay withmagnetic resetfor easydiagnostics
andfaultcode clearing.Blinkcode diagnosticsarestandard
and advanced diagnostic tool support is also available.
The MC-30™controller supports PLC communication
for indicator lamp, full diagnostics capability and other
customized features.
The ABS function of the MC-30™controller is designed to
providea towed vehiclewith improvedstability and control
during braking while providing the maximum available
braking force.
Bendix®MC-30™Trailer ABS Controller Assembly
FIGURE 1 - MC-30™CONTROLLER TANK (NIPPLE)
MOUNT ASSEMBLY
Supply Port
1/2" NPT
ABS Modulator
Connector
(MOD1)
Delivery Ports
3/8" NPT (x4)
LED Diagnostic
Display 30-Pin
Connector
Control
Port
1/4" NPT
For updates to this Service Data Sheet, please visit www.bendix.com.
TABLE OF CONTENTS PAGE
Components . . . . . . . . . . . . . . . . . . . . . . .2
MC-30™Controller Comparison to MC-12™Modulator. .2
MC-30™Controller Assemblies. . . . . . . . . . . . . .2
MC-30™Controller with PLC . . . . . . . . . . . . . . .2
Wiring Harness (Pigtail) . . . . . . . . . . . . . . . . .3
Power and Ground. . . . . . . . . . . . . . . . . . . .5
ABS Indicator Lamp . . . . . . . . . . . . . . . . . . .5
Wheel Speed Sensors . . . . . . . . . . . . . . . . . .5
M-30T™ABS Modulator-Valves . . . . . . . . . . . . .6
J1708/J1587 Diagnostic Link . . . . . . . . . . . . . .6
Auxiliary I/O . . . . . . . . . . . . . . . . . . . . . . .6
MC-30™Controller Power-up Sequence . . . . . . . . .7
ABS Operation . . . . . . . . . . . . . . . . . . . . . .7
Self-Configuration/Control Toggle . . . . . . . . . . . .8
Other Configurable Parameters . . . . . . . . . . . . 11
Odometer Function. . . . . . . . . . . . . . . . . . . 11
Fault Detection. . . . . . . . . . . . . . . . . . . . . 11
MC-30™Controller Diagnostic Display . . . . . . . . . 12
Blink Code Diagnostics . . . . . . . . . . . . . . . . 13
Bendix ABS Diagnostic Tools . . . . . . . . . . . . . 16
Contacting Bendix . . . . . . . . . . . . . . . . . . . 16
Correct Maintenance Practices . . . . . . . . . . . . 16
Servicing the MC-30™Controller. . . . . . . . . . . . 17
Replacing the EC-30T™Controller . . . . . . . . . . . 17
Overhaul of the Relay Valve . . . . . . . . . . . . . . 17
MC-12™Modulator / MCE-12 Service-Replacement. . 17
Reinstallation of the MC-30™Controller or
M-30T™Modulator-Valve. . . . . . . . . . . . . . . . 18
Leakage and Operational Tests . . . . . . . . . . . . 18
ABS Wiring. . . . . . . . . . . . . . . . . . . . . . . 18
Troubleshooting Flowcharts . . . . . . . . . . . . . . 24
Product Revision / Feature Introduction . . . . . . . . 32

2
MC-30™CONTROLLER COMPONENTS
The MC-30™controller ABS installation consists of the
following components:
- EC-30T™ABS Electronic Control Unit (ECU) (1)
- M-30T™ABS modulator-valve with relay function (1 or 2)
- WS-20™wheel speed sensors (2 or 4)
- Sensors spring clips (2 or 4)
- Trailer mounted ABS indicator lamp
- Pigtail wiring harness
- PLC signal for dash mounted trailer ABS indicator lamp
(Towed vehicles manufactured after March 1, 2001)
MC-30™CONTROLLER COMPARISON TO
MC-12™MODULATOR
The MC-30™controller has been designed to replace the
MC-12™modulator as the standard Bendix trailer ABS
controllerassembly forOEM and aftermarketinstallations.
The EC-30T™controller has a black plastic enclosure
similar to the Bendix®EC-30™tractor ABS controller, and
is mounted to the modulator-valve with a bracket. The
MC-12™modulator utilized a metal ECU enclosure and
was directly bolted to the modulator body. The MC-30™
controllerhasa 30-pinelectrical connectorandthe MC-12™
modulator has a 14-pin connector.
The M-30T™ABS modulator-valve utilizes a 3-pin external
electrical connector, where the MC-12™modulator used a
4-pin internal connector.
MC-30™CONTROLLER ASSEMBLIES
Tank (Nipple) Mounted
TheMC-30™controllertank-mount assemblyis mountedby
usinga schedule80(heavy gaugesteel)1/2" nippledirectly
between the trailer supply tank and the MC-30™modulator-
valvesupplyport. Atankwitha reinforcedportmustbeused.
See Figure 1 for tank-mount MC-30™modulator-valve.
CAUTION: The tank-mounted MC-30™modulator-valve
cannot be mounted on a frame or crossmember using the
ECU bracket holes.
Bracket (Chassis) Mounted
TheMC-30™controllerbracket mountassembly ismounted
directlyto thetrailer framerailor crossmember. See Figure
2 for bracket mount MC-30™controller. The bracket studs
are secured using three 5/16-18 nuts and lock washers
torqued to 180-220 in-lbs.
MC-30™CONTROLLER WITH PLC
Effective March 1, 2001 all towed vehicles must transmit a
signaltocontrolanin-cabtrailerABSindicatorlamp. Trailers
builtafterthisdatewilltransmitthestatusofthetrailerABSunit
overtheignitionpowerwire(blue wireoftheJ560connector)
using Power Line Carrier (PLC) communications.
ThePLCsignal isusuallybroadcast bythetrailerABSECU.
The application of PLC technology for the heavy vehicle
industry is known as PLC4Trucks. MC-30™controller
modelswithPLC willsupportcommunication inaccordance
with SAE J2497.
Identifying MC-30™Controller units with PLC
Most MC-30™controller units will contain PLC capability.
However, some MC-30™controller units installed prior to
March 1, 2001 may not. An MC-30™controller with PLC
canbe identifiedbythe individualpart numberlabeland pin
stamp on the EC-30T™controller housing. On PLC units,
the PLC function can be disabled with a diagnostic tool.
FIGURE 2 - MC-30™CONTROLLER BRACKET (FRAME)
MOUNT ASSEMBLY
Physical MC-30™MC-12™
Feature Controller Modulator
ECU Enclosure Plastic ECU Metal ECU
ECU Mounting Bracket Mounted to Directly Mounted to ABS
ABS Modulator Valve Modulator Valve Body
ECU Electrical 30-pin 14-pin
Connector
ABS Modulator 3-pin External 4-pin Internal
Connector Connector Connector
CHART 1 - MC-30™CONTROLLER AND MC-12™
MODULATOR DIFFERENCES
EC-30T™TRAILER ABS ECU
The EC-30T™is a plastic electronic controller with a
single 30-pin electrical connector. The EC-30T™controller
enclosure is filled with a hard epoxy-based potting that
seals all internal components from the environment. A
patented LED (light emitting diode) diagnostic display
and magnetic reset switch are incorporated in the housing
for simple, self-contained diagnostics. The design of the
EC-30T™controller’s electronics is robust against radio,
electromagnetic and environmental interference.
The EC-30T™controller is typically mounted to the
M-30T™modulator-valve using four bolts and a bracket.
This assembly forms an MC-30™ABS controller.
The EC-30T™controller can also be frame rail mounted,
independent of the M-30T™modulator-valve.

3
Thiswill bethecase whenan MC-30™controlleris installed
on a powered vehicle auxiliary axle.
Identifying / Measuring the PLC Signal
AnMC-30™controller withPLC willcontinuously broadcast
PLC messages that indicate trailerABS 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 µsec/div). The signal should be measured on
pin 7 of the J560 connector at the nose of the trailer. See
Figure3 and Figure4 forexamples of PLCmeasurements
using an oscilloscope.
Allconnector leadsofthe MC-30™controllerpigtail harness
are weather sealed at the connector interface and are
clearly labeled for proper installation.
Nonover-molded versionsof theMC-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 useofainch-pound torquewrench
is recommended.
Power / ABS Indicator Lamp Connector
The MC-30™controller pigtail utilizes the TTMARP 97-99
5-pin Packard Weather Pack connector for brake light
power, constantpower,groundand thetrailermountedABS
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.
These2-pinconnectors arelabeledRight Front(RHTFRT),
LeftFront (LFTFRT),RightRear(RHTRER) andLeft Rear
(LFTRER). RightFront andLeftFront wheelspeed 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
Oneortwomodulatorconnectorsareprovided. These3-pin
connectors are labeled MOD 1 and MOD 2. Modulator 1
is always used for single modulator installations. For two
modulator configurations, 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.Thefollowing connectorsare optionaland maynot
be present on all pigtail harnesses: Modulator 2, auxiliary,
diagnostic, and rear axle wheel speed sensors.

4
Auxiliary I/O Connector
An optional auxiliary connector provides a connection to
the MC-30™controller auxiliary feature I/O pins. The five
auxiliaryground-switchinputs andtwoauxiliary outputscan
be activated and configured with a diagnostic tool.
FIGURE 5 - MC-30™CONTROLLER PIGTAIL HARNESS (4S/2M WITH DIAGNOSTIC AND AUXILIARY CONNECTORS
SHOWN)
30-Pin ECU
Connector
8-Pin Auxiliary
(AUX)
3-Pin Modulator 2
(MOD2)
3-Pin Modulator 1
(MOD 1)
4-Pin Diagnostic
(DIAG)
5-Pin Power and
Indicator Lamp
(PWR/WL) 2-Pin Wheel
Speed Sensors
ECU Connector Jackscrew
(Tighten to 15-20 in. lbs.)
Left Rear
(LFT RER)
Right Rear
(RHT RER)
Left Front
(LFT FRT)
Right Front
(RHT FRT)
FIGURE 6 - REMOTE MODULATOR HARNESS (MOD2)
Modulator 2
(MOD2)
To
Pigtail
FIGURE 7 - REMOTE DIAGNOSTIC HARNESS
To
Pigtail To Diagnostic Tool
POWER AND GROUND
Trailer electricalpower issupplied totheMC-30™controller
fromthe ignitionand brakelight circuits.Note:The MC-30™
controller may not function properly when powered with a
battery charger. See Chart 2.

5
ABS INDICATOR LAMP
Trailer Mounted Lamp
The MC-30™controller controls an ABS indicator lamp
to indicate the trailer ABS status. The MC-30™controller
directly controls the ABS indicator lamp by providing a
12.0 VDC signal to turn it on. The other side of the lamp
is grounded. The MC-30™controller must be powered in
order to operate the trailer indicator lamp. Pin D3 of the
30-pin connector is the ABS indicator lamp output.
Dash Mounted Lamp (PLC Controlled)
MC-30™controllermodels withPLC willtransmit asignal to
control a trailer ABS indicator lamp mounted on the dash
of the tractor. MC-30™controller will transmit the status of
the trailer ABS unit over the ignition power pin E1 of the
30-pinconnector. The ignition powerwire (blue wireof the
J560 connector) will carry this signal to the towing vehicle.
MC-30™controllermodelswithPLC supportcommunication
in accordance with SAE J2497.
WHEEL SPEED SENSORS
Wheel speed data is provided to the MC-30™controller
from the Bendix wheel speed sensors. See Figure 8 for
examples. Working with a tone (exciter) ring, the wheel
speed sensors provide the MC-30™controller with an AC
signal, which varies in voltage and frequency in relation
to the speed of the wheel. The MC-30™controller is
configured to receive wheel speed information from 100
tooth tone rings by default. Vehicle axle and ABS control
configurationsdetermineiftwo orfourwheel speedsensors
must be used. See the MC-30™controller’s electrical
system schematic for wheel speed sensor connector pin
locations, Figure 16.
Circuit 7-Pin Trailer 5-Pin ABS 30-Pin ECU
Electrical Power Connector
Connector Connector
Ignition Power (PLC) Pin 7 B Pin E1
(Blue Wire)
Brake Light Power Pin 4 A Pin E3
(Red Wire)
Ground Pin 1 E Pin D2
(White Wire)
Indicator Lamp N/A D Pin D3
(White/Green Wire)
Function Mode Value
Operating Range 8.0 to 16.0 VDC
ECU Active 383 mA
ABS Active 2.4 A @ 12 VDC
(1 modulator)
ABS Active 4.5 A @ 12 VDC
(2 modulators)
CHART 2 - POWER AND GROUND
FIGURE 8 - BENDIX WHEEL SPEED SENSORS
CLIP AND SENSOR INSERTION
90° Speed
Sensors
Straight Speed
Sensors
PREVIOUS AND NEW CLAMPING SLEEVES
WS-24
sensors use
clamping
sleeves with
“BX” in a
swoosh
symbol
Previous
clamping
sleeves have
“BW” in a
diamond
Previous Bendix Wheel Speed Sensors
Previous sensors are all replaced by the
Bendix WS-24™wheel speed sensor shown below.
FIGURE 9
FIGURE 10
Wheel Speed Sensor Clips
The sensor spring clip is designed to firmly hold the wheel
speed sensor in place while also allowing the sensor to
adjust in position as the wheel and hub rotate. Wheel
bearing play and heavily loaded axles will cause sensors
to self-adjust. Proper sensor installation begins by fully
inserting the spring clip into the block, with the retaining
tabs toward the inside of the vehicle. See Figure 9.

6
Wheel Speed Sensor Adjustment
Speed sensors are properly adjusted by gently pushing
(not striking) the sensor into the clip until it makes contact
with the face of the tone ring. The wheel speed sensor
will automatically adjust as the wheel rotates. If rotating
the wheel causes a gap of 0.020 in. or greater, check for
excessive wheel bearing play or tone ring runout. Proper
wheel speed sensor installation is critical to proper ABS
operation. See Figure 10.
M-30T™ABS MODULATOR-VALVES
The M-30T™Bendix®trailer ABS modulator-valve is
controlledbytheEC-30T™controllertomodifydriver applied
airpressuretotheservicebrakesduringABSactivation. The
ABSmodulator-valve isan electro-pneumaticcontrol valve
and is the last valve that air passes through on the way to
thebrakechambers. The holdandexhaust solenoidsofthe
M-30T™modulator-valve are activated to precisely modify
thebrakepressureoncommand. The EC-30T™controlleris
designedtocontrol oneortwo modulator-valveassemblies.
See the MC-30™controller’s electrical system schematic
for ABS modulator connector pin locations, Figure 16.
The M-30T™modulator-valve is available in two mounting
configurations.
FIGURE 11 - M-30T™TANK (NIPPLE) MOUNT
MODULATOR-VALVE
FIGURE 12 - M-30T™BRACKET (FRAME) MOUNT
MODULATOR-VALVE
Tank (Nipple) Mounted
The M-30T™modulator-valve tank-mount assembly is
mounted by using a schedule 80 (heavy gauge steel) 1/2"
nipple directly between the trailer supply tank and the
M-30T™modulator-valve supply port. A tank with a
reinforced port must be used. See Figure 11.
Bracket (Chassis) Mounted
The M-30T™modulator-valve bracket mount assembly is
mounted directly to the trailer frame rail or crossmember.
See Figure 12. The bracket studs are secured using
three 5/16-18 nuts and lock washers torqued to 180-220
in-lbs.
J1708/J1587 DIAGNOSTIC LINK
TheMC-30™controller provides aJ1708/J1587 diagnostic
link with data and power to communicate with the vehicle
and various diagnostic tools. Diagnostics, testing,
configuration, data transfer and other functions can be
performed using this link. The MC-30™controller is
supported by diagnostic tools such as the MPSI Pro-Link®
andBendix®ABSDiagnostic Software. Ignitionpowermust
beprovided tothe MC-30™controller forthe diagnosticlink
to be active. See the MC-30™controller electrical system
schematic for J1708/J1587 diagnostic link pin locations,
Figure 16.
AUXILIARY I/O
Auxiliary Function Inputs
The MC-30™controller offers five auxiliary ground switch
inputs. These inputs can be configured for various
custom functions using a diagnostic tool. See the
MC-30™controller’ssystemelectricalschematic forauxiliary
function input connector pin locations, Figure 16.
Auxiliary Function Outputs
The MC-30™controller offers two auxiliary output drivers.
These outputs can be configured for various custom
functions. Pin F1 of the 30-pin connector is the auxiliary
low side output. Pin K2 of the 30-pin connector is the
auxiliary high side output.
MC-30™CONTROLLER POWER-UP
SEQUENCE
At power-up, the MC-30™controller performs a series of
self-checks that can assist a technician in determining the
status and configuration of the system.
Trailer ABS Indicator lamp
At power-up without detected faults, the trailer ABS
indicator lamp will illuminate for 2.5 seconds as a bulb
check and then turn off.

7
ABS OPERATION
The MC-30™controller uses wheel speed sensors, ABS
modulator-valves and an ECU to control trailer wheels by
axle or by side. By detecting excessive wheel slip during
brakingand adjustingthe pressureto eachbrakechamber,
the MC-30™controller is able to optimize slip between the
tireand the roadsurface. The EC-30T™controllercontrols
theABS modulator-valves, similar to a driver pumping the
brakes. However, theMC-30™controllerisable topumpthe
brakes on the vehicle with greater speed and accuracy.
Axle Control
MC-30™controller axle control will utilize a single ABS
modulator-valve to control wheels from both sides of a
given axle or axles. In the case of an unbalanced braking
surface, axle control will control the high coefficient wheel
just under the lock limit. Temporary periods of wheel lock
are permitted on the low coefficient wheel. Axle control
shouldnot be usedon 5thwheel dolliesor steerable axles.
When braking on even surfaces, an axle-control system
willperform similarto aside control,twomodulator system.
Axle control is available in 2S/1M, 2S/2M and 4S/2M
installations.
Dolly-Axle Control (Select Low)
MC-30™controller dolly-axle control will utilize a single
ABS modulator-valve to control wheels from both sides of
agiven axleor axles. Inthe caseof anunbalancedbraking
surface, dolly-axle control will control the low coefficient
wheel just under the lock limit. Optimal vehicle stability
is achieved by not allowing the high coefficient wheel to
sustainwheellock. When brakingoneven surfaces,a dolly
axle control system will perform similar to side control or
axle control system. Dolly axle control is only available in
2S/1M installations.
Steer Axle Option (MOD2 Select Low)
This option causes MOD2 to be Dolly-Axle controlled and
isonly active whileconfigured for4S/2MAxle control. This
configurationoption should be setwhen MOD2 isinstalled
on a forward or steer axle of a full trailer. SteerAxle option
can be set using a diagnostic tool or by purchasing an
MC-30™controller unit with this option pre-set.
Side Control
The MC-30™controller will utilize a singleABS modulator-
valveto controloneor morewheelson agiven vehicleside.
In the case of an unbalanced braking surface, MC-30™
controllerside controlwill individuallycontrol eachside just
under the lock limit. Side control is available in 2S/2M and
4S/2M installations.
Normal Braking
During normal braking, the MC-30™controller functions as
a standard relay valve. As brakes are applied or released
by the driver, the control signal from the tractor foot valve
causes the M-30T™modulator-valve to apply proportional
pressure to the trailer brake chambers.
If a PLC tractor and PLC trailer are powered at the same
time, the MC-30™controller will also trigger a bulb check
on the tractor dash using PLC.
Diagnostic LED Display of Configuration
Atpower-up,the diagnosticLEDsallilluminate, thendisplay
thecurrent configuration forsensors, modulators andABS
control. See chart 3. After displaying the configuration,
only the green VLT LED will stay on. However, if a fault is
detected, the faulted component will be displayed by the
red diagnostic LEDs.
CHART 4 - MC-30™CONTROLLER ABS CONFIGURATIONS
System Sensors Modulators Available
Configuration 2 4 1 2 ABS Control Settings
2S/1M X X Axle or Dolly-Axle
2S/2M X X Axle or Side
4S/2M X X Axle or Side
CHART 3 - LED POWER-UP SEQUENCE
MC-30™Controller – LED Power-Up Sequence
At power-up All LEDs
1st blink displays number of wheel speed sensors
2 Sensors SEN-FRT
4 Sensors SEN-RER-FRT
2nd blink displays modulator configuration
1 Modulator (Dolly-Axle control) MOD
1 Modulator (Axle control) MOD-FRT
2 Modulators (Axle control) MOD-RER-FRT
2 Modulators (Side control) MOD-LFT-RHT
Normal Operation
No Faults VLT (green) LED illuminated only
Modulator Chuff Test at Power-Up
At power-up, the MC-30™controller activates a modulator
chuff test. This electrical and pneumatic ABS modulator
testcan assistthe technicianin verifyingthatthe modulator
wiring and installation are correct. With brake pressure
applied, a properly installed modulator will cause five
rapid audible chuffs of air pressure. If two modulators
are installed, the MC-30™controller activates 5 chuffs at
Modulator1 (MOD 1)then Modulator2 (MOD2). Thechuff
sequence is then repeated.
Ifthe modulator iswired incorrectly, themodulator willonly
produceone chuff,or nochuffat all. If anissue isdetected
during the modulator chuff test, compare the modulator
wiring and plumbing to the MC-30™controller’s electrical
system schematic and make repairs. See Figures 16 and
17.

8
2S/1M Axle Dolly-Axle
2S/2M Axle Side
4S/2M Axle Side
SELF-CONFIGURATION / CONTROL TOGGLE
When activated with a magnet or diagnostic tool, the
self-configuration feature allows for wheel speed sensor,
modulator and ABS control settings to be altered. This
is generally performed after replacement of an MC-30™
controller. See chart 5.
CAUTION: An incorrectABS configuration may cause
a fault indication or degraded ABS performance. All
MC-30™controller’s service replacement parts are
initially defaulted to 4S/2M side control and may need
to be reconfigured upon installation. Before and after
activating a self-configuration, always determine
the current ABS configuration by monitoring the
diagnostic LEDs at power-up or by activating blink
code diagnostics.
Wheel Speed Sensors
The MC-30™controller will self-configure for either two
or four wheel speed sensors. If either rear (RER) wheel
speed sensors are detected, four wheel speed sensors
will be selected. If neither rear wheel speed sensors are
detected,the MC-30™controllerwillconfigurefor twowheel
speed sensors. The MC-30™controller will default to two
ABS modulators for any four sensor configuration.
Whenconfigured fortwo wheelspeed sensors,Right Front
(RHT FRT) and Left Front (LFT FRT) wheel speed sensor
inputs must be used, even if the wheel speed sensors are
not physically located on the front axle.
Modulators
The EC-30T™controller will self-configure for either one or
twomodulators. The EC-30T™controllerwill automatically
configure for twoABS modulators if it detects Modulator 2
(MOD2) and/or either of the rear wheel speed sensors. If
MOD2 is not detected and no rear wheel speed sensors
are detected, the EC-30T™controller will configure for a
single ABS modulator.
Whenconfiguredfor asingle modulator, Modulator1(MOD
1) must be used.
ABS Control Toggle
TheMC-30™ABS controllercontrol setting canbe toggled
between Control Group A and Control Group B. When
activated,the MC-30™controllerwill toggletheABS control
between (axle control) and (dolly-axle control or side
control). Whena self-configuration occurswithout anABS
control toggle, the ABS control group does not change.
See chart 6 and chart 7.
Self-Configuration Procedure
Verify that the ECU, wheel speed sensor and ABS
modulator connectors are in place and then power the
MC-30™controller.
Determinethe currentABSconfiguration bymonitoring the
diagnostic LEDs at power-up or by activating blink code
diagnostics.
Hold a magnet on the reset location of the diagnostic
display. All of the LEDs will be on while the magnet is
held in place.
After holding the magnet in place for 20 seconds, the
LEDs will begin to roll and the MC-30™controller will self-
configurefor the numberof detectedwheel speed sensors
and modulators. If it is not desired to toggle the ABS
control, remove the magnet.
The MC-30™controller will then automatically go through
the power-up sequence and display the new configuration
on the diagnostic LEDs. Verify the newABS configuration
by monitoring the diagnostic LEDs at power-up or by
activating blink code diagnostics.
If an erroneous sensor or modulator combination is
detected during the self-configuration, fault codes are
activated when the MC-30™controller returns to normal
operating mode.
ABS Control Toggle Procedure
Toalso toggletheABScontrol, continueto holdthe magnet
in place while the LEDs are rolling, for an additional 20
seconds (total of 40 seconds). After holding the magnet in
place for 40 seconds, the LEDs will begin to rapidly flash.
At this point the MC-30™controller will toggle the ABS
control configuration. Remove the magnet.
The MC-30™controller will then automatically go through
the power-up sequence and display the new configuration
on the diagnostic LEDs. Verify the new ABS configuration
by monitoring the diagnostic LEDs at power-up or by
activating blink code diagnostics.
CHART 5 - SELF-CONFIGURATION AND ABS CONTROL TOGGLE ACTIVATION
CHART 6 - ABS CONFIGURATION AND CONTROL TOGGLE
ABS
Configuration Control Group A Control Group B
Toggle
Toggle
Toggle

9
Your trailer has two wheel speed
sensors and oneABS modulator that
is plumbed for axle control.
The MC-30™controller you have
installed is currently configured for
4S/2M side control.
Providepower tothe MC-30™controller
and verify the current configuration
using the LEDs or blink codes.
4S/2M Side
Hold magnet in place for 20
seconds.
The LEDs will begin to roll as the
installed sensors and modulators are
detected.
2S/1M Dolly-Axle
WiththeLEDs rolling,continuetohold
the magnet in place for an additional
20 seconds. (Total of 40 seconds)
The LEDs begin to flash as the ABS
control toggle activation occurs.
Remove magnet.
2S/1M Axle
Verify the new configuration using
the LEDs or blink codes.
4S/2M Side to 2S/1M Axle
CHART 7 - EXAMPLES OF SELF-CONFIGURATION AND ABS CONTROL TOGGLE (1 of 2)
Your dolly or steer axle has two
wheel speed sensors and one ABS
modulator that is plumbed for axle
control.
The MC-30™controller you have
installed is currently configured for
2S/1M axle control.
Providepower to theMC-30™controller
and verify the current configuration
using the LEDs or blink codes.
2S/1M Axle
Hold magnet in place for 20
seconds.
The LEDs will begin to roll as the
installed sensors and modulators are
detected.
2S/1M Axle
WiththeLEDs rolling,continuetohold
the magnet in place for an additional
20 seconds. (Total of 40 seconds)
The LEDs begin to flash as the ABS
control toggle activation occurs.
Remove magnet.
2S/1M Dolly-Axle
Verify the new configuration using
the LEDs or blink codes.
2S/1M Axle to
2S/1M Dolly-Axle

10
Your trailer has two wheel speed
sensors and two ABS modulators
that are plumbed for axle control.
The MC-30™controller you have
installed is currently configured for
4S/2M axle control.
Providepowertothe MC-30™controller
and verify the current configuration
using the LEDs or blink codes.
4S/2M Axle
Hold magnet in place for 20
seconds.
The LEDs will begin to roll as the
installed sensors and modulators are
detected.
Remove the magnet.
2S/2M Axle
Stop! You do not need to perform an
ABS control toggle in this case.
Verify the new configuration using
the LEDs or blink codes.
4S/2M Axle to 2S/2M Axle
CHART 7 - EXAMPLES OF SELF-CONFIGURATION AND ABS CONTROL TOGGLE (2 of 2)
Your trailer has two wheel speed
sensors and two ABS modulators
that are plumbed for side control.
The MC-30™controller you have
installed is currently configured for
4S/2M side control.
Provide power to the MC-30™controller
and verify the current configuration
using the LEDs or blink codes.
4S/2M Side
Hold magnet in place for 20
seconds.
The LEDs will begin to roll as the
installed sensors and modulators are
detected.
Remove the magnet.
2S/1M Dolly-Axle
Stop! You do not need to perform an
ABS control toggle in this case.
Verify the new configuration using
the LEDs or blink codes.
4S/2M Side to
2S/1M Dolly-Axle

11
Parameter Default Settings Available Settings
Rolling 500 revs/mile 300 to 700 revs/mile
Radius
Tone Ring 100 teeth 80, 86, 100, 120 teeth
Tooth Count
Thetire rolling radiusis defaultedto 500 revs/mileand can
be adjusted from 300 to 700 revolutions per mile. Refer to
the manufacturer’s tire specification for correct settings.
Tone ring tooth count is defaulted to 100 teeth and can be
set to 80, 86, 100 or 120 teeth.
FAULT DETECTION
The MC-30™controller contains self testing diagnostic
circuitry that continuously checks for proper operation of
the ABS components and wiring. The MC-30™controller
controlsatrailer mountedindicatorlamp toadvisethedriver
of the status of the system. The MC-30™controller may
also send the system status to the towing vehicle using
PLC communications.
When the MC-30™controller senses an erroneous system
condition, it stores the fault code in memory, activates the
indicator lamp and disables all or part of the affectedABS
functions. The faulted component is also identified on the
MC-30™controller diagnostic display.
Insome instances,the MC-30™controllerwillautomatically
reset (self-heal) the active fault code when the fault is
corrected. However, repeated occurrences of a given
fault will cause the fault code to latch. Once the fault code
is latched, a manual reset is required. Latching of faults
assiststhe technicianin troubleshootingintermittent faults.
Thefault codeis storedinthe MC-30™controller’smemory,
even when power is removed.
After repair, latched fault codes can be reset by briefly
holding a magnet on the reset location of the MC-30™
controller’s diagnostic display. Fault codes can also be
reset with blink code diagnostics or with a diagnostic
tool.
When a fault self-heals or is manually reset, the fault code
remains in fault history. Fault history can be retrieved with
blink code diagnostics or with a diagnostic tool.
MC-30™Controller ABS Partial Shutdown
Depending which fault is detected, the ABS function may
be completely or partially disabled. Even with the ABS
indicator lamp on, dual modulator configurations may still
provide some level ofABS function on wheels that are not
affected by the fault. Single modulator configurations are
completely disabled for any single fault.
ECU Fault
All functions are completely disabled. The system reverts
to normal braking.
Voltage Fault
Whilevoltage isoutof range,ABSfunctionis disabled. The
systemrevertsto normalbraking. Whenthe correctvoltage
level is restored, full ABS function is available. Operating
voltage range is 8.0 to 16.0 VDC.
OTHER CONFIGURABLE PARAMETERS
The MC-30™controller has various configurable function
parameters that can be enabled to provide the user with
additional customized features. The default settings for
these parameters are chosen by the vehicle OEM. The
configurable features include serial communications
message broadcasts, alternative lamp control, various I/O
recognition, ABS control settings and others. To ensure
that the replacement unit has the correct default settings,
reference the original part number. These settings can be
altered using a diagnostic tool. For further information,
contact Bendix or refer to your local authorized Bendix
dealer.
ODOMETER FUNCTION
The MC-30™controller’s odometer function stores the
accumulated mileage of the vehicle. The mileage will be
calculated using wheel speed sensor information. Every
1.0 mile accumulated during powered operation will be
recorded.
Mileage will only be recorded while the MC-30™controller
is powered. If stop light power is the only power source to
the MC-30™controller, correct accumulated mileage will
not be recorded.
The odometer will store vehicle mileage up to 9,999,999
miles. When the odometer mileage counter function is
full, it will latch and not record or calculate any additional
mileage.
The odometer mileage can be read using a diagnostic
tool or blink code diagnostics. Refer to the Blink Code
Diagnostics section for further information.
The odometer mileage can be cleared or reset using a
diagnostic tool. This function is password protected.
It is necessary to properly configure wheel rolling radius
and tone ring tooth count for accurate odometer mileage
to be accumulated.
Calibration of Non-Standard Wheel Sizes
TheMC-30™controller allowsfortire rollingradius andtone
ring tooth count parameters to be set for each axle using a
diagnostic tool. These adjustments may be necessary for
the MC-30™controller to accurately calculate the vehicle
velocity and odometer mileage. Wheels of the same axle
must be set to the same rolling radius and tone ring tooth
count.
Inmost cases,these parametersare setby thetrailer OEM
and do not need to be adjusted. In the case of a service
replacementunit,these parameterswillneedto beadjusted
if the default settings do not match the vehicle.
CHART 8 - WHEEL SIZE CALIBRATION FACTORS

12
MC-30™CONTROLLER DIAGNOSTIC DISPLAY
TheMC-30™controller diagnosticdisplayconsists ofseven
red fault LEDs, one green power LED and an internal
magnetic reset switch. See Figure 13 for illustration.
No diagnostic tools are needed to read the MC-30™
controller’s diagnostic display. A fault displayed on the
LEDs will always cause the ABS indicator lamp to be on.
Reading a Fault
When a fault is detected, the MC-30™controller identifies
the faulted component with the diagnostic LEDs. Awheel
speed sensor or modulator LED (SEN or MOD) may be
accompanied by wheel location LEDs. An example is
FRT-RHT-SEN. When these three LEDs are on, this is
an indication of a fault on the front axle (FRT), right side
(RHT), wheel speed sensor (SEN).
For complete explanation and troubleshooting of faults
displayed by the LEDs, go to section E, Troubleshooting.
Thered diagnosticLEDs onlyindicate activesystem faults.
When a fault self-heals or is manually reset, the LEDs are
cleared but the fault code remains in fault history. Fault
history can be retrieved with blink code diagnostics or with
a diagnostic tool.
If faults occur on multiple components, the diagnostic
LEDs will display one fault at a time. When the first fault is
repaired and the MC-30™controller is reset, the next fault
will be displayed on the LEDs.
Fault Reset
After the fault is corrected, the active fault code and LEDs
can be reset by briefly holding a magnet in place at the
RESET location of the diagnostic display. See Figure
13. All of the LEDs will be on while the magnet is held in
place. If one or more of the LEDs do not go on when the
magnet is in place, replace the EC-30T™controller. When
the magnet is removed from the reset location, only the
green VLT diagnostic LED should be on. However, if any
red LEDs are still on, active faults are still present in the
system.
Note: A self-configuration will occur if the magnet is held
at the reset location for greater than 20 seconds. Do not
hold the magnet at the reset location for longer than 10
seconds unless a self-configuration is desired.
FIGURE 13 - MC-30™CONTROLLER LED DIAGNOSTIC DISPLAY
FIGURE 14 - MC-30™CONTROLLER LED DIAGNOSTIC
DISPLAY
BLINK CODE DIAGNOSTICS
TheMC-30™controllerprovidesdiagnosticandconfiguration
functions through blink code diagnostics. Blink code
diagnostics are activated by providing constant power to
the ignition circuit and toggling the brake light power input
to the MC-30™controller.
When blink code mode is activated, the MC-30™controller
will blink the trailer mountedABS indicator lamp to display
active fault codes, fault code history, ABS configurations
andodometer mileage. Blinkcode diagnosticscan alsobe
used to reset active fault codes. See chart 9 for all blink
code functions.
Following a single display of all available messages, the
ABS indicator lamp will remain on for five seconds and
then return to normal operating mode.

13
Display MC-30™Controller Configuration
To check the ECU configuration, apply ignition power.
Apply and release the brake pedal six times. Following
activation,there willbea 5second delayfollowed byablink
code display of the MC-30™ABS controller configuration.
See chart 10.
It may be necessary to wait until after the modulator chuff
testbeforeactivating brakelightpower. Ifwheel speedsare
detected during blink code diagnostics mode, the MC-30™
controller will exit blink code diagnostics and return to
normal operating mode. Blink code diagnostics can only
be activated following a power-up, where wheel speeds
have not been detected. Blink code diagnostics must be
activatedwithin15 secondsof ignitionpowerbeing applied.
Ifbrake light poweris continuouslyapplied forgreater than
five seconds, blink code diagnostics will be disabled until
ignition power is cycled.
CHART 9 - BLINK CODE ACTIVATION
With Ignition Power Applied, Blink Code
Cycle Brake Light Power Action
3 times Display Active Fault Codes
4 times Display Fault Code History
5 times Reset Active Fault Codes
6 times Display EC-30T Configuration
7 times Display of Odometer Mileage
(If Equipped) (x1000)
CHART 10 - BLINK CODES FOR MC-30™CONTROLLER
CONFIGURATION
1st Digit Sensor
2 2 Sensors
3 4 Sensors
2nd Digit Modulators
1 1 Modulator (Dolly-Axle control)
2 1 Modulator (Axle control)
3 2 Modulators (Axle control)
4 2 Modulators (Side control)
Display Active Fault Codes
To display active fault codes, apply ignition power. Apply
and release the brake pedal three times. Following
activation,there willbea 5second delayfollowed byablink
code display of all active fault codes. See chart 11.
Display Fault Code History
To display history fault codes, apply ignition power.
Apply and release the brake pedal four times. Following
activation,there willbea 5second delayfollowed byablink
code display of all history fault codes. See chart 11.
Reset Active Fault Codes
Toreset activefault codes,apply ignitionpower. Apply and
release the brake pedal five times. Following activation,
there will be a 5 second delay followed by a blink code
message of:
1-1, (System Fully Operational - No Faults Detected)
or
Ablink code display of all remaining active fault codes.
See chart 11.
TheABS indicator lamp will stay on if active faults are still
present.
Resetting active fault codes with blink code diagnostics
does not clear information from fault history. Fault history
can be retrieved by using blink code diagnostics or a
diagnostic tool.
Display Odometer Mileage
To display the trailer odometer mileage, apply ignition
power. Apply and release the brake pedal seven times.
Followingactivation,there willbe a5second delayfollowed
by a blink code display of the odometer information
(x1000).
Example: 152,431 miles will be displayed as:
152 (x1000) or
1 blink (pause), 5 blinks (pause), 2 blinks.
Zeros will be displayed by a strobing ABS indicator lamp
twice.
Odometer mileage can not be altered with blink code
diagnostics. Complete odometer information can be
retrieved using a diagnostic tool.
BENDIX ABS DIAGNOSTIC SOFTWARE
BendixABS Diagnostic Software is an RP-1210 compliant
PC-basedprogramthatprovidestechnicianswiththehighest
level of diagnostic and control information for the MC-30™
controller. It can also be used to diagnose the EC-15™,
EC-16™, EC-17™and EC-30™tractorABS controller units.
With BendixABS Diagnostic Software, the technician can
perform full ABS diagnostics, configuration, testing and
more.
An RP-1210 compliant communication link is needed
whenconnecting a PCto the trailer’s diagnosticconnector
(J1708/J1587).
For more information on the Bendix ABS Diagnostic
Software program, or RP-1210 compliant tools, contact
Bendix or refer to your local authorized Bendix dealer.

14
CHART 11 - MC-30™CONTROLLER BLINK CODE DEFINITIONS (1 of 2)

15
CHART 11 - MC-30™CONTROLLER BLINK CODE DEFINITIONS (2 of 2)

16
READ/WRITE (SCRATCHPAD) FUNCTION
Using the BendixABS diagnostic software, OEM and fleet
service records can be permanently stored in the EC-30™
controller. Data contained in the OEM scratchpad area is
protected by a special password and can not be revised
in the field. Technician and date information must be
enteredprior to thefleet scratchpadbeing updated. Some
earlier revisions of the EC-30™controller do not support
the read/write function.
For more information on the Bendix ABS Diagnostic
Software program, or RP-1210 compliant tools, contact
Bendix or refer to your local authorized Bendix parts
outlet.
NEXIQ (MPSI) BENDIX CARTRIDGE
MPSIprovides aBendixcartridge forusewith thePro-Link®
tool. It can also be used to diagnose the EC-15™, EC-16™,
EC-17™and EC-30™tractor ABS controller units. For
more information on the Bendix diagnostic cartridge from
MPSI, contact Bendix or refer to your local authorized
Bendix dealer.
PLC DIAGNOSTIC TOOL
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.
CONTACTING BENDIX - www.Bendix.com
The Bendix on-line troubleshooting guide for the MC-30™
controller will help you determine the cause of any
conditions that may be preventing 100% performance
of your braking system. For additional troubleshooting
information on the MC-30™controller, please refer to our
literature request section.
The Bendix on-line contacts guide will make it easy for
you to find the Bendix contacts you need. From this
page, you can navigate to technical support contacts,
serviceengineers, Bendixaccountmanagers, international
contacts and more. Bendix.com is your complete Bendix
resource.
Bendix Technical Assistance Team: For direct
personal technical support, call the Bendix technical
assistance team at 1-800-AIR-BRAKE (1-800-247-2725),
Monday through Friday, 8:00 A.M. to 6:00 P.M. EST, and
follow the instructions in the recorded message.
Or, you may e-mail the Bendix technical assistance team
at: [email protected].
To better serve you, please record the following
information before calling the Bendix Tech Team:
Bendixproductmodelnumber,partnumberandconfiguration;
vehicle make and model; Vehicle configuration. (Number
of axles, tire size, etc.); System performance symptoms.
When do they occur?; What faults have been identified
using LEDs, blink codes or diagnostic tools?; What
troubleshooting / measurements have been performed?;
What Bendix service data literature do you have or need?;
Do you have access to the internet or email?
CORRECT MAINTENANCE PRACTICES
WARNING! PLEASE READ AND FOLLOW
THESEINSTRUCTIONSTOAVOIDPERSONAL
INJURY OR DEATH:
When working on or around a vehicle, the following
general precautions should be observed at all times.
1. Park the vehicle on a level surface, apply the
parking brakes, and always block the wheels.
Always wear safety glasses.
2. Stop the engine and remove ignition key when
working under or around the vehicle. When
working in the engine compartment, the engine
should be shut off and the ignition key should be
removed. Where circumstances require that the
engine bein operation,EXTREME CAUTION should
be used to prevent personal injury resulting from
contact with moving, rotating, leaking, heated or
electrically charged components.
3. Do not attempt to install, remove, disassemble
or assemble a component until you have read
and thoroughly understand the recommended
procedures. Use only theproper toolsand observe
all precautions pertaining to use of those tools.
4. If the work is being performed on the vehicle’s
air brake system, or any auxiliary pressurized air
systems, make certain to drain the air pressure
from all reservoirs before beginning ANY work
on the vehicle. If the vehicle is equipped with an
AD-IS®air dryersystem or a dryerreservoir module,
be sure to drain the purge reservoir.
5. Followingthevehiclemanufacturer’srecommended
procedures, deactivate the electrical system in a
manner that safely removes all electrical power
from the vehicle.
6. Never exceed manufacturer’s recommended
pressures.
7. Never connect or disconnect a hose or line
containing pressure; it may whip. Never remove
a component or plug unless you are certain all
system pressure has been depleted.
8. Use only genuine Bendix®replacement parts,
components and kits. Replacement hardware,
Parallel or
Serial Cable
J1708/J1587
or J1939
Lap Top
Computer
PDM (RP-1210)
FIGURE 15 - BENDIX ABS DIAGNOSTIC SOFTWARE

17
tubing, hose, fittings, etc. must be of equivalent
size, type and strength as original equipment and
be designed specifically for such applications and
systems.
9. Components with stripped threads or damaged
parts should be replaced rather than repaired. Do
not attempt repairs requiring machining or welding
unless specifically stated and approved by the
vehicle and component manufacturer.
10. Prior to returning the vehicle to service, make
certain all components and systems are restored
to their proper operating condition.
11. For vehicles with Antilock Traction Control (ATC),
the ATC function must be disabled (ATC indicator
lamp should beON) priorto performingany vehicle
maintenance where one or more wheels on a drive
axle are lifted off the ground and moving.
SERVICING THE MC-30™CONTROLLER
CAUTION! All MC-30™and EC-30T™controller service
replacement parts are initially defaulted to 4S/2M
side control and may need to be reconfigured upon
installation. An incorrect ABS configuration may
cause fault indication or degraded ABS performance.
Before and after activating a self-configuration, always
determinethe currentABSconfiguration bymonitoring
the diagnostic LEDs at power-up or by activating blink
code diagnostics.
Prior to performing service to the MC-30™controller,
always perform the following steps:
1. Turn power off.
2. Drain the air pressure from all reservoirs.
3. Remove as much contamination as possible prior to
disconnecting electrical connections and air lines.
4. Notethe MC-30™controllerassemblymounting position
on the vehicle.
REMOVING THE MC-30™CONTROLLER OR
M-30T™MODULATOR-VALVE
1. Disconnect the 30-pin ECU connector and the 3-pin
modulator connector from the MC-30™controller.
2. Remove all air lines connected to the unit.
3. Remove the MC-30™controller assembly from the
vehicle by removing the mounting bracket nuts or by
rotatingthe entireassembly counterclockwise fromthe
tank mount.
REPLACING THE EC-30T™CONTROLLER
In some cases, only the EC-30T™controller will need to
be replaced. See Figure 18. If sufficient clearance is
available, the EC-30T™controller can be removed while
the MC-30™controller assembly is still mounted to the
frame or tank. If the MC-30™controller is removed from
the vehicle, it may be lightly clamped in a bench vise
during disassembly. However, over-clamping will result
in damage, leakage, and/or malfunction. If a vise is to be
used, position the MC-30™controller so the jaws bear on
the flat area of the ECU bracket.
1. Disconnect the 30-pin ECU connector and the 3-pin
modulator connector from the MC-30™controller.
2. Remove the MC-30™controller from the vehicle if
necessary.
3. Note the EC-30T™controller position on the MC-30™
controllerassemblyand removethefour ECUmounting
bolts. The original bolts can be reused for installation
if they are in good condition. If replacement bolts are
needed, grade 5 bolts or stronger are required.
4. Reinstall the new EC-30T™controller in the original
mounting orientation. Torque the mounting bolts to
98 in. Ibs. Over-tightening the ECU bolts can cause
damage to the EC-30T™controller.
5. ThenewEC-30T™controllermayneedtobereconfigured
forproper operation. Leakage and Operational Tests
must be performed before returning the vehicle to
service.
OVERHAUL OF THE RELAY VALVE
Several maintenance kits are available when a relay
valve overhaul is necessary due to excessive leakage or
contamination of the valve. See Figure 18. Instructions
for the overhaul are provided in the replacement service
kit. For more information on Bendix valve maintenance
kits,contact Bendixor referto yourlocal authorizedBendix
dealer.
CAUTION: There are no serviceable parts in the solenoid
assemblyportionof themodulator-valveandit shouldnever
be disassembled. If troubleshooting indicates failures in
thesolenoidfunction, replacetheentire M-30T™modulator-
valve.
MC-12™MODULATOR / MCE-12 SERVICE
REPLACEMENT
The MC-30™controller is designed to be the service
replacement part for the MC-12™modulator product.
When EC-12, M-12™antilock modulator or ME-12 service
replacementpartsarerequired,theentireMC-12™modulator
assembly and pigtail harness must be replaced by an
MC-30™controller assembly and pigtail harness. When
replacing an MCE-12, the integral emergency function
(EV-2) must be replaced by a DC-4 and TR-3™valve
combination. See Figure 19 for plumbing details.
MC-30™controller kits are available to replace all
MC-12™modulator assemblies and harnesses. For more
information,contact Bendixorrefer toyour localauthorized
Bendix dealer.
CAUTION: The tank-mount MC-30™controller must not
be mounted on a frame or crossmember using the ECU
bracket holes.
1. Disconnect the power connector and wheel speed
sensors from the MC-12™modulator pigtail harness.
2. Remove all air lines connected to the unit.
3. Remove the MC-12™modulator assembly and pigtail
fromthe vehiclebyremoving themounting bracketnuts
or by rotating the entire assembly counterclockwise
from the tank nipple mount.
4. Install the new pigtail, starting at the power connector
and properly securing the harness every 18 inches to
the ECU location.
5. Next,refer totheReinstallation oftheMC-30™controller
or M-30T™modulator-valve section.

18
REINSTALLATION OF THE MC-30™
CONTROLLER OR M-30T™MODULATOR-VALVE
CAUTION! All MC-30™controller service replacement
parts are initially defaulted to 4S/2M side control and
may need to be reconfigured upon installation. An
incorrectABS configuration may cause fault indication
or degraded ABS performance. Before and after
activating a self-configuration, always determine
the current ABS configuration by monitoring the
diagnostic LEDs at power-up or by activating blink
code diagnostics.
The original mounting hardware can be reused for
installation if it is in good condition. If replacement
hardware is needed, use grade-5 5/16-18 nuts and lock
washersfor thebracketmount unitor aschedule 80(heavy
gauge steel) 1/2" nipple for the tank mount unit.
1. Position and secure the unit in the original mounting
orientation: (The exhaust port must point straight
down.)
Tank (nipple) mount unit -Install the nipplefitting into
themodulator-valve supplyport. Then rotatethe entire
assemblyinto thetank port untilsecure. Over-torquing
of the tank nipple could cause damage to the valve
body.
Frame (bracket) mount unit - Torque the mounting
nuts to 180-220 in-lbs.
2. Reconnect all air lines and plugs to the modulator-
valve assembly. Make certain that no thread sealing
materialenters thevalve. Allair linesandfittingsshould
be checked for leaks prior to returning the vehicle to
service.
3. Reconnect the ECU, modulator and sensor electrical
connectors to the unit. Apply a moderate amount of
non-conductive electrical grease to each connector
pin before reconnecting. Torque the 30-pin ECU
connector jack-screw to 15-20 in. lbs. Over-
tightening the jack-screw can cause damage to the
EC-30T™controller.
4. ThenewMC-30™controllermayneedtobereconfigured
forproper operation. Leakage and Operational Tests
must be performed before returning the vehicle to
service.
LEAKAGE AND OPERATIONAL TESTS
1. Before performing leak tests, block the wheels.
2. Fully charge the air brake system and verify proper
brake adjustment.
3. Make several trailer brake applications and check for
prompt application and release at each wheel.
4. Check the modulator-valve body and all air line
fittings for leakage by spraying each area with a soap
solution:
- Check theABS solenoid body with the trailer service
brakes fully applied. If leakage is excessive, replace
the entire M-30T™modulator-valve.
-Check the relay exhaustport and thearea around the
retaining ring with the trailer service brakes released.
A single 1" bubble within 3 seconds is permitted.
-Check the relay exhaustport and thearea around the
retainingringwith thetrailerservice brakesfullyapplied.
A single 1" bubble within 3 seconds is permitted.
If excessive leakage is detected at the relay exhaust
port, perform the following test before replacing the
M-30T™modulator-valve:
Apply the trailer spring brakes. Recheck for leakage
aroundthe relayexhaust port. Ifthe exhaustport stops
leaking, this indicates a leak between the emergency
and service sides of the spring brake chamber.
However, if the relay exhaust port continues to leak,
replace the entire M-30T™modulator-valve.
5. Applypower andmonitor theMC-30™controller power-
upsequenceto verifypropersystemoperation. Refer to
the MC-30™Controller Power-Up Sequence section.
6. Determinethe currentABSconfiguration bymonitoring
the diagnostic LEDs at power-up or by activating
blink code diagnostics. If necessary, reconfigure the
MC-30™controller using self-configuration or a
diagnostictool. Referto theSelf-Configuration/Control
Toggle section.
7. Calibrate and set odometer parameters if necessary
usingadiagnostic tool. Refertothe OdometerFunction
section.
8. When necessary, it is possible to road test the ABS
functionby makingan abruptstop froma vehiclespeed
of about 20 MPH to check for proper function. The
wheelsshould notenter aprolonged lockcondition and
ABSfunctionshouldbe audible. Itistheresponsibility of
the technician to perform this test in a safe location.
ABS WIRING
The Bendix pigtail wiring harness and connectors are
weather resistant and sealed at the connector interface.
See chart 12 for connector details and repair tools. 16
gauge GXL cable is typical. When troubleshooting ABS
wiring, some general rules should be followed where
applicable.
1. Check all wiring and connectors to ensure they are
secure and free from visible damage. Check for
evidence of wire chafing due to poor routing or poor
securing of wires. Check connectors for proper
insertion and locking. Verify that the connector leads
are properly greased with a non-conductive electrical
greasecompound. Connector terminalsmustnot show
signs of corrosion or exposure to the environment.
2. Duringwiring repair, asplice mustbe properlysoldered
or mechanically crimped and made water proof.
3. Never pierce wire insulation when checking for
continuity.
4. Donot deformindividual pinsor socketsduring probing
with a volt/ohm meter.
5. Only use the specified crimping tools when replacing
wire terminals and connectors.
6. Properly secure all wiring harness and sensor leads
when repairs are made. (every 18 inches)
7. Apply a moderate amount of non-conductive electrical
grease to each connector pin before reconnecting.

19
CHART 12 - MC-30™CONTROLLER WIRING AND COMPONENT CONNECTORS
ABS Component Connector Wire Wire Seal/ Terminal Terminal
Terminal Plug Lock Crimp Tool
MC-30™Controller
Harness
30-pin Packard
Metri-Pack
150 Series (Gray)
ABS Modulator
Connector
3-Pin Packard
Metri-Pack
280 Series
12048455
12040977
DTM06-2S-E007
(Sensor Side)
DTM04-2P
(Pigtail Side)
12103881
(18-16 GA)
12077411
(18-16 GA)
462-201-20141
(S-Side of
Connector)
Plug
12065266
12015323
(18-16 GA)
12094429 for Metri-
Pack Terminals
12155975 for Metri-
Pack Terminals
HDT-48-00
N/A
WM-2S
(Sensor Side)
WM-2P
(Pigtail Side)
12034145
460-202-20141
(P-Side of
Connector)
N/A
12014254 for Weather
Pack Terminals
12014012 for Weather
Pack Terminals
12048159
(18-16 GA)
Deutsch
DTM Series
Wheel Speed
Sensor 2-Pin
Diagnostic Port
4-Pin
Auxiliary
Port 8-Pin
DTM06-4S
(Pigtail Side)
DTM04-4P
(Remote Side / Cap)
DTM06-8S
(Pigtail Side)
DTM04-8P
(Remote Side) WM-2P (Remote Side)
WM-4P
(Remote Side)
WM-4S
(Pigtail Side)
WM-8S
(Pigtail Side)
Power Connector
(Vehicle Side)
5-Pin Packard
Weather-Pack
Power Connector
(Pigtail Side)
5-Pin Packard
Weather-Pack
MOD 2
(Pigtail Side)
3-Pin Packard
Metri-Pack
280 Series
15300015
N/A
12124580
(14-16 GA)
12124582
(14-16 GA)
Plug
12010300
12065158
15324197
15300003
DTM06-#S
DTM04-#P WM-#P WM-#S

20
FIGURE 16 - MC-30™CONTROLLER ELECTRICAL SYSTEM SCHEMATIC