BENDIX SD-13-4834 User Manual

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)

The MC-30

™

 controller has been designed to replace the 

MC-12

™

 modulator as the standard Bendix trailer ABS 

controller assembly for OEM and aftermarket installations.  
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

™

 

controller has a 30-pin electrical connector and the 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.

The MC-30

™

 controller tank-mount assembly is mounted by 

using a schedule 80 (heavy gauge steel) 1/2" nipple directly 
between the trailer supply tank and the MC-30

™

 modulator-

valve supply port.  A tank with a reinforced port must be used.  
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.

The MC-30

™

 controller bracket mount assembly is mounted 

directly to the trailer frame rail or 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.

Effective March 1, 2001 all towed vehicles must transmit a 
signal to control an in-cab trailer ABS indicator lamp.  Trailers 
built after this date will transmit the status of the trailer ABS unit 
over the ignition power wire (blue wire of the J560 connector) 
using Power Line Carrier (PLC) communications.

The PLC signal is usually broadcast by the trailer ABS ECU.  
The application of PLC technology for the heavy vehicle 
industry is known as PLC4Trucks.  MC-30

™

 controller 

models with PLC will support communication in accordance 
with SAE J2497.

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 

can be identifi ed by the individual part number label and pin 
stamp on the EC-30T

™

 controller housing.  On PLC units, 

the PLC function can be disabled with a diagnostic tool.  

  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

The EC-30T

™

 is a plastic electronic controller with a 

single 30-pin electrical connector. The EC-30T

™

 controller 

enclosure is fi lled 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.