Bendix Commercial Vehicle Systems EC-14 ANTILOCK CONTROLLER 5/04 - Manual (Page 3)

3
M-12 ™
MODULATOR
ASSEMBLY
resulting assembly receives a different designation. For
example, when the EC-14
™ antilock controller is mounted
on the M-12 ™ modulator the resulting assembly is known
as a MC-14 ™ modulator controller (see Figure 3).
EC-14 ™ CONTROLLER INFORMATION
INPUTS AND COMMAND OUTPUTS
GENERAL
The EC-14 ™ controller receives information from several
components in the antilock system and, based on these
inputs, issues commands or delivers information. Some
portions of the EC-14
™ controller both receive and deliver
commands and information.
INPUTS
Wheel Speed Information is provided to the EC-14 ™
controller via a wiring harness from individual speed sensors
located in the trailer wheels or axle housing. Working in
conjunction with an exciter or tone ring, the speed sensors
provide information to the EC-14
™ controller in the form of an
AC signal which varies in voltage and frequency as the speed
of the wheel increases or decreases.
The EC-14 ™ controller is designed to receive wheel speed
information, from various wheel speed sensor models, at
the rate of 100 pulses per wheel revolution. The EC-14
™
controller is able to simultaneously receive, and individually
interpret, speed signals from four wheel speed sensors (2
axles).
Vehicle Power is supplied to the EC-14 ™ controller from
the from the ignition switch through a fuse or circuit breaker.
The electrical ground for the EC-14
™ controller is the vehicle
chassis.
A Stop Light Switch connection to the EC-14 ™ controller
is provided and serves to “signal” the EC-14 ™ controller of all
brake applications. Although the stop light switch connection
enhances the EC-14
™ antilock controller performance, a loss
of the stop light switch “signal” will not prevent antilock
operation.
OUTPUTS
Modulators, like the Bendix ® M-12 ™ and M-21 ™ or M-22 ™ ,
are the means by which the EC-14 ™ antilock controller is
able to modify driver applied air pressure to the service
brakes. The EC-14
™ controller is able to simultaneously
and independently control two modulator assemblies.
FIGURE 3 - MC-14 ™ MODULATOR CONTROLLER ASSEMBLY
EC-14 ™ CONTROLLER
DIAGNOSTIC
WINDOW
MODULATOR
EXHAUST
WIRE HARNESS
CONNECTOR
SERVICE
PORT
SOLENOID
EXHAUST
SUPPLY (2)
DELIVERY PORTS (4)