BENDIX SD-13-4785 User Manual

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FIGURE 3 - EC-15
 CONTROLLER AND CONNECTOR STYLES
PACKARD 30 PIN 
CONNECTOR
DEUTSCH 14 PIN 
CONNECTORS
MOUNTING
The EC-15
 controller is available in two different mounting 
styles. One model is designed to be mounted on an antilock 
relay valve such as the  AR-1
 valve (see Service Data 
Sheet SD-13-4795). The AR-1
 valve is a modifi ed version 
of the R-12
®
 relay valve. When the EC-15
 controller is 
mounted on an antilock relay valve the resulting assembly 
receives a different designation. For example when the 
EC-15
 antilock controller is mounted on the AR-1
 valve 
the resulting assembly is known as a CR-15
 antilock 
controller relay. The other EC-15
 controller model is 
intended for bracket mounting to a frame member and is 
not attached to an antilock relay valve.
CONTROLLER INPUTS/OUTPUTS
The EC-15
 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-15
 controller both receive and deliver 
commands and information.
INPUTS
Wheel speed information is provided to the EC-15
 
controller via a wiring harness from individual wheel speed 
sensors located at or in the vehicle wheels. Working in 
conjunction with an exciter or tone ring, wheel speed 
sensors provide information to the EC-15
 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-15
 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-15
 
controller is able to simultaneously receive, and individually 
interpret, speed signals from four wheel speed sensors.
Vehicle power is supplied to the EC-15
 controller from 
the ignition switch through a fuse or circuit breaker. The 
electrical ground for the EC-15
 controller is the vehicle 
chassis.
OUTPUTS
Modulators, like the Bendix
®
 M-21
, are the means by 
which the EC-15
 antilock controller is able to modify driver 
applied air pressure to the service brakes. The modulator 
is an electrically controlled air valve that is located near