Bendix Commercial Vehicle Systems EC-60 ESP CONTROLLERS ADV - Manual (Page 6)

6
Optional ABS Off-Road Switch and Indicator
Lamp Operation
Advanced Bendix EC-60 controllers use an optional dash-
mounted switch for the operator to place the ECU into the
ABS off-road mode. See "Optional ABS Off-Road Mode"
on page 10 for further details. In some cases, ECUs may
also be put into the ABS off-road mode by one of the other
vehicle control modules, using a J1939 message to the
Bendix EC-60 controller.
(If you need to know if this Bendix EC-60 controller uses
a J1939 message to operate the lamp, e-mail ABS@
bendix.com, specifying the ECU part number, or call
1-800-AIR-BRAKE and speak to the Bendix TechTeam.)
WARNING
: The ABS off-road mode should not be
used on normal, paved road surfaces because vehicle
stability and steerability may be adversely affected. When
the ECU is placed in the ABS off-road mode, the ABS
Indicator Lamp will flash constantly (at a rate of once per
2.5 seconds) to notify the vehicle operator that the off-road
mode is active.
Optional ATC Mud/Snow (Off-Road) Switch and
Indicator Lamp Operation (see also page 8 .)
Advanced controllers use a dash-mounted switch for the
operator to place the ECU into the ATC Mud/Snow mode.
Optional Hill Start Feature Switch and Indicator
Lamp Operation (see also page 8 .)
Advanced controllers use a dash-mounted switch for the
operator to place the ECU into the Hill Start Assist (HSA)
mode. HSA interfaces between the transmission and
braking system to help the driver prevent the vehicle from
rolling downhill when moving up a steep incline from a
stationary position.
WARNING : With HSA option you lose the ABS off-
road function and the retarder relay output.
When the ECU is placed in the HSA off-road mode, the
HSA Indicator Lamp will flash constantly (at a rate of once
per 2.5 seconds) to notify the vehicle operator that the HSA
mode is active. The ECU receives J1939 messages from
the transmission to engage the HSA components. When
engaged, the HSA system applies 44 psi to the rear brakes
for three (3) seconds then releases. This function is totally
controlled by the automatic transmission.
Stop Lamp Switch (SLS)
The Advanced Bendix EC-60 controller monitors the
vehicle stop lamp status. Certain vehicle functions, such
as ATC and All-Wheel Drive (AWD), use the status of the
stop lamp to determine when the driver makes a brake
application. This can be provided to the ECU via J1939
communications, or hardware input.
Brake Demand Sensors
The brake demand sensors provide the controller with an
indication of driver-applied brake pressure. One is installed
in the primary air brake circuit, and another is installed in
the secondary air brake circuit.
Load Sensor
The load sensor provides the controller with an indication
of the vehicle load. It is typically installed in one of the
suspension air bags.
Bendix ® SAS-60 ™ Steering Angle Sensor
The Steering Angle Sensor (SAS) is used to provide driver
steering input to the controller. It reports the steering
wheel position to the controller utilizing a dedicated serial
communications link that is shared with the Yaw Rate
sensor. The controller supplies the power and ground
inputs to the Bendix SAS-60 sensor.
The Bendix SAS-60 sensor is available with two different
styles of wire harness connectors. (See Figure 4.)
Bendix ® YAS-60 ™ or YAS-70x ™ Yaw Rate/Lateral
Acceleration Sensors
Bendix yaw rate/lateral acceleration sensors are used
to provide the controller an indication of vehicle lateral
acceleration and rotation around the vertical axis. This
information is provided to the controller utilizing a dedicated
serial communications link that is shared with the Bendix
SAS-60 sensor. The controller supplies the power and
ground inputs to the yaw rate sensor.
BENDIx ® EC-60 ™ CONTROLLER OUTPUTS
Bendix ® M-32 ™ and M-32QR ™ Pressure
Modulator Valves (PMV)
The Bendix M-32 and M-32QR pressure modulator valves
(PMV) are operated by the Bendix EC-60 controller to
modify driver applied air pressure to the service brakes
during ABS, ATC, RSP or YC activation (See page 3).
The PMV is an electropneumatic control valve and is the
last valve that air passes through on its way to the brake
chamber. The modulator hold and release solenoids are
activated to "modulate" or "control" the brake pressure
during an antilock braking event. The hold solenoid is
normally open and the release solenoid is normally closed,
such that the PMV nominally allows air to flow through.
This design allows for air delivery to brake chambers in
the event of electrical trouble.
The Advanced Bendix EC-60 controller also utilizes an
additional PMV for control of the trailer service brakes
during stability interventions.