User's Manual

6
Diagnostic Blink Code Switch
A momentary switch that grounds the ABS Indicator Lamp
output is used to place the ECU into the diagnostic blink code
mode and is typically located on the vehicle’s dash panel.
Optional ABS Off-Road Switch and Indicator
Lamp Operation
Vehicle operators use an optional dash‑mounted switch to
place the Bendix
®
ESP
®
EC‑80
™
Controller 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 ESP EC‑80 Controller.
(If you need to know if a specic Bendix ESP EC‑80
Controller uses a J1939 message to operate the lamp,
contact the Bendix Tech Team. E‑mail the Tech Team
at [e-mail] (be sure to specify the ECU part
number), or call 1‑800‑AIR‑BRAKE (1‑800‑245‑2725).
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 ash 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 (also see page 8.)
The Bendix ESP system uses a dash‑mounted switch for the
operator to place the ECU into the ATC Mud/Snow mode.
Optional Hill Start/Hill Start Assist Feature
Switch and Lamp Operation (see also page 8.)
ESP Controllers use a dash‑mounted switch for the
operator to place the ECU into the hill start mode. This
feature interfaces between the transmission and the
braking system to help the driver prevent the vehicle from
rolling downhill when moving up a steep incline from a
stationary position.
With Hill Start Aid Feature option you lose the ABS
off-road function and the retarder relay output.
When the ECU is placed in the Hill Start Aid (HSA) feature
mode, the HSA Indicator Lamp will ash 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 HS/HSA
components. When engaged, the 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 Bendix ESP EC‑80 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-70X
™
Steering Angle Sensor
Bendix
®
brand Steering Angle Sensors (SAS) are used to
report 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‑70X
™
sensor.
The Bendix SAS‑70X 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
®
brand 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
®
ESP
®
EC-80
™
CONTROLLER
OUTPUTS
Bendix
®
M-40QR
™
and M-40HF
™
Pressure
Modulator Valves (PMVs)
The Bendix ESP EC‑80 Controller operates Bendix
®
M‑40QR
™
and M‑40HF
™
Pressure Modulator Valves
(PMVs) to modify the driver‑applied air pressure to the
service brakes during ABS, ATC, RSP or YC activation
(see pages 9-13). 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
ow through. This design allows for air delivery to brake
chambers in the event of electrical trouble.