SD-03-1189
Bendix® Intellipark® Electronic Park Brake (EPB) System

Dash Electronic Control Unit (DECU)
Towing Vehicle Variant
(similar to the Bendix® MV-3® Dash Control Valve)

Dash Electronic Control Unit (DECU)
PP-Left Non-Towing Vehicle Variant
(similar to the Bendix® PP-DC® Park Control Valve)

Dash Electronic Control Unit (DECU)
PP-Right Non-Towing Vehicle Variant
(similar to the Bendix PP-DC Park Control Valve)
NOTE: Both towing and non-towing units may have various switch configurations (vertical and horizontal) and
mounting brackets. The DECU PP variant is available in both PP-Right and PP-Left configurations.
Figure 1 – Bendix® Dash Electronic Control Unit (DECU) Variants

1

INTRODUCTION
The Bendix® Intellipark® Electronic Park Brake (EPB)
System provides parking capability for commercial vehicles
(tractors, trucks, and buses) that utilize air brakes. It is
available in various models to support a wide range of
applications. The system contains the Dash Electronic
Control Unit (DECU), the Park Valve Module (PVM), and
an integrated display – provided by the vehicle Original
Equipment Manufacturer (OEM) or by Bendix.
The Intellipark EPB system functionally replaces previous
Bendix ® park brake dash valves such as the MV-3 ®
dash control valve, the Bendix® PP-1® control valve,
and the Bendix ® PP-DC ® park control valve with an
electromechanical valve and an electronic controller
which includes a driver interface. The Intellipark EPB
system provides many of the same features and functions
as manual park brake dash valves, but also provides
advanced features and functions not available in the
previous park brake valves.
Proper integration of the Intellipark EPB system by the
vehicle OEM provides the following vehicle operational
and driver assistance features:

2

•

A solo vehicle (bobtail tractor, solo truck, or bus) or
combination vehicle can be parked and unparked

•

A towing unit with towing provisions can couple to, and
uncouple from, a towed unit (power unit brakes to be
released while trailer brakes are set)

•

A power unit with towing provisions can charge a towed
unit(s) while parked

•

A power unit with towing provisions can be operated
as a solo vehicle (bobtail)

•

The driver can determine if air is being delivered to
the parking brakes

•

The driver can determine availability of park system

•

Rollaway Mitigation may potentially help mitigate a
vehicle rollaway when the driver leaves the vehicle
unparked

•

Power Unit Park Brake Release Interlock may
potentially help mitigate the release of the park brakes
without a driver in control of the vehicle

•

Towing Vehicle/Auto Trailer Brake Release may
provide the ability to detect some situations where the
driver attempts to drive a combination vehicle with the
trailer(s) parked

•

Exhaust-at-Speed may potentially help mitigate the
possibility that accidental switch operation will cause
the spring brakes to apply while driving

NOTE: The availability of operational and driver assistance
features depends on the vehicle OEM.

VEHICLE OPERATION FEATURES

The Intellipark EPB system cannot detect issues with
other components of the park brake system, such as
the spring brake chambers. Accordingly, drivers and
maintenance personnel must perform inspections and
maintenance on the park brake system in accordance
with established procedures. For proper operation of
the Intellipark EPB system, all other components of the
park brake system must be functioning as designed.

•

Towing Vehicle – Single-Button Park: The Intellipark
EPB system provides the ability to park all units of a
combination vehicle with a single input. This feature
is similar to the single-button park feature of the MV-3
dash control valve. Upon pulling the yellow switch
of the DECU, the PVM will exhaust the air from the
power unit and towed unit channels. The behavior of
this feature is modified if the vehicle is moving. Refor
to the section titled Exhaust-at-Speed for more details.

•

Towing Vehicle – Independent Trailer Air Control:
The Intellipark EPB system provides the ability to charge
or evacuate the trailer supply (red) line independent of
the state of the power unit spring brakes. This feature
allows operation of a vehicle with towing provisions
as a solo vehicle, supports coupling and uncoupling
operations, and allows trailer emergency brake control.
Upon pulling the red switch of the DECU, the PVM
will exhaust the air from the towed unit channel, with
no change in state of the power unit (yellow) channel.
Upon pushing the red switch of the DECU, if the trailer
air charge interlocks have been satisfied, the PVM will
deliver air to the towed unit channel, with no change
in state of the power unit (yellow) channel.

•

Towing Vehicle – Independent Trailer Air Charge
Interlock: The Intellipark EPB system provides the
ability to restrict the air charge function of the trailer
based on inputs from the vehicle, including the service
brakes and ignition switch. This feature is intended
to potentially help mitigate the possibility of release
of the trailer park brakes without a driver in control of
the vehicle, while allowing the trailer(s) to be charged
with the power unit parked. This functionality supports
coupling and uncoupling operations, including pre-trip
inspections for some types of combination vehicles.

NOTE: Refer to the applicable operator's manual on
B2Bendix.com for further details on vehicle features and
interlocks.

Improper use of the Intellipark EPB system can result
in an unsafe park state, causing property damage,
serious injuries, and/or death. Drivers must be
responsible for the safe operation of the vehicle at all
times. The Intellipark EPB system does not replace the
need for a skilled driver, reacting appropriately and
in a timely manner, and using safe driving practices.

IMPORTANT
Bendix®-brand Electronic Control Units (ECUs) are
not designed to store data for purposes of accident
reconstruction and Bendix® ACom® Diagnostic Software
is not intended to retrieve data for purposes of accident
reconstruction. Bendix makes no representations as to
the accuracy of data or video retrieved and interpreted
from ECUs for purposes of accident reconstruction.
Bendix does not offer accident reconstruction services
or interpretation of stored data. Bendix ECUs are not
protected from fire, loss of power, impact damage, or
other conditions that may be sustained in a collision
situation and may cause data to be unavailable or
irretrievable.

3

•

Exhaust-at-Speed: The Intellipark EPB system
provides functions to help the driver achieve a controlled
stop when the yellow or red switch is pulled while the
vehicle is in motion, while at the same time potentially
helping mitigate the possibility that accidental switch
operation will cause the spring brakes to apply while
driving. This feature provides a short, programmable
delay before an exhaust event is initiated when the
driver pulls the yellow or red switch when the vehicle
is in motion. The delay time is dependent on vehicle
speed; at low speeds, no delay is initiated.
his function is intended to fulfill emergency brake
T
operation requirements while reducing the likelihood of
unintended activations of the spring brakes at normal
on-road speeds. In an emergency situation where
the service brakes are not available while driving,
if activating the spring brakes is needed to reduce
vehicle speed, pull and hold the parking (yellow) and/
or trailer emergency (red) switch until the desired
spring brakes have been activated. Pull-and-hold of
the parking (yellow) switch will activate the spring
brakes of the tractor and trailer. Pull-and-hold of the
trailer emergency (red) switch will activate the spring
brakes of the trailer.
he exhaust-at-speed feature provides an automatic
T
release of the spring brakes once the driver has
released the switch and it has returned to its neutral
position (dependent on the speed of the driver since
at low speeds the vehicle will be parked).
nce an exhaust-at-speed event has been initiated,
O
the driver may push the red and/or yellow switch as
needed to indicate intent to charge the spring brakes.
Pushing the yellow switch will charge only the tractor
channel, while pushing the red switch will charge only
the trailer channel. This would only be necessary at low
speeds when the system would fully park the vehicle.

4

Never attempt to test the exhaust-at-speed feature
or use it in the course of normal driving. This feature
is intended for use only in emergency situations
where the tractor and/or trailer service brakes are not
available while driving. Testing the exhaust-at-speed
feature can only be safely performed on a test track
with a trained driver. Failure to follow this warning
could lead to vehicle damage, property damage, injury,
and/or death. Drivers and maintenance personnel must
read and understand the contents of the Intellipark
owner's manual before operating a vehicle equipped
with the Intellipark EPB system.
Activation of the spring brakes while driving should
only be performed by qualified drivers in emergency
situations where the safest action available to the
driver is to activate the spring brakes while driving.
Activation of the spring brakes while driving can result
in a degradation of vehicle control, causing property
damage, serious injuries, and/or death.
The Bendix Intellipark EPB system is designed
with features to lessen the possibility of accidental
activation of the spring brakes while driving. The driver
must pull and hold the switch for 0.25 seconds [a
vehicle OEM configurable delay] to activate the spring
brakes at road speeds. This delay allows emergency
brake control while protecting against accidental
activation of the spring brakes.

•

Rollaway Mitigation: The Intellipark EPB system's
Rollaway Mitigation feature is intended to potentially
help mitigate the possibility of a roll-away resulting
from the driver failing to park the vehicle. The
Intellipark EPB system provides the ability to detect
some situations where the vehicle is unparked and
the driver is not present in the driver’s seat, based on
inputs from the vehicle including the cab doors, service
brakes, and engine throttle pedal. In response to a
predetermined sequence of inputs, Rollaway Mitigation
may automatically set the parking brake.
he Rollaway Mitigation feature is not intended to be
T
a primary automation feature. In all cases, the driver
remains responsible for activating the park switch for
each drive cycle.

Drivers and maintenance personnel must not rely on
the Intellipark EPB system to automatically park the
vehicle. Drivers continue to be responsible for safe
and proper operation of the vehicle.

•

Power Unit Park Brake Release Interlock: The
Intellipark EPB system provides the ability to restrict
the release of the parking brakes based on inputs from
the vehicle including the cab doors, service brakes, and
ignition switch. This feature is intended to potentially
help mitigate the possibility of unauthorized operation
of the vehicle or release of the park brakes without a
driver in control of the vehicle.

•

Towing Vehicle: Auto Trailer Brake Release: The
Intellipark EPB system provides the ability to detect
some situations where the driver attempts to drive a
combination vehicle with the trailer(s) parked, based on
inputs from vehicle speed data, powertrain data, engine
throttle pedal, service brakes, and measurement
of the air pressure in each Intellipark channel. In
response to these inputs, the Intellipark EPB system
will automatically charge the trailer channel, thereby
releasing the trailer parking brakes if the parking brake
system downstream of the Intellipark valve is healthy.
his feature is not intended to be a primary automation
T
feature. In all cases, the driver remains responsible
for pressing the trailer charge switch at the beginning
of each drive cycle. The Auto Trailer Brake Release
feature – if enabled (refer to the vehicle OEM) – will
activate every time the conditions are met unless the
system is in bobtail mode.

Under certain conditions, the Intellipark EPB system
can automatically release the trailer park brakes.
Drivers and maintenance personnel must read and
understand the contents of the Intellipark owner's
manual before operating an Intellipark-equipped
vehicle.
NOTE: The availability of operational and driver assistance
features depends on the vehicle OEM.

he standard configuration of this feature inhibits the
T
release of the power unit spring brakes unless the
ignition is on, the cab doors are closed, the driver’s
foot is on the service brake, and – if applicable – the
transmission shifter is in the non-park position (verify
with the vehicle OEM).

5

SYSTEM COMPONENTS
The Intellipark EPB system is designed to operate with
the DECU and PVM. Substitution of either component is
not permitted. Additionally, the system also requires an
integrated display. The integrated display may be provided
by Bendix, or the vehicle OEM may choose to use the
instrument cluster or another existing integrated display
on the vehicle to perform the necessary functions.
•

DECU – Dash Electronic Control Unit: The DECU
is an ECU with an integrated display with a pushpull switch for the power unit (yellow) channel, and if
needed, a similar push-pull switch for the towed unit
(red) channel. The DECU interprets switch motion
into driver intent. Based on that input and other inputs
from the vehicle (via discrete I/O or J1939 CAN),
it activates solenoid valves to produce the desired
pneumatic response. NOTE: Units may have various
switch orientations (horizontal or vertical) and mounting
brackets. As shown in Figure 2, the DECU PP variant
is available in both PP-Right and PP-Left variants.

DECU Towing Vehicle Variant
(similar to the MV-3 Dash Control Valve)

DECU PP-Left Non-Towing Vehicle Variant
(similar to the PP-DC Park Control Valve)
Obstruction of the motion of the Intellipark switches
may prevent proper operation of the spring brakes.
Failure of the spring brakes to operate properly may
cause undesired vehicle behavior such as a roll-away,
resulting in property damage, serious injuries, and/
or death.
he switches must only be used for operating the
T
spring brakes of the vehicle. Under no circumstances
should the driver or others use the Intellipark EPB
system switches as a hook, tray, support, holder, or
for another purpose that could cause their accidental
activation. Further, under no circumstances should
the driver or others use the Intellipark switches as a
handle, grab point or step point, or apply more than
normal finger force to the switches. While the Intellipark
switches are designed to withstand the commercial
vehicle environment, damage may occur if excessive
force is applied. The vehicle operator should move the
switches using only their fingers. Using feet, shoes,
tools, hooks, straps, strings, additional levers, or
other objects is not necessary and may damage the
Intellipark switches.

6

DECU PP-Right Non-Towing Vehicle Variant
(similar to the PP-DC Park Control Valve)

Figure 2 – DECU Variants

•

PVM – Park Valve Module: The PVM is an
electromechanical valve assembly with a solenoidpiloted, pneumatically stable valve for each channel.
The pneumatically stable valve is spring biased, much
like the MV-3 dash control valve, which provides a
mechanical trip function on low reservoir pressure. The
valve module also contains a duplex single-check valve
to isolate the primary and secondary supply air, and a
pressure transducer for each channel to allow direct
measurement of the delivery pressure. See Figure 3
for both PVM configurations.

Accumulation of road debris on the PVM may cause
blockage of the PVM exhaust ports. If the exhaust
ports are blocked, some valve functions may be
compromised, leading to undesirable performance of
the park system. Undesirable performance of the park
system may cause property damage, personal injury,
and/or death.

Part Number Label

Mounting Hole

Power Vehicle
Exhaust Port
Power Vehicle
Delivery Port

Secondary Supply Port

Power Vehicle
Electrical Connector
Primary Supply Port

Power Vehicle
Pressure Sensor

Park Valve Module (PVM)
Non-Towing Variant

Part Number Label

Mounting Hole

Secondary
Supply Port

Towed Vehicle
Exhaust Port

Power Vehicle
Exhaust Port

Towed Vehicle
Electrical Connector

Power Vehicle
Delivery Port

Towed Vehicle
Delivery Port

Towed Vehicle
Pressure Sensor

OE and service new Bendix
PVMs contain ribs on the body as
shown above. These ribs identify
the PVM as a genuine Bendix
product. If the OE or service new
PVM does not contain these ribs,
it is not a genuine Bendix product.

Power Vehicle
Electrical Connector

Park Valve Module (PVM)
Towing Vehicle Variant

Primary Supply Port
Power Vehicle
Pressure Sensor

Figure 3 - Park Valve Modules (PVM)
7

Operational Test

Tractor Switch (Yellow)

or information on dash valve trip pressures, refer to
F
TCH-003-051, Bendix Dash Valve Trip Pressure/DOT
Inspections, on B2Bendix.com.

1. W
ith the engine running, allow the supply pressure
to build to at least 120 psi. Satisfy all interlocks
as defined by the vehicle OEM, then push the
yellow switch. The system should deliver air to
the tractor (the brakes should release) and the
LEDs on the yellow switch should turn off.
2. Allow the supply pressure to build back up to at
least 120 psi. With all interlocks still satisfied,
push both switches and allow the tractor and
trailer brakes to release.
3.
Once the brakes have released, pull the red
switch. The tractor should remain delivered with
both LEDs off and the trailer switch should not be
delivering air. The trailer should now be parked,
and both LEDs should be off.

Trailer Switch (Red)
1. K
ey on the vehicle and monitor the DECU LEDs.
NOTE: Any blinking LEDs are indicative of a
Diagnostic Trouble Code (DTC) and will need to
be diagnosed and repaired prior to continuing.
2. Increase the supply pressure to 120 psi, satisfy
all interlocks defined by the vehicle OEM, and
push the red switch. The system should deliver
air to the trailer and the LEDs on the red switch
should turn off.