SD-31-70082
Bendix® iSense™ (End-of-Life) and iSense™ Pro (Continuous) Air Disc Brake
(ADB) Electronic Control Unit (ECU) for TRACTORS
This document covers the iSense and
iSense Pro ECU for TRACTORS*

Bendix wear-sensing ECUs are designed to be
warning-only devices. The information broadcast by
the ECU should not be used to make adjustments to
the braking characteristics of the vehicle.

*Refer to SD-31-7570 on B2Bendix.com for information related to the
iSense Pro ECUs for trailer.

INTRODUCTION
The Bendix® iSense™ and iSense™ Pro Air Disc Brake
(ADB) Wear-Sensing Tractor Electronic Control Unit (ECU)
is a device designed to help improve the brake pad and
rotor life-monitoring ability of vehicles equipped with Bendix
tractor ADBs. The ECU makes use of the following types
of Bendix wear sensors:
•

End-of-Life (EOL) Wear Sensor: signals when a brake
pad has reached the end of its life

•

Continuous Wear Sensor: actively monitors the wear
life remaining percentage of each wheel-end as a
combined measurement of the inboard pad, outboard
pad, and rotor

The ECU can monitor either the EOL or continuous wear
sensor on up to eight (8) wheel-ends on a single vehicle.

The driver is always responsible for the control and
safe operation of the vehicle at all times. The Bendix
wear-sensing ECU does not replace the need for a
skilled, alert, professional driver, performing pre-trip
inspections, reacting appropriately and in a timely
manner, and using safe driving practices. Wear-sensing
ECUs do not substitute the need to perform regular
inspections and perform preventative maintenance.

IMPORTANT
Wear sensing does not replace the need for routine
inspections. Routine inspections should always be
conducted. Refer to SD-23-7541, Bendix® ADB22X®,
ADB22X-V ™ and ADB22X ®-LT Air Disc Brakes, on
B2Bendix.com for further inspection details.

HARDWARE CONFIGURATION
The ADB wear-sensing ECU is designed to work on a 12V
system and is compatible with 250k and 500k baud rate
J1939 CAN buses.

Figure 1 – ADB Wear-Sensing ECU
1

GENERAL SAFETY GUIDELINES

WARNING! PLEASE READ AND FOLLOW THESE INSTRUCTIONS
TO AVOID PERSONAL INJURY OR DEATH:

When working on or around a vehicle, the following guidelines should be observed AT ALL TIMES:
▲ Park the vehicle on a level surface, apply the ▲ Never connect or disconnect a hose or line
parking brakes, and always block the wheels.
containing pressure; it may whip and/or cause
Always wear personal protection equipment.
hazardous airborne dust and dirt particles. Wear
eye protection. Slowly open connections with
▲ Stop the engine and remove the ignition key
care, and verify that no pressure is present. Never
when working under or around the vehicle.
remove a component or plug unless you are
When working in the engine compartment,
certain all system pressure has been depleted.
the engine should be shut off and the ignition
key should be removed. Where circumstances ▲ Use only genuine Bendix ® brand replacement
require that the engine be in operation, EXTREME
parts, components, and kits. Replacement
CAUTION should be used to prevent personal
hardware, tubing, hose, fittings, wiring, etc.
injury resulting from contact with moving,
must be of equivalent size, type, and strength as
rotating, leaking, heated, or electrically charged
original equipment and be designed specifically
components.
for such applications and systems.
▲ Do not attempt to install, remove, disassemble, ▲ Components with stripped threads or damaged
or assemble a component until you have read,
parts should be replaced rather than repaired.
and thoroughly understand, the recommended
Do not attempt repairs requiring machining or
procedures. Use only the proper tools and
welding unless specifically stated and approved
observe all precautions pertaining to use of those
by the vehicle and component manufacturer.
tools.
▲ Prior to returning the vehicle to service, make
▲ If the work is being performed on the vehicle’s
certain all components and systems are restored
air brake system, or any auxiliary pressurized air
to their proper operating condition.
systems, make certain to drain the air pressure ▲ For vehicles with Automatic Traction Control
from all reservoirs before beginning ANY work
(ATC), the ATC function must be disabled (ATC
on the vehicle. If the vehicle is equipped with
indicator lamp should be ON) prior to performing
®
®
®
a Bendix AD-IS air dryer system, a Bendix
any vehicle maintenance where one or more
DRM™ dryer reservoir module, a Bendix® AD-9si®,
wheels on a drive axle are lifted off the ground
AD-HF®, or AD-HFi® air dryer, be sure to drain the
and moving.
purge reservoir.
▲ The power MUST be temporarily disconnected
▲ F o l l o w i n g t h e v e h i c l e m a n u f a c t u r e r ’s
from the radar sensor whenever any tests USING
recommended procedures, deactivate the
A DYNAMOMETER are conducted on a vehicle
electrical system in a manner that safely removes
equipped with a Bendix® Wingman® system.
all electrical power from the vehicle.
▲ Never exceed manufacturer’s recommended
pressures.
▲ You should consult the vehicle manufacturer's operating and service manuals, and any related literature,
in conjunction with the Guidelines above.

2

ECU MOUNTING

SAE J1939 SERIAL COMMUNICATIONS

Bendix Air Disc Brake (ADB) wear-sensing Electronic
Control Units (ECUs) can be mounted within the cab
or mounted on the rear of the chassis away from any
heat sources and is compatible with either continuous or
End-of-Life (EOL) wear sensors. The ECU connector
should be installed only by hand until it clicks into place. The
ECU has two (2) through-hole mounting tabs to be used
for mounting. Refer to Original Equipment Manufacturer
(OEM) documentation regarding mounting methods and
torques.

A Controller Area Network (CAN) data link (SAE J1939) is
provided for communication. This link is used for various
functions, including broadcasting the brake pad and rotor
life remaining and circuit diagnostic messages.

®

To ensure the product performs as intended and to prevent
corrosion, all unused pin locations in the ECU connectors
must be plugged and receive any necessary protection
from moisture, etc. The ADB wear-sensing ECU utilizes a
connector from the Deutsch® DT product family.

SOFTWARE CONFIGURATION
Bendix ADB wear-sensing ECUs are not re-configurable
and are sold with a pre-configured software set that is
identified by a part number. Refer to B2Bendix.com for the
correct part number.

ELECTRONIC CONTROL UNIT (ECU) INPUTS
AND OUTPUTS
The ADB wear-sensing ECU has one (1) ignition power
and one (1) ground input and is designed to operate at a
nominal supply voltage of 12V. The ignition power input
is the power source for the ECU and should be supplied
through a 5-amp fuse. The operating voltage range is 9.0V
to 18.0V.

IMPORTANT
ECU operation is not guaranteed outside of the
operating range.

ECU WIRING HARNESS
Bendix does not provide the wiring harness that connects
to the ECU. It is the responsibility of the OEM to incorporate
the wear-sensing ECU wiring harness into their vehicle
harness. The minimum wire gauge for connectors is
20 AWG. The ECU connector should be secured by
hand until the connector clicks into place. Refer to the
Troubleshooting: Electronic Control Unit (ECU) Wiring
Harness Connectors section of this document.

The wear-sensing ECU utilizes SAE J1939 CAN protocol
to communicate brake pad and rotor wear status. The
ECU utilizes PGN 65196 - Wheel Brake Lining Information
message to broadcast brake pad and rotor wear information.

DIAGNOSTIC TROUBLE CODES (DTCs)
FOR CONTINUOUS WEAR SENSORS
If an issue is detected with one of the continuous wear
sensors, a DTC will be broadcast to indicate what kind
of failure that sensor is experiencing. All other wear
sensors should maintain normal function. Refer to the
Troubleshooting section for more information.

END-OF-LIFE WEAR (EOL) SENSOR
EOL wear sensors are clipped onto the inboard and
outboard pad of the wheel end. The sensor is a wearable
component that is to be replaced with each pad change.

CONTINUOUS WEAR SENSOR
Continuous wear sensors provide a combined measurement
(as a percentage) of the inboard and outboard brake pads
plus the remaining rotor thickness on each wheel-end ADB.
The sensor is incorporated into the ADB for wear sensing
from the factory. The calibrated wear sensor provides a
voltage output to the ECU. This signal is then converted to
a percentage and broadcast over the J1939 CAN bus. The
continuous wear sensor functions on a 5V supply voltage.
If the sensor outputs a voltage signal of less than 4V, the
brake wear life remaining is in the “good” range. If the
sensor outputs a voltage signal of greater than or equal to
4V, the brake wear life remaining is considered to be “worn.”

IMPORTANT
Use of this sensor does not substitute the need for
routine inspection and maintenance.
NOTE: Request of ADB wear sensing must be specified
at the time of order, as continuous wear sensors cannot
be installed after the caliper has already been assembled.

SENSOR POWER AND GROUND
The ECU supplies three (3) 5V power and ground outputs to
be utilized by the continuous wear sensor. Refer to Table 2.

3

PGN

65196

65216

PARAMETER
GROUP
LABEL

Wheel
Brake Lining
Remaining
Information

Service
Information

ACRONYM

EBC4

SERV

SPN

SPN LABEL

DATA RANGE

ECU AXLE
CONFIGURATION
2
AXLE

3
AXLE

4
AXLE

1099

Front Axle, Left Wheel

2% (EoL) or 100%
Continuous: 0% to 100%

X

X

X

1100

Front Axle, Right Wheel

2% (EoL) or 100%
Continuous: 0% to 100%

X

X

X

1101

Rear Axle #1, Left Wheel

2% (EoL) or 100%
Continuous: 0% to 100%

X

X

X

1102

Rear Axle #1, Right Wheel

2% (EoL) or 100%
Continuous: 0% to 100%

X

X

X

1103

Rear Axle #2, Left Wheel

2% (EoL) or 100%
Continuous: 0% to 100%

X

X

1104

Rear Axle #2, Right Wheel

2% (EoL) or 100%
Continuous: 0% to 100%

X

X

1105

Rear Axle #3, Left Wheel

2% (EoL) or 100%
Continuous: 0% to 100%

X

1106

Rear Axle #3, Right Wheel

2% (EoL) or 100%
Continuous: 0% to 100%

X

911

Service Component Identification

Not Broadcast (or 15)

X

X

X

Table 1 – Communication

COMMUNICATION

DRIVER WARNING DEVICES

The ADB wear-sensing ECU can utilize all eight (8) SPNs
of PGN 65196 correlating to the front axle, rear axle #1,
rear axle #2, and rear axle #3 depending on the ECU axle
configuration. Refer to Table 1.

Individual OEMs are responsible for integrating this
information into their dash. OEMs shall follow those rules
laid out in Federal Motor Vehicle Safety Standards (FMVSS)
for warning light operation, symbol, and color for brake pad
and rotor wear.

Refer to Table 5 for further information on SPN/FMI.

IMPORTANT
The ADB wear-sensing ECU may broadcast the “Service
Component Identification” message with the number
“15” if any wheel position is below 10% life remaining
or there is a Diagnostic Trouble Code (DTC) present.
That message will not stop broadcasting until all wheel
positions are above 15% life remaining and there are
no DTCs active.

4

TROUBLESHOOTING
ECU DIAGNOSTICS

USING PC-BASED DIAGNOSTICS

The ADB wear-sensing ECU contains self‑testing diagnostic
circuitry that continuously checks for the normal operation of
external wear-sensing components and wiring. Diagnostics
are only available on units configured for continuous
wear sensors. DTCs only pertain to Bendix® iSense™ Pro
(continuous wear-sensing) applications. Bendix® iSense™
End-Of-Life (EOL) applications will not broadcast DTCs.

ACom Diagnostic Software is an RP-1210-compliant
PC-based diagnostic software program. With ACom
Diagnostic Software, maintenance personnel can:

ACTIVE DTCs
When a DTC is detected, the ADB wear-sensing ECU
performs the following:
1. The ECU places the appropriate DTC information in
the ECU memory.
2. The ECU communicates the appropriate DTC
information over the serial communication diagnostic
link as required.

ACTIVE DTC MODE
All active DTCs may be retrieved using a hand‑held
or PC‑based diagnostic tool, such as Bendix ® ACom®
Diagnostic Software.

•

btain Diagnostic Trouble Code (DTC) information
O
(both active and inactive DTCs)

•

Retrieve event history

•

Clear inactive DTCs and event history

•

Verify Electronic Control Unit (ECU) configuration

•

Perform system and component tests

•

Read/write customer information in the scratch pad

•

Save and print information

•

Receive troubleshooting assistance

PC-based diagnostic tools attach to the vehicle diagnostic
connector. See Figure 2.
When using ACom Diagnostic Software to diagnose the
Air Disc Brake (ADB) wear-sensing ECU, the computer’s
serial, parallel, or USB port needs to be connected to
the vehicle’s diagnostic connector. For more information
and to download ACom Diagnostic Software, visit
B2Bendix.com.

INACTIVE DTC MODE
The ADB wear-sensing ECU stores past DTCs in its
memory. The record is commonly referred to as “event
history.” When an active DTC is cleared, the ECU stores
it in the event history memory as an inactive DTC. Inactive
DTCs and event history may be retrieved and cleared
by using a PC-based diagnostic tool, such as ACom
Diagnostic Software.

Figure 2 – Typical Vehicle Diagnostic Connector

5

WIRING HARNESS CONNECTOR PIN
ASSIGNMENTS

TECHNICAL ASSISTANCE

The ECU utilizes one (1) Deutsch connector for wire
harness connections. See Figure 3 and refer to Table 2.

For additional assistance, the Bendix Tech Team can be
reached by email at [email protected] or by phone
at 1-800-AIR-BRAKE (1-800-247-2725), option 2. Bendix
Tech Team representatives are available Monday through
Thursday, 8:00 a.m. – 6:00 p.m., and Friday, 8:00 a.m. –
5:00 p.m. ET.

All unused pin locations must be populated by the
appropriate wire plug.

Figure 3 – Pin Assignments
PIN

DESIGNATION

PIN

DESIGNATION

DESIGNATION

1

Ignition Power

7

Sensor Signal, Front Axle Left

13

Sensor Signal, Rear Axle #3 Left