BENDIX EC-60 ABS, EC-60 ATC Introduction Manual

Bendix® EC-60™ ABS / ATC Controllers (Standard & Premium Models)

Frame and Cab Mount

SD-13-4863

Standard Frame

Premium Frame

INTRODUCTION

Bendix® EC-60™ controllers are members of a family of electronic
Antilock Braking System (ABS) devices designed to help improve
the braking characteristics of air braked vehicles - including heavy
and medium duty buses, trucks, and tractors. ABS controllers are
also known as Electronic Control Units (ECUs).

Bendix ABS uses wheel speed sensors, ABS modulator valves,
and an ECU to control either four or six wheels of a vehicle. By
monitoring individual wheel turning motion during braking, and
adjusting or pulsing the brake pressure at each wheel, the EC-60
controller is able to optimize slip between the tire and the road
surface. When excessive wheel slip, or wheel lock-up, is detected,
the EC-60™ controller will activate the Pressure Modulator V alves to
simulate a driver pumping the brakes. However, the EC-60™ controller
is able to pump the brakes on individual wheels (or pairs of wheels),
independently , and with greater speed and accuracy than a driver.

In addition to the ABS function, premium models of the EC-60
controller provide an Automatic Traction Control (ATC) feature.
Bendix ATC can improve vehicle traction during acceleration, and
lateral stability while driving through curves. ATC utilizes Engine
Torque Limiting (ETL) where the ECU communicates with the
engine’s controller and/or Differential Braking (DB) where individual
wheel brake applications are used to improve vehicle traction.

Premium EC-60™ controllers have a drag torque control feature
which reduces driven-axle wheel slip (due to driveline inertia) by
communicating with the engine’s controller and increasing the engine
torque.

Standard Cab

Premium Cab

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FIGURE 1 - EC-60™ CONTROLLERS

TABLE OF CONTENTS P A GE
General System Information

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2

ECU Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2

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EC-60

EC-60™ Controllers with PLC . . . . . . . . . . . . . . . . .3

EC-60

ABS Off-Road Switch and Indicator Lamp . . . . . . . 4

EC-60

Power-Up Sequence . . . . . . . . . . . . . . . . . . . . . . . .5

ABS Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

ATC Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Dynamometer Test Mode . . . . . . . . . . . . . . . . . . . .8

Automatic Tire Size Calibration . . . . . . . . . . . . . . .8

ABS Partial Shutdown . . . . . . . . . . . . . . . . . . . . . . .9

System Reconfiguration

EC-60™ Controller System Reconfiguration . . . .10

Troubleshooting

General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Diagnostic Trouble Codes . . . . . . . . . . . . . . . . . .12

Using Hand-Held or PC-based Diagnostics . . . 13
Diagnostic Trouble Code Troubleshooting Index . 1 6

Trouble Code Tests . . . . . . . . . . . . . 18 - 27

Connector and Harnesses . . . . . . . . . . . . . . . 28-31

Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32-34

Wiring Schematics . . . . . . . . . . . . . . . . . . . . . 28-31

Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41

Controller Hardware Configurations . . . .2

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Controller Inputs . . . . . . . . . . . . . . . . . . . .3

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Controller Outputs . . . . . . . . . . . . . . . . . . .4

1

90° Speed

Sensors

Sensor

Clamping

Sleeve

Straight Speed

Sensors

FIGURE 2 - BENDIX® WS-24™ WHEEL SPEED SENSORS

Delivery

(Port 2)

Supply

(Port 1)

Electrical

M-32QR

Modulator

FIGURE 3 - M-32™ AND M-32QR™ MODULATORS

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Connector

Exhaust (Port 3)

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M-32

Modulator

COMPONENTS

The EC-60™ controller’s ABS function utilizes the following
components:

• Bendix® WS-24™ wheel speed sensors (4 or 6,
depending on ECU model and configuration). Each
sensor is installed with a Bendix Sensor Clamping
Sleeve

• Bendix® M-32™ or M-32QR™ Pressure Modulator
V alves (4, 5, or 6 depending on ECU model and
configuration)

• Dash-mounted tractor ABS Indicator Lamp

• Service brake relay valve

• Dash-mounted trailer ABS Indicator Lamp (used on all
towing vehicles manufactured after March 1, 2001)

• Optional blink code activation switch

• Optional ABS of f-road switch. (Off-road feature is not
available on all models - See Chart 1.)

The EC-60™ controller ATC function utilizes the following
additional components:

• Traction control valve (may be integral to the service
brake relay valve or a stand-alone device)

• Dash-mounted A TC status/indicator lamp

• J1939 serial communication to engine control module

• Stop lamp switch input (may be provided using the
ECU hardware input or J1939)

• Optional A TC off-road switch

2

FIGURE 4 - POWER LINE WITHOUT PLC SIGNAL

FIGURE 5 - POWER LINE WITH PLC SIGNAL

ECU MOUNTING

Cab ECUs

Cab-mounted EC-60™ controllers are not protected against
moisture, and must be mounted in an environmentally
protected area.

All wire harness connectors must be properly seated. The
use of secondary locks is strongly recommended.

CAUTION: All unused ECU connectors must be covered
and receive any necessary protection from moisture, etc.

Cab ECUs utilize connectors from the AMP MCP 2.8 product
family.

Frame ECUs

Frame-mounted EC-60™ controllers may be mounted on
the vehicle frame, but only in locations where they will not
be subjected to direct tire spray . ECU mounting bolts must
be torqued to 7.5 to 9 Nm.

CAUTION: The frame wire harness connectors must be
properly seated with the seals intact (undamaged). All
unused connector terminals must be plugged with the
appropriate sealing plugs. Failure to properly seat or seal
the connectors could result in moisture or corrosion damage
to the connector terminals. ECUs damaged by moisture
and/or corrosion are not covered under the Bendix warranty .

Frame ECUs utilize Deutsch connectors.

EC U Mounting Input Sensors PMVs ATC Blink PLC ABS ATC Retarder
Model Voltage Codes J1587 J1939 Off-Road Off-Road Relay

Standard Cab 12 4 4

Frame
Standard Cab 12 4 4
PLC Frame
Premium Cab 12 4/6 4/5/6

Frame
Premium Cab 24 4/6 4/5/6

Serial Communication

CHART 1 - EC-60™ CONTROLLERS AVAILABLE

HARDWARE CONFIGURATIONS

Standard Models

Standard model EC-60™ controllers support four sensor/
four modulator (4S/4M) applications. Certain models
support Power Line Carrier (PLC) communications, with all
models supporting 12 volt installations. See Chart 1 for

more details.

Premium Models

Premium model EC-60™ controllers support applications
up to six sensor/six modulator (6S/6M) installations with
ATC and drag torque control. All 12 volt models support
PLC. 24 volt models do not support PLC. See Chart 1 for

more details.

EC-60™ CONTROLLERS WITH PLC

Since March 1, 2001, all towing vehicles must have an in-cab
trailer ABS Indicator Lamp. Trailers transmit the status of
the trailer ABS over the power line (the blue wire of the J560
connector) to the tractor using a Power Line Carrier (PLC)
signal. See Figures 4 and 5. Typically the signal is
broadcast by the trailer ABS ECU. The application of PLC
technology for the heavy vehicle industry is known as
“PLC4Trucks.” The Standard PLC EC-60™ controller and
the Premium EC-60™ controller (12 volt versions) support
PLC communications in accordance with SAE J2497.

Identifying an EC-60™ Controller with PLC

Refer to the information panel on the ECU label to see if the
controller provides PLC.

An oscilloscope can be used to measure or identify the
presence of a PLC signal on the power line. The PLC signal
is an amplitude and frequency modulated signal. Depending
on the filtering and load on the power line, the PLC signal
amplitude can range from 5.0mVp-p to 7.0 Vp-p. Suggested
oscilloscope settings are AC coupling, 1 volt/div , 100 µsec/
div. The signal should be measured at the ignition power
input of the EC-60™ controller.

Note: An ABS trailer equipped with PLC, or a PLC diagnostic
tool, must be connected to the vehicle in order to generate
a PLC signal on the power line.

Alternatively , the part number shown on the ECU label can
be identified as a PLC or non-PLC model by calling the
Bendix T echTeam at 1-800-AIR-BRAKE (1-800-247-2725).

EC-60™ CONTROLLER INPUTS

Battery and Ignition Inputs

The ECU operates at a nominal supply voltage of 12 or 24
volts, depending on the model of the ECU. The battery
input is connected through a 30 amp fuse directly to the
battery.

The ignition input is applied by the ignition switch through a
5 amp fuse.

Ground Input

The EC-60™ controller supports one ground input. See pages
35 to 40 for system schematics.

ABS Indicator Lamp Ground Input (Cab ECUs
Only)

EC-60™ cab ECUs require a second ground input (X1-12)
for the ABS indicator lamp. The X1 wire harness connector
contains an ABS indicator lamp interlock (X1-15), which
shorts the ABS indicator lamp circuit (X1-18) to ground if
the connector is removed from the ECU.

Bendix® WS-24™ Wheel Speed Sensors

Wheel speed data is provided to the EC-60™ controller from
the WS-24™ wheel speed sensor (see Figure 2). Vehicles
have an exciter ring (or “tone ring”) as part of the wheel
assembly, and as the wheel turns, the teeth of the exciter
ring pass the wheel speed sensor, generating an AC signal.
The EC-60™ controller receives the AC signal, which varies
in voltage and frequency as the wheel speed changes.

Vehicle axle configurations and A TC features determine the
number of WS-24™ wheel speed sensors that must be used.
A vehicle with a single rear axle requires four wheel speed
sensors. Vehicles with two rear axles can utilize six wheel
speed sensors for optimal ABS and A TC performance.

3

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.

ABS Off-Road Switch and Indicator Lamp
Operation

WARNING: The ABS off-road mode should not be used on

normal, paved road surfaces because vehicle stability and
steerability may be affected. When the ECU is placed in
the ABS off-road mode, the ABS Indicator Lamp will flash
constantly to notify the vehicle operator that the off-road
mode is active.

Premium EC-60™ controllers use a dash-mounted switch
to place the ECU into the ABS off-road mode. 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 EC-60™ controller.

(If you need to know if your EC-60™ controller uses a J1939
message to operate the lamp, e-mail [e-mail],
specifying the ECU part number, or call 1-800-AIR-BRAKE
and speak to the Bendix TechT eam.)

Stop Lamp Switch (SLS)

The Premium 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
know the driver’s intention. This can be provided to the ECU
via J1939 communications, or hardware input.

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 EC-60™ controller to modify driver
applied air pressure to the service brakes during ABS or
ATC activation (See pages 6-8). 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 precisely modify
the brake pressure during an antilock braking event. The
hold solenoid is normally open and the release solenoid is
normally closed.

Traction Control Valve (TCV)

Premium EC-60™ controllers will activate the TCV during
differential braking A TC event s. The TCV may be a separate
valve or integrated into the rear axle relay valve.

ABS Indicator Lamp Control with Optional
Diagnostic Blink Code Switch (Cab and Frame
ECUs)

Cab and frame-mount EC-60™ controllers have internal
circuitry to control the ABS Indicator Lamp on the dash
panel.

The ABS Lamp Illuminates:

1. During power up (e.g. when the vehicle is started) and
turns off after the self test is completed, providing no
Diagnostic Trouble Codes (DTCs) are present on the
tractor.

2. If the ECU is unplugged or has no power.

3. When the ECU is placed into the ABS off-road mode
(the lamp flashes rapidly).

4. T o display blink codes for diagnostic purposes after the
external diagnostic switch is activated.

Certain models of the EC-60™ controller communicate with
other vehicle control modules to operate the ABS Indicator
Lamp using serial communications. (If you need to know if
your EC-60™ controller uses serial communications to
operate the lamp, e-mail [e-mail], specifying the
ECU part number , or call 1-800-AIR-BRAKE and speak to
the Bendix T echTeam.)

Indicator Lamp Control Using Serial
Communications Links

As mentioned above, depending on the vehicle
manufacturer, the dash indicator lamps (ABS, ATC, and
trailer ABS) may be controlled using serial communications
links. In these cases, the EC-60™ controller will send a
serial communications message over the J1939 or J1587
links indicating the required status of the lamp(s). Another
vehicle control module receives the message and controls
the indicator lamp(s).

Retarder Relay Disable Output

The retarder relay disable output may be used to control a
retarder disable relay .

When configured to use this output, the ECU will energize
the retarder disable relay and inhibit the use of the retarder
as needed.

SAE J1939 Serial Communications

A Controller Area Network (CAN) data link (SAE J1939) is
provided for communication. This link is used for various
functions, such as:

• T o disable retarding devices during ABS operation

• T o request torque converter lock-up during ABS operation

• To share information such as wheel speed and ECU

status with other vehicle control modules

Premium EC-60™ controllers utilize the J1939 data link for
A TC and drag torque control functions.

4

ABS System

Status Indicators

Powered Vehicle ABS

Indicator Light

Trailer ABS

Indicator Light

(PLC Detected)*

ON
OFF

ON
OFF

0.5

Power

Application

2.5

2.0

ATC System

Power

Application

Status Indicator

0.5

3.0 (sec.)1.5

Engine torque limiting

and differential braking

enabled

No A TC

ON
OFF

ON
OFF

2.0

2.5

3.0 (sec.)1.5

Trailer ABS

Indicator Light

(PLC Not Detected)

*Some vehicle manufacturers may illuminate the trailer
ABS indicator lamp at power-up regardless of whether a
PLC signal is detected from the trailer or not. Consult the
vehicle manufacturer’s documentation for more details.

FIGURE 6 - ABS DASH LIGHTS START UP SEQUENCE

ON
OFF

Trailer ABS Indicator Lamp Control

Certain models of the EC-60™ controller activate a trailer
ABS Indicator Lamp (located on the dash panel) that
indicates the status of the trailer ABS unit on one, or more
trailers, or dollies. T ypically , the EC-60™ controller directly
controls the trailer ABS Indicator Lamp based on the
information it receives from the trailer ABS.

Alternatively , some vehicles require the EC-60™ controller
to activate the trailer ABS Indicator Lamp by communicating
with other vehicle controllers using serial communications.
(If you need to know if your EC-60™ controller uses a serial
communications message to operate the lamp, e-mail
[e-mail], specifying the ECU part number, or call
1-800-AIR-BRAKE and speak to the Bendix T echTeam.)

SAE J1708/J1587 Serial Communications

An SAE J1708 data link, implemented according to SAE
J1587 recommended practice, is available for diagnostic
purposes, as well as ECU status messages.

ATC Lamp Output/ATC Off-Road Switch Input

Premium ECUs control the ATC dash lamp.
The A TC Lamp Illuminates:

1. During power up (e.g. when the vehicle is started) and
turns off after the self test is completed, providing no
diagnostic trouble codes are present.

2. When A TC is disabled for any reason.

3. During an A TC event (the lamp will flash rapidly).

4. When the ECU is placed in the A TC off-road mode (the
lamp will flash slowly at a rate of 1.0 seconds on, 1.5
seconds off). This notifies the vehicle operator that the
off-road mode is active.

FIGURE 7 - ATC INDICATOR LIGHT START UP SEQUENCE

Interaxle Differential Lock Control (AWD T ransfer Case)

Premium ECUs can control the interaxle differential lock
(AWD transfer case). This is recommended on AWD
vehicles, but the ECU must be specially configured to provide
this feature. E-mail to [e-mail] for more details.

POWER-UP SEQUENCE

WARNING: The vehicle operator should verify proper

operation of all installed indicator lamps (ABS, ATC, and
trailer ABS) when applying ignition power and during vehicle
operation.

Lamps that do not illuminate as required when ignition power
is applied, or remain illuminated after ignition power is
applied, indicate the need for maintenance.

ABS Indicator Lamp Operation

The ECU will illuminate the ABS Indicator Lamp for
approximately three seconds when ignition power is applied,
after which the lamp will extinguish if no diagnostic trouble
codes are detected.

The ECU will illuminate the ABS Indicator Lamp whenever
full ABS operation is not available due to a diagnostic trouble
code. In most cases, partial ABS is still available.

ATC Status/Indicator Lamp Operation

The ECU will illuminate the A TC lamp for approximately 2.5
seconds when ignition power is applied, after which the
lamp will extinguish, if no diagnostic trouble codes are
detected.

The ECU will illuminate the ATC Indicator Lamp whenever
A TC is disabled due to a diagnostic trouble code.

Trailer ABS Indicator Lamp Operation

Certain models of the ECU will control the Trailer ABS
Indicator Lamp when a PLC signal (SAE J2497) from a trailer
ABS ECU is detected.

5

Right Steer

Driver

Left Steer

Right Drive

Left Drive

Additional

Left

Additional

Right

FIGURE 8 - VEHICLE ORIENTATION (TYPICAL)

ECU Configuration Test

Within two seconds of the application of ignition power, the
ECU will perform a test to detect system configuration with
regards to the number of wheel speed sensors and PMVs.
This can be audibly detected by a rapid cycling of the PMVs.
(Note: The ECU will not perform the configuration test when
wheel speed sensors show that the vehicle is in motion.)

Pressure Modulator Valve Chuff Test

After the performance of the configuration test, the EC-60
controller will perform a Bendix-patented PMV Chuff Test.
The Chuff Test is an electrical and pneumatic PMV test
that can assist maintenance personnel in verifying proper
PMV wiring and installation.

With brake pressure applied, a properly installed PMV will
perform one sharp audible exhaust of air by activating the
hold solenoid twice and the release solenoid once. If the
PMV is wired incorrectly , it will produce two exhausts of air
or none at all.

The EC-60™ controller will perform a PMV chuff test on all
installed modulators in the following order:

• Steer Axle Right PMV

• Steer Axle Left PMV

• Drive Axle Right PMV

• Drive Axle Left PMV

• Additional Axle Right PMV

• Additional Axle Left PMV
The pattern will then repeat itself.
The ECU will not perform the PMV Chuff Test when wheel

speed sensors show that the vehicle is in motion.

ABS OPERATION

Bendix ABS uses wheel speed sensors, ABS modulator
valves, and an ECU to control either four or six wheels of a
vehicle. By monitoring individual wheel turning motion during
braking, and adjusting or pulsing the brake pressure at each
wheel, the EC-60
the tire and the road surface. When excessive wheel slip,
or wheel lock-up, is detected, the EC-60
activate the Pressure Modulator V alves to simulate a driver
pumping the brakes. However, the EC-60™ controller is
able to pump the brakes on individual wheels (or pairs of
wheels), independently, and with greater speed and
accuracy than a driver.

Steer Axle Control

Although both wheels of the steer axle have their own wheel
speed sensor and pressure modulator valve, the EC-60
controller blends the applied braking force between the two
steering axle brakes. This Bendix patented brake application
control, called Modified Individual Regulation (MIR), is
designed to help reduce steering wheel pull during an ABS
event on road surfaces with poor traction (or areas of poor

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traction, e.g. asphalt road surfaces with patches of ice).

Single Drive Axle Control (4x2 Vehicle)

For vehicles with a single rear drive axle (4x2), the brakes
are operated independently by the EC-60™ controller, based
on the individual wheel behavior.

Dual Drive Axle Control (4S/4M Configuration)

For vehicles with dual drive axles (6x4) using a 4S/4M
configuration, one ABS modulator controls both right-side
rear wheels and the other modulator controls both left-side
rear wheels. Both wheels on each side receive equal brake
pressure during an ABS stop. The rear wheel speed sensors
must be installed on the axle with the lightest load.

Dual Rear Axle Control (6S/6M Configuration)

For vehicles with dual rear axles (6x4, 6x2) using a 6S/6M
configuration, the rear wheels are controlled independently .
Therefore, brake application pressure at each wheel is
adjusted according to the individual wheel behavior on the
road surface.

6x2 Vehicles with 6S/5M Configuration

6x2 vehicles can utilize a 6S/5M configuration, with the
additional axle (a non-driven rear axle) having two sensors,
but only one Pressure Modulator Valve. In this case, the
PMV controls both wheels on the additional axle. The
additional axle wheels would receive equal brake pressure,
based on the wheel that is currently experiencing the most
wheel slip.

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controller is able to optimize slip between

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controller will

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6

Normal Braking

During normal braking, brake pressure is delivered through
the ABS PMV and into the brake chamber. If the ECU
does not detect excessive wheel slip, it will not activate
ABS control, and the vehicle stops with normal braking.

Retarder Brake System Control

On surfaces with low traction, application of the retarder
can lead to high levels of wheel slip at the drive axle wheels,
which can adversely affect vehicle stability .

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T o avoid this, the EC-60
as soon as a lock-up is detected at one (or more) of the
drive axle wheels.

When the ECU is placed in the ABS off-road mode, it will
switch off the retarder only when ABS is active on a steer
axle wheel and a drive axle wheel.

controller switches off the retarder

Optional ABS Off-Road Mode

On some road conditions, particularly when the driving
surface is soft, the stopping distance with ABS may be
longer than without ABS. This can occur when a locked
wheel on soft ground plows up the road surface in front of
the tire, changing the rolling friction value. Although vehicle
stopping distance with a locked wheel may be shorter than
corresponding stopping distance with ABS control, vehicle
steerability and stability is reduced.

Premium EC-60™ controllers have an optional control mode
that more effectively accommodates these soft road
conditions to shorten stopping distance while maintaining
optimal vehicle steerability and stability .

WARNING: The ABS off-road mode should not be used on
normal, paved road surfaces because vehicle stability and
steerability may be reduced. The flashing ABS Indicator
Lamp communicates the status of this mode to the driver.

The vehicle manufacturer should provide the optional ABS
off-road function only for vehicles that operate on unpaved
surfaces or that are used in off-road applications, and is
responsible for insuring that vehicles equipped with the ABS
off-road function meet all FMVSS-121 requirements and have
adequate operator indicators and instructions.

The vehicle operator activates the off-road function with a
switch on the dash panel. A flashing ABS Indicator Lamp
indicates to the driver that the ABS off-road function is
engaged. To exit the ABS off-road mode, depress and
release the switch.

All-Wheel Drive (AWD) Vehicles

AWD vehicles with an engaged interaxle differential (steer
axle to rear axle)/AWD transfer case may have negative
effects on ABS performance. Optimum ABS performance
is achieved when the lockable differentials are disengaged,
allowing individual wheel control.

Premium EC-60™ controllers can be programmed
specifically for this configuration to control the differential

lock/unlock solenoid in the AWD transfer case. When
programmed to do so, the ECU will disengage the locked
interaxle/AWD transfer case during an ABS event and
reengage it once the ABS event has ended.

ATC OPERATION

ATC Functional Overview

Just as ABS improves vehicle stability during braking, A T C
improves vehicle stability and traction during vehicle
acceleration. The EC-60™ controller A TC function uses the
same wheel speed information and modulator control as
the ABS function. The EC-60™ controller detects excessive
drive wheel speed, compares the speed of the front, non­driven wheels, and reacts to help bring the wheel spin under
control. The EC-60™ controller can be configured to use
engine torque limiting and/or differential braking to control
wheel spin. For optimal ATC performance, both methods
are recommended.

ATC Lamp Operation

The A TC Lamp Illuminates:

1. During power up (e.g. when the vehicle is started) and
turns off after the self test is completed, providing no
diagnostic trouble codes are present.

2. When A TC is disabled for any reason.

3. During an A TC event (the lamp will flash rapidly). When
A TC is no longer active, the ATC active/indicator lamp
turns off.

4. When the ECU is placed in the A TC off-road mode (the
lamp will flash at a rate of 1.0 seconds on, 1.5 seconds
off). This notifies the vehicle operator that the off-road
mode is active.

Differential Braking

Differential braking is automatically activated when drive
wheel(s) on one side of the vehicle are spinning, which
typically occur on asphalt road surfaces with patches of
ice. The traction system will then lightly apply the brake to
the drive wheel(s) that are spinning. The vehicle differential
will then drive the wheels on the other side of the vehicle.

Differential braking is available at vehicle speeds up to 25
MPH.

Disabling ATC Differential Braking

ATC differential braking is disabled under the following
conditions:

1. During power up (e.g. when the vehicle is started), until
the ECU detects a service brake application.

2. If the ECU receives a J1939 message indicating that
the vehicle is parked.

3. When the dynamometer test mode is active. The
dynamometer test mode is entered using the diagnostic
blink code switch or by using a diagnostic tool (such
as Bendix® ACom™ Diagnostics).

7

4. In response to a serial communications request from a
diagnostic tool.

5. During brake torque limiting to avoid overheating of the
brakes.

6. When certain diagnostic trouble code conditions are
detected.

Engine Torque Limiting (ETL) with Smart ATC

™

Traction Control

The EC-60™ controller uses Engine T orque Limiting to control
drive axle wheel slip. This is communicated to the engine
control module (using J1939), and is available at all vehicle
speeds.

Bendix® Smart ATC™ Traction Control

The EC-60™ controller has an additional feature known as

Smart A TC

monitors the accelerator pedal position (using J1939) to
help provide optimum traction and vehicle stability. By
knowing the driver’s intention and adapting the target slip of
the drive wheels to the driving situation, the Smart ATC
traction control allows higher wheel slip when the accelerator
pedal is applied above a preset level.

The target wheel slip is decreased when driving through a
curve for improved stability .

Disabling A TC Engine Control and Smart A TC™ Traction
Control

ATC Engine Control and Smart ATC™ traction control will
be disabled under the following conditions:

1. In response to a serial communications request from
an off-board tool.

2. At power-up until the ECU detects a service brake
application.

3. If the ECU receives a J1939 message indicating that
the vehicle is parked.

4. If the dynamometer test mode is active. This may be
accomplished via an off-board tool or the diagnostic blink
code switch.

5. When certain diagnostic trouble code conditions are
detected.

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traction control. Smart A T C™ traction control

Optional ATC Off-Road Mode

In some road conditions, the vehicle operator may desire
additional drive wheel slip when A TC is active. The Premium
EC-60™ controller has an optional control mode to permit
this desired performance.

The vehicle operator can activate the off-road function with
a switch on the dash panel. Alternately, a J1939 message
may be used to place the vehicle in this mode. The ATC
Indicator Lamp will flash continually to confirm that the off­road A TC function is engaged.

To exit the ATC off-road mode, depress and release the
A TC off-road switch.

Drag Torque Control Functional Overview

Premium EC-60™ controllers have a feature referred to as
drag torque control which reduces wheel slip on a driven
axle due to driveline inertia. This condition is addressed by
increasing the engine torque to overcome the inertia.

Drag torque control increases vehicle stability on low-traction
road surfaces during down-shifting or retarder braking.

Dynamometer Test Mode

WARNING: A TC must be disabled prior to conducting any

dynamometer testing. When the Dynamometer T est Mode
is enabled, A TC brake control and engine control along with
drag torque control are turned off. This test mode is used
to avoid torque reduction or torque increase and brake control
activation when the vehicle is operated on a dynamometer
for testing purpose.

The Dynamometer T est Mode may be activated by pressing
and releasing the diagnostic blink code switch five times or
by using a hand-held or PC-based diagnostic tool.

™

The Dynamometer T est Mode will remain active even if power
to the ECU is removed and re-applied. Press and release
the blink code switch three times, or use a hand-held or
PC-based diagnostic tool to exit the test mode.

Automatic Tire Size Calibration

The ECU requires a precise rolling circumference ratio
between steer axle and drive axle tires in order for ABS and
ATC to perform in an optimal manner. For this reason, a
learning process continuously takes place in which the
precise ratio is calculated. This calculated value is stored
in the ECU memory provided the following conditions are
met:

1. Rolling-circumference ratio is within the permissible
range.

2. Vehicle speed is greater than approximately 12 MPH.

3. No acceleration or deceleration is taking place.

4. There are no active speed sensor diagnostic trouble
codes.

The ECU is provided with a ratio value of 1.00 as a default
setting. If the automatic tire size alignment calculates a
different value, this is used to overwrite the original figure in
the memory . This process adapts the ABS and A TC function
to the vehicle.

Acceptable Tire Sizes

The speed calculation for an exciter ring with 100 teeth is
based on a default tire size of 510 revolutions per mile.
This figure is based on the actual rolling circumference of
the tires, which varies with tire size, tire wear, tire pressure,
vehicle loading, etc.

The ABS response sensitivity is reduced when the actual
rolling circumference is excessive on all wheels. For a 100
tooth exciter ring, the minimum number of tire revolutions

8

per mile is 426, and the maximum is 567. The ECU will set
diagnostic trouble codes if the number or revolutions are
out of this range.

In addition, the size of the steer axle tires compared to the
drive axle tires also has to be within the ABS system design.
T o avoid diagnostic trouble codes, the ratio of the ef fective
rolling circumference of the steer axle, divided by the effective
rolling circumference of the drive axle, must be between

0.85 to 1.15.

ABS PARTIAL SHUTDOWN

Depending which component the trouble code is detected
on, the ABS and ATC functions may be fully or partially
disabled. Even with the ABS indicator lamp on, the EC-

™

controller may still provide ABS function on wheels

60
that are not affected. The EC-60
serviced as soon as possible.

Steer Axle ABS Modulator Diagnostic Trouble
Code

ABS on the affected wheel is disabled. ABS and A TC on all
other wheels remains active.

Drive Axle/Additional Axle ABS Modulator
Diagnostic Trouble Code

ATC is disabled. ABS on the affected wheel is disabled.
ABS on all other wheels remains active.

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controller should be

Drive Axle/Additional Axle Wheel Speed Sensor
Diagnostic Trouble Code

ATC is disabled. In a four sensor system, ABS on the
affected wheel is disabled, but ABS on all other wheels
remains active.

In a six sensor system, ABS remains active by using input
from the remaining rear wheel speed sensor on the same
side.

ATC Modulator Diagnostic Trouble Code

A TC is disabled. ABS remains active.

J1939 Communication Diagnostic Trouble Code

A TC is disabled. ABS remains active.

ECU Diagnostic Trouble Code

ABS and ATC are disabled. The system reverts to normal
braking.

Voltage Diagnostic Trouble Code

While voltage is out of range, ABS and ATC are disabled.
The system reverts to normal braking. When the correct
voltage level is restored, full ABS and ATC function is
available. Operating voltage range is 9.0 to 17.0 VDC.

Steer Axle Wheel Speed Sensor Diagnostic
Trouble Code

The wheel with the diagnostic trouble code is still controlled
by using input from the remaining wheel speed sensor on
the front axle. ABS remains active on the rear wheels.
A TC is disabled.

9

Reconfiguring EC-60™ Controllers

SYSTEM CONFIGURATION

The EC-60™ controller is designed to allow the technician
to change the default system settings (chosen by the vehicle
OEM) to provide additional or customized features. When
replacing an ECU, be sure to use an equivalent Bendix
replacement part number so that the standard default set­tings are provided.

Depending on the model, the customizable features include
ABS control settings, engine module communication etc.
Many of these settings can be reconfigured using a hand­held or PC-based software, such as the Bendix® ACom
Diagnostics program.

ECU RECONFIGURATION

Reconfiguring Standard ECUs

Reconfigurating an EC-60™ controller may be carried out
by using the Blink Code Switch or by using a hand-held or
PC-based diagnostic tool.

Note: During the reconfiguration process, and independently
from any reconfiguration being carried out by the technician,
standard ECUs automatically check the J1939 serial link
and communicate with other vehicle modules. In particular,
if the serial link shows that the vehicle has a retarder device
present, the ECU will configure itself to communicate with
the retarder device for improved ABS performance. For
example, if the ECU detects the presence of a retarder
disable relay during a reconfiguration, it will configure itself
to control the relay to disable the retarding device as needed.

Reconfiguring Premium ECUs

As with standard ECUs, the Premium EC-60™ controller
also carries out, independently from any reconfiguration
being carried out by the technician, an automatic check of
the J1939 serial link and communicate with other vehicle
modules. This includes checking for ATC and retarder
disable relay operation. In addition, premium EC-60
controllers will determine the number of wheel speed
sensors and PMVs installed and configure itself accordingly .

6S/5M Configuration

™

Premium EC-60™ controllers will configure for 6S/5M
operation when a reconfiguration event is initiated and the
ECU detects that an additional axle PMV is wired as follows:

PMV Connector ECU Connector

Hold Right Additional Axle Hold
Release Left Additional Axle Release
Common Right Additional Axle Common

See 6S/5M System Schematics (pages 37 & 40) for details.

Reconfiguration Using the Blink Code Switch

The reconfiguration event is the same for both Standard
and Premium ECUs. With ignition power removed from the
EC-60™ controller, depress the blink code switch. After the
ignition power is activated, depress and release the switch
seven times to initiate a reconfiguration event.

Diagnostic T ool

A reconfiguration event may be initiated using a hand-held
or PC-based diagnostic tool to communicate with the ECU
over the SAE J1587 diagnostic link.

™

10

Troubleshooting: General

SAFE MAINTENANCE PRACTICES

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

When working on or around a vehicle, the following
general precautions should be observed at all times:

1. Park the vehicle on a level surface, apply the
parking brakes, and always block the wheels.
Always wear safety glasses.

2. Stop the engine and remove ignition key when
working under or around the vehicle. When
working in the engine compartment, the engine
should be shut off and the ignition key should be
removed. Where circumstances require that the
engine be in operation, EXTREME CAUTION should
be used to prevent personal injury resulting from
contact with moving, rotating, leaking, heated or
electrically charged components.

3. Do not attempt to install, remove, disassemble or
assemble a component until you have read and
thoroughly understand the recommended
procedures. Use only the proper tools and observe
all precautions pertaining to use of those tools.

4. If the work is being performed on the vehicle’s air
brake system, or any auxiliary pressurized air
systems, make certain to drain the air pressure from
all reservoirs before beginning ANY work on the
vehicle. If the vehicle is equipped with an AD-IS
air dryer system or a dryer reservoir module, be
sure to drain the purge reservoir.

5. Following the vehicle manufacturer’s
recommended procedures, deactivate the electrical
system in a manner that safely removes all
electrical power from the vehicle.

6. Never exceed manufacturer’s recommended
pressures.

7. Never connect or disconnect a hose or line
containing pressure; it may whip. Never remove a
component or plug unless you are certain all
system pressure has been depleted.

8. Use only genuine Bendix® replacement parts,
components and kits. Replacement hardware,
tubing, hose, fittings, etc. must be of equivalent
size, type and strength as original equipment and
be designed specifically for such applications and
systems.

9. Components with stripped threads or damaged
parts should be replaced rather than repaired. Do
not attempt repairs requiring machining or welding
unless specifically stated and approved by the
vehicle and component manufacturer.

10. Prior to returning the vehicle to service, make
certain all components and systems are restored
to their proper operating condition.

11. For vehicles with Antilock Traction Control (ATC),
the ATC function must be disabled (ATC indicator
lamp should be ON) prior to performing any vehicle
maintenance where one or more wheels on a
drive axle are lifted off the ground and moving.

REMOVING THE EC-60™ CONTROLLER
ASSEMBLY

1. Turn vehicle ignition off.

2. Remove as much contamination as possible prior to

disconnecting air lines and electrical connections.

3. Note the EC-60™ controller assembly mounting position

on the vehicle.

4. Disconnect the electrical connectors from the EC-60

controller.

5. Remove and retain the mounting bolts that secure the

EC-60™ controller.

INSTALLING A NEW EC-60™ CONTROLLER

CAUTION! When replacing the EC-60™ controller, verify

that the unit you are installing has the correct default
settings. Failure to do so could result in a loss of features,
such as ATC and PLC, or noncompliance with U.S.
regulations such as FMVSS 121. It is recommended to
use only the correct replacement part number. However,

®

most configuration settings can be altered using the Bendix
ACom™ ABS Diagnostic Software program.

Verify correct operation of the EC-60™ controller system
and indicator lamps prior to putting the vehicle back into
service. T owing vehicles manufactured af ter March 1, 2001
must support the trailer ABS indicator lamp located on the
dash.

For further information, contact either the vehicle
manufacturer, Bendix or your local authorized Bendix dealer .

1. Position and secure the EC-60™ controller in the original

mounting orientation using the mounting bolts retained
during removal. On frame-mount ECUs, torque the
mounting bolts to 7.5 to 9 NM (66-80 in. Ibs). For cab­mount units use no more torque than is necessary to
firmly secure the ECU into position. Over-tightening
the mounting hardware can cause damage to the EC-60
controller.

2. Reconnect the electrical connectors to the EC-60

controller.

3. Apply power and monitor the EC-60™ controller power-

up sequence to verify proper system operation.

See Troubleshooting: Wiring section beginning on page 32
for more information on wire harnesses.

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™

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11

Troubleshooting: Blink Codes and Diagnostic Modes

ECU DIAGNOSTICS

The EC-60™ controller contains self-testing diagnostic
circuitry that continuously checks for the normal operation
of internal components and circuitry, as well as external
ABS components and wiring.

Active Diagnostic Trouble Codes

When an erroneous system condition is detected, the
EC-60™ controller:

1. Illuminates the appropriate indicator lamp(s) and
disengages part or all of the ABS and ATC functions.
(See page 9.)

2. Places the appropriate trouble code information in the
ECU memory.

3. Communicates the appropriate trouble code information
over the serial communications diagnostic link as
required. Hand-held or PC-based diagnostic tools attach
to the vehicle diagnostic connector, typically located
on or under the dash (see Figure 9).

Located on
Dash Panel

FIGURE 9 - TYPICAL VEHICLE DIAGNOSTIC CONNECTOR
LOCATIONS (J1708/J1587, J1939)

Or

Located Under

Dash Panel

BLINK CODES

Blink codes allow a technician to troubleshoot ABS problems
without using a hand-held or PC-based diagnostic tool.
Instead, information about the ABS system is communicated
by the ECU using the ABS indicator lamp to display
sequences of blinks.

Note: The ECU will not enter the diagnostic blink code
mode if the wheel speed sensors show that the vehicle is in
motion. If the ECU is in the diagnostic blink code mode
and then detects vehicle motion, it will exit the blink code
mode.

In addition, by operating the blink code switch as described
below, one of several diagnostic modes can be entered.
See Diagnostic Modes below.

Blink Code Switch Activation

When activating the blink code switch:

1. Wait at least two seconds after “ignition on.” (Except
when entering Reconfiguration Mode - see
Reconfiguration section on page 10)

2. For the ECU to recognize that the switch is activated
“on,” the technician must press for at least 0.1 seconds,
but less than 5 seconds. (If the switch is held for more
than 5 seconds, the ECU will register a malfunctioning
switch.)

3. Pauses between pressing the switch when a sequence
is required, (e.g. when changing mode) must not be
longer than 2 seconds.

4. After a pause of 3.5 seconds, the ECU will begin
responding with output information blinks. See Figure
10 for an example.

FIGURE 10 - EXAMPLE OF BLINK CODE MESSAGE

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Blink Code Timing

The ECU responds with a sequence of blink codes. The
overall blink code response from the ECU is called a
“message.” Each message includes, depending on the

mode selected by the technician, a sequence of one or
more groups of blinks. Simply record the number of blinks
for each sequence and then use the troubleshooting index
on page 17 for active or inactive trouble codes and you will
be directed to the page that provides troubleshooting
information.

NOTE:

1. Sequences of blinks illuminate the ABS indicator lamp
for half a second, with half-second pauses between them.

2. Pauses between blink code digits are 1.5 seconds.

3. Pauses between blink code messages are 2.5 seconds.

4. The lamp remains on for 5 seconds at the end of
messages.

Once the ABS indicator lamp begins displaying a sequence
of codes, it continues until all blink code messages have
been displayed and then returns to the normal operating
mode. During this time, the ECU will ignore any additional
blink code switch activation.

All trouble codes, with the exception of voltage and J1939
trouble codes, will remain in an active state for the remainder
of the power cycle.

Voltage trouble codes will clear automatically when the
voltage returns within the required limits. All ABS functions
will be re-engaged.

J1939 trouble codes will clear automatically when
communications are re-established.

DIAGNOSTIC MODES

In order to communicate with the ECU, the controller has
several modes that the technician can select, allowing
information to be retrieved, or other ECU functions to be
accessed.

Diagnostic Modes

T o enter the various diagnostic modes:

No. of Times to
Press the Blink System Mode Entered
Code Switch

1 Active diagnostic trouble code retrieval
2 Inactive diagnostic trouble code retrieval
3 Clear active diagnostic trouble codes
4 System configuration check
5 Dynamometer Test Mode

7* Reconfigure ECU

* To enter the Reconfiguration Mode, the switch must

be held in before the application of ignition power. Once
the power is supplied, the switch is released and then
pressed seven times.

CHART 2 - DIAGNOSTIC MODES

Active Diagnostic Trouble Code Mode

For troubleshooting, typically the Active and Inactive
Diagnostic Trouble Retrieval Modes are used. The technician
presses the blink code switch once and the ABS indicator
lamp flashes a first group of two codes, and if there are
more trouble codes recorded, this is followed by a second
set of codes, etc. (See page 17 for a directory of these
codes.) All active trouble codes may also be retrieved using
a hand-held or PC-based diagnostic tool, such as the
Bendix® ACom™ Diagnostics software.

To clear active diagnostic trouble codes (as problems are
fixed), simply clear (or “self-heal”) by removing and
re-applying ignition power. The only exception is for wheel
speed sensor trouble codes, which clear when power is
removed, re-applied, and the ECU detects valid wheel speed
from all wheel speed sensors. Alternately, codes may be
cleared by pressing the diagnostic blink code switch 3 times
(to enter the Clear Active Diagnostic Trouble Code Mode)
or by using a hand-held or PC-based diagnostic tool. Hand­held or PC-based diagnostic tools are able to clear wheel
speed sensor trouble codes without the vehicle being driven.

Inactive Diagnostic Trouble Code Mode

The ECU stores past trouble codes and comments (such
as configuration changes) in its memory. This record is
commonly referred to as “event history.” When an active
trouble code is cleared, the ECU stores it in the event history
memory as an inactive trouble code.

13

Using blink codes, the technician may review all inactive
trouble codes stored on the ECU.

The ABS indicator lamp

will display inactive diagnostic blink codes when the
diagnostic blink code switch is depressed and released
two times. See page 17 for the index showing trouble codes
and the troubleshooting guide page to read for help.

Inactive trouble codes, and event history, may be retrieved
and cleared by using a hand-held or PC-based diagnostic
tool, such as the Bendix® ACom™ Diagnostics software.

Clearing Active Diagnostic Trouble Codes

The ECU will clear active trouble codes when the diagnostic
blink code switch is depressed and released three times.

System Configuration Check Mode

The ABS indicator lamp will display system configuration
information when the diagnostic blink code switch is
depressed and released four times. The lamp will blink out
configuration information codes using the following patterns.
(See Chart 3). In this mode the ECU tells the technician,
by means of a series of six blink codes, the type of ABS
system that the ECU has been set up to expect. For
example, if the fourth blink code is a three, the technician
knows that a 6S/5M sensor/modulator configuration has
been set.

Dynamometer Test Mode

The Dynamometer T est Mode is used to disable A TC when
needed (e.g. when performing any vehicle maintenance
where the wheels are lifted off the ground and moving,
including dyno testing). This mode is not reset by power
off, power on, cycling. Instead a hand-held or PC-based
diagnostic tool must be used to change the setting.
Alternatively , depressing and releasing the blink code switch
three times will cause the ECU to exit the blink code mode.

1st Number System Power
1 12 Volts
2 24 Volts
2nd Number Wheel Speed Sensors
4 4 Sensors
6 6 Sensors
3rd Number Pressure Modulator Valves
4 4 Modulators
5 5 Modulators
6 6 Modulators
4th Number ABS Configuration
1 4S/4M or 6S/6M
2 6S/4M
3 6S/5M
5th Number Traction Control Configuration
2 No A TC
3 ATC Engine Control Only
4 ATC Brake Control Only
5 Full ATC (Engine Control & Brake Control)
6th Number Retarder Configuration
1 No Retarder
2 J1939 Retarder
3 Retarder Relay

4 J1939 Retarder, Retarder Relay

CHART 3 - SYSTEM CONFIGURATION CHECK

Reconfigure ECU Mode

Vehicle reconfiguration is carried out by using the
Reconfigure ECU Mode. (See page 10.) Note: T o enter the
Reconfiguration Mode, the blink code switch must be held
in before the application of ignition power. Once the power
is supplied, the switch is released and then pressed seven
times.

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