SD-13-47671

®

Bendix® TABS‑6™ Advanced Single-Channel Trailer ABS Module
ECU Cover
(Sealed)

Through-holes for Frame
(Chassis) Mounting

ECU Connector
Cover
(Removable)

3/8-in. NPT Load Port
(Air Suspension)
3/4-in. NPT Supply Port
with Integral Filter

ECU Part Number
Label
(See Page 43)

18-Pin Connector

Wheel Speed
Sensor
Connectors

3/8-in. NPT Control Port
with Integral Filter
Integrated
Modulator
Relay Valve

Four (4) 3/8-in. NPT
Delivery Ports
(To Brake Chambers)

To Remove Cover
Slide Lock Tab

FIGURE 1 - TABS‑6 ADVANCED SINGLE-CHANNEL MODULE (TABS‑6 ADV) PLUS VIEW OF CONNECTOR

1. INTRODUCTION
The Bendix TABS‑6 Advanced module is an integrated
single-channel (2S/1M) trailer service brake module controller
for air-braked heavy-duty semi-trailers that features Bendix®
Antilock Brake System (ABS) and Bendix® Trailer Roll Stability
Program (TRSP®).
®

™

Installed on semi-trailers, the module acts as a relay valve
during normal braking, but during ABS events it will intervene
to help maintain vehicle stability and minimize stopping
distance by preventing wheel lock-up. The Bendix TRSP
monitors the trailer’s motion and reduces the risk of roll overs
by automatically applying the brakes when a risk of roll over
is detected.
This module features:
● A modular design with an integrated Electronic Control Unit
(ECU); pressure sensors; a lateral acceleration sensor; and
Modulator Relay Valve (MRV) – eliminating external pigtail
harnesses for these components.
● An operating voltage range of 8 - 32 volts.
● Optional mounting to the service reservoir or to the chassis,
without additional brackets.
● An electronic odometer with trip counters & service interval
options.

SectionTABLE OF CONTENTS . . . . . . . . . . . . PAGE
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
2. General Safety Guidelines . . . . . . . . . . . . . . . . 2-3
3. Antilock Brake System (ABS) Operation . . . . . . 3
4. Trailer Roll Stability Program (TRSP) Operation 4
5. Components . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6
6. Mounting Configurations . . . . . . . . . . . . . . . . . . . 7
7. Pigtail Wiring Harnesses . . . . . . . . . . . . . . . . . . .7
8. ABS Indicator Lamp . . . . . . . . . . . . . . . . . . . . . . 8
9. Bendix® WS-24™ Wheel Speed Sensors . . . . . . 8
10. SAE J2497 (PLC) Diagnostic Link . . . . . . . . . . . 9
11. SAE J1939 (CAN) Diagnostic Link . . . . . . . . . . . 9
12. Auxiliary I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
13. Bendix® ABS Flex™ Program . . . . . . . . . . . . . . 10
14. Customer Scratch Pad . . . . . . . . . . . . . . . . . . . 10
15. Power-Up Sequence . . . . . . . . . . . . . . . . . . . . .10
16. Odometer Function . . . . . . . . . . . . . . . . . . . . . . 10
17. Non-Standard Tire Size . . . . . . . . . . . . . . . . . . 11
18. Diagnostic Trouble Code Detection . . . . . . . . . 11
19. Partial ABS Shutdown . . . . . . . . . . . . . . . . . . . . 11
20. Blink Code Diagnostics . . . . . . . . . . . . . . . . . 11-12
21. Auxiliary Features . . . . . . . . . . . . . . . . . . . . . . . 12
22. Diagnostic Trouble Codes (DTCs) . . . . . . . . 13-17
Troubleshooting Section . . . . . . . . . . . . . . . . . . . 18-42

● A scratch-pad feature with up to 1,008 bytes of freely
definable read/write text space available for customer use.
1

● An extended data logging feature, including a resettable
drive recorder.
● A wide variety of electrical inputs/outputs (I/Os) allow
the customer to program auxiliary functions such as:
automatic Lift‑Axle Control (LAC); Integrated Speed
Switch (ISS); external load sensors; and Auxiliary
Design Language (ADL) for customized auxiliary
functions.
● A wide range of diagnostic tools for flexible
troubleshooting: Blink Codes; SAE J2497 (PLC); SAE
J1939(CAN) Diagnostics; the Bendix® Trailer Remote
Diagnostic Unit (TRDU); and the Bendix ® Trailer
Information Module.

● Support for SAE J2497 Power Line Carrier (PLC)
communication to the towing vehicle and diagnostics.
● Support for SAE J1939 (CAN) communication for
diagnostics and external devices.
● A pressure-equalizing valve in the sealed ECU housing
to give improved protection from water, etc.
● Serviceable nylon filters to help prevent foreign material
from entering the Control Port, Load Sensor Port, and
Supply Port.
● Locking dust cover to provide electrical connector and
cable protection.

GENERAL SAFETY GUIDELINES

READ AND
FOLLOW
THESE INSTRUCTIONS
2.WARNING! PLEASE
GENERAL
SAFETY
GUIDELINES
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.

Disconnect the electrical connectors from the ABS/
TRSP Controller before welding on the trailer.
2

Dielectric grease should be applied to electrical
connectors to help protect against moisture intrusion.

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 crash situation and may
cause data to be unavailable or irretrievable.

3. ANTILOCK BRAKE SYSTEM
(ABS) OPERATION
The Bendix® TABS‑6™ Advanced module uses wheel speed
sensors, a modulator relay valve (MRV), and an ECU to
optimize the contact between the tires and the road surface
during a braking event where excessive wheel slip – or
wheel lock-up – is detected.
When a situation is detected where the system needs to
intervene, the ECU will activate the MRV to apply controlled
brake pressure at the wheel ends.
The TABS‑6 Advanced module ECU is able to modulate
the brake pressure with greater speed and accuracy than
a driver.

Normal Braking
During normal braking the TABS‑6 Advanced module
functions as a standard relay valve. If the ECU does not
detect excessive wheel slip, it will not activate the ABS
system, and the vehicle will stop with normal braking.

Axle Control
Axle control uses the MRV to control the wheels at both
ends of a given axle (or multiple axles in cases where the
MRV is controlling several axles).

In the case of braking surfaces with poor overall traction
(e.g. roads that are worn, slippery, or are made of loose
gravel) – or braking surfaces with areas of poor traction
(e.g. asphalt roads with patches of ice) – axle control ABS
interventions will maintain the wheel that is not slipping at
just under the speed that will lock the wheel. The system
permits the other wheel (that is experiencing slippage)
temporary periods of wheel-lock during the intervention.
Axle control should not be used on fifth wheel dollies or
steerable axles.
When intervening on regular traction road surfaces, a
system configured for axle control performs similar to a
side control, two-modulator system.

ABS Fail-Safe
The TABS‑6 Advanced module is designed to react in
a fail-safe manner in the event of a system Diagnostic
Trouble Code (DTC). For example, if the ECU detects that
a sensor is not responding, an ABS system DTC will be set
and the TABS‑6 Advanced module will illuminate the trailer
ABS indicator lamp and revert to a fail-safe mode where
some, or all, Advanced ABS functions (including TRSP)
may not function. Even in cases where the ABS system
is completely disabled, the standard pneumatic brake
function of the vehicle will still be available, but without
the benefits of ABS. The TRSP feature is also disabled
with an active ABS system DTC. If the indicator lamp is
illuminated, always have the ABS system serviced at the
earliest opportunity.

For all NPT fittings, use of a thread sealant is
required. For NPTF fittings, the use of a thread
sealant is recommended. This can be a pre-applied
or a hand-applied sealant product (with PTFE).
When using a hand-applied sealant, use caution
so as not to over-apply. Always follow the fitting
manufacturer’s pre-applied or hand-applied thread
sealant recommendations. Use of PTFE tape is not
approved and will void the Bendix ABS/TRSP valve
warranty.

3/8-in. NPT Load Port 42 for Air Suspension
(Plugged for Non-Air Suspension or Spring
Suspension Sensor Vehicles)

3/8-in. NPT Control Port
with Integral Filter

Four 3/8-in.
NPT Delivery
Ports 21
(To Brake
Chambers)

3/4-in. NPT
Supply
Port 1

FIGURE 2 - PORTS USED

3

4. BENDIX® TRAILER ROLL STABILITY
PROGRAM (TRSP®) OPERATION
During a Bendix® TRSP® system intervention, the
vehicle automatically decelerates. The TABS‑6
Advanced module can slow the vehicle with or
without the driver applying the brake pedal, and even
when the driver applies the throttle.

Even with TRSP system-equipped vehicles, the driver
remains responsible for ensuring vehicle stability
during operation. The TRSP system only functions
within the limits of physics. The system can help
mitigate potential vehicle stability incidents, but
cannot prevent them in all cases. Other factors –
such as driving too fast for the road, traffic or weather
conditions, over-steering, an excessively high
vehicle Center of Gravity (CG), poor road conditions,
or insufficient vehicle maintenance – can cause
vehicle instability that is beyond the capability of
any stability system to mitigate.

The TRSP system should only be used on specific
vehicle platforms that have been validated and
approved by Bendix engineering.

The TRSP system is not approved for use on
combination vehicles (commonly referred to as
“doubles” or “triples”). The TABS‑6 Advanced
module shall not be installed on towing trailers
that can be used for “double” or “triple” trailer
applications (including B-trains).

For vehicles installed with spring suspension
systems, care must be taken to prevent damage to
the load sensor when lifting the trailer. The linkage
rod must be disconnected from the sensor’s rubber
boot whenever the frame of the trailer is lifted,
dropping the axle(s). This includes situations where
a jack is used on the rear bumper or when a crane is
used to lift the trailer.

4

Operating the vehicle with a damaged/disconnected
load sensor could lead to a serious accident. The
Bendix® Advanced Trailer ABS used on this vehicle
uses sensors, including the load sensor, to assist
the Trailer Roll Stability function.
The TRSP system reduces the risk of roll‑overs during
driving by automatic application of the service brakes when
the system detects potential rollover conditions. This is
accomplished with monitoring sensors both at the trailer
wheel-ends and within the TABS‑6 Advanced module. The
Bendix TRSP system reacts by applying the trailer service
brakes and slowing the vehicle combination.
The Bendix TRSP system uses the following sensors:
•

Lateral Acceleration:A lateral accelerometer is
located within the Bendix TABS‑6 Advanced module.
This sensor detects the lateral motion (or “roll”) of the
vehicle as it moves. The TABS-6 Advanced module
may be mounted either in line with or at right angles
to the main trailer chassis to function correctly – See
Troubleshooting section for full details of acceptable
installation locations. Do not attempt to change the
location of the module without contacting Bendix for
engineering approval. NOTE: Part numbers labeled
R001 and forward can only be mounted in the 0- or
180-degree orientations to function properly. See Figure
18 for more details.

•

Vehicle Speed: The TRSP system obtains information
about the vehicle speed and rate of acceleration from
the wheel speed sensors.

•

Axle/Bogie Load:The trailer’s axle load information is
obtained either by the use of:
(a) An integrated pressure sensor port (P42) of the
TABS‑6 Advanced module, where a direct reading
of the suspension air spring pressure is taken; or
(b) If configured for a mechanical spring deflection
sensor, a voltage reading that is proportional to the
spring deflection.

TRSP Intervention with Driver Actions
It is quite possible that the driver will also apply the brakes
before or during a TRSP intervention by the TABS‑6
Advanced module.In all cases, the Electronic Control
Unit (ECU) monitors the driver’s brake application and
compares that to the amount of braking the TRSP program
has calculated needs to be applied. The pressure delivered
to the brakes will always be the higher of the two values.

5. COMPONENTS
Installations of the TABS‑6 Advanced module use the
following components:

Use of cable ties/tie wraps to attach wheel speed
sensor leads to rubber hoses/jounce lines is not
approved. The hose may expand during braking
due to air pressure and the cable tie may not, so
the conductor material/insulation of the speed
sensor extensions may be damaged. Bendix instead
recommends only open-ended clips be used to hold
sensor leads to jounce lines.

Internal:
•

Electronic Control Unit (ECU):The ECU monitors the
speed sensor signals, lateral accelerometer sensor
signal and various pressure sensors (and if configured,
external spring deflection sensor) to determine when
ABS and/or TRSP intervention is required. When
needed, the ECU actuates the pressure modulator
valve to optimize the brake pressure. The ECU
monitors the system to detect and warn the driver of
any malfunctions.Diagnostic Trouble Codes (DTCs) are
stored in the ECU and can be reviewed to diagnose
the TABS‑6 Advanced module system.

•

Lateral Accelerometer Sensor:Lateral accelerometer
sensors sense the lateral movement of the trailer and
send an electrical signal directly proportional to the
trailer’s lateral acceleration to the ECU.

•

Internal Load Sensor:
For air suspension systems, the Load Sensor
Port (P42) must be plumbed to a fixed axle air ride
bellows. NOTE: The sensor must not be plumbed to a
lift‑axle bellows since they are not charged when the
axle is not being used. The function of this sensor is
to monitor the pressure and send an electrical signal
directly proportional to the trailer’s axle load to the ECU.

•

•

Brake Demand Pressure Sensor:This sensor
monitors the trailer service brake pressure being
applied by the driver and sends an electrical signal
directly proportional to the driver’s brake demand to
the ECU.
Brake Delivery Pressure Sensor:This sensor (P21)
monitors the trailer service brake pressure that is being
delivered to the wheel ends through, or by, the TABS‑6
Advanced module system and sends an electrical
signal directly proportional to the delivered trailer
service brake pressure to the ECU.

•

Modulator Relay Valve (MRV):An MRV is integrated
into the module and is controlled electrically by the
ECU to decrease, hold, or allow the full applied brake
pressure into the brake chamber to control the braking
torque at the wheels.

•

Modulator Relay Valve (MRV) Crack Pressure:The
Bendix TABS-6 ABS modulator relay valves are
available with nominal crack pressure of 4.5 ± 0.5 psi.
Previous models of TABS-6 modulator relay valves
came with a nominal crack pressure of 3.0 ± 0.5 psi.
Installation drawings are available that can provide
information on which version you have.

External:
•

Wheel Speed Sensors (WSS):Located at selected
hubs, wheel speed sensors detect the rotation of
individual wheels and send an electrical signal to the
ECU proportional to the rotational velocity. See Figure
3.

•

External Load Sensor:
For spring suspension systems, an external electrical
spring deflection sensor is installed – typically as close
to the center (±5 in.) as possible of an axle with linkage
attached to the center of the axle (but MUST NOT be
installed on a lift‑axle), See Figure 4. Vehicles with a
mechanical load sensor have the Load Sensor Port
(P42) used for sensing the air suspension system
plugged.
Sensor
Clamping
Sleeve
Acceptable
Logo-Stamped
Sleeves

90° Speed
Sensors

NOTE: Do Not Use
Previous WSS
Clamping Sleeves
That Have “BW”
in a Diamond

Straight Speed
Sensors

FIGURE 3 - BENDIX ® WS-24™ WHEEL SPEED SENSORS
FIGURE 4
- TYPICAL
EXTERNAL
LOAD SENSOR
INSTALLATION

Mounting