Bendix TABS-6 User Manual
Bendix® TABS-6 Trailer ABS Module
ECU Cover
(Sealed)
Integrated
Modulator
Relay Valve
3/4" NPT
Supply Port
Four (4) 3/8" NPT
Delivery Ports
(To Brake Chambers)
3/8" NPT Control
Port with
Integral Filter
ECU Connector
Cover
(Removable)
Through-holes
for Frame
(Chassis)
Mounting
Part Number
Label
(See Page 31)
ECU Pin-out Label
(See Page 31)
Wheel Speed
Sensor
Connectors
To Remove Cover
Slide Lock Tab
The ECU Connector
Varies for Standard and
Premium - See Chart
The Standard TABS‑6
Module uses a
5‑Pin Connector
The Premium TABS‑6
Module uses an
18‑Pin Connector
SD-13-4767
FIGURE 1 - TABS-6 STAndARd And PREmIUm mOdULES
INTRODUCTION
The Bendix® TABS-6 module is an integrated trailer ABS
controller and modulator for air-braked heavy-duty trailers,
semi-trailers and dollies. The module acts as a relay valve
during normal braking, but during ABS events, it will intervene
to help improve stability. All modules include an Electronic
Control Unit (ECU) and Modulator Relay Valve (MRV) which are
integrated into a single self-contained 2S/1M (two-sensor, one
modulator) trailer ABS unit. The Premium TABS-6 module is
auto-congurable to control more sensors and modulators (up to
4S/3M) from its default 2S/1M.
Bendix® TABS-6 modules also feature:
• Internal electrical connections to the primary MRV,
eliminating the need for external pigtail harnesses.
• Optional mounting to the service reservoir or to the chassis,
without additional brackets.
• Blink code diagnostics and support for advanced diagnostic
tools.
• Support for Power Line Carrier (PLC) communication to the
towing vehicle.
• A pressure equalizing valve in the sealed ECU housing to
give improved protection from water, etc.
• A locking dust cover to provide additional electrical connector
and cable protection.
• A serviceable nylon lter to help prevent foreign material
from entering the control port.
TABLE OF CONTENTS PAGE
General System Information
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Safe Maintenance Practices. . . . . . . . . . . . . . . . . . . 2
Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
Mounting Congurations. . . . . . . . . . . . . . . . . . . . . .2
PLC Communications. . . . . . . . . . . . . . . . . . . . . . . . 2
Wiring Harness (Pigtail) . . . . . . . . . . . . . . . . . . . . . . 3
Power and Ground . . . . . . . . . . . . . . . . . . . . . . . . . .4
ABS Indicator Lamp . . . . . . . . . . . . . . . . . . . . . . . . .4
Wheel Speed Sensors . . . . . . . . . . . . . . . . . . . . . . . 5
BR9235™ ABS Modulator Valve . . . . . . . . . . . . . . . .5
J1708/J1587 Diagnostic Link . . . . . . . . . . . . . . . . . .6
Auxiliary I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
ABS Flex™ Program . . . . . . . . . . . . . . . . . . . . . . . . .6
Customer Scratch Pad . . . . . . . . . . . . . . . . . . . . . . .6
Power-up Sequence. . . . . . . . . . . . . . . . . . . . . . . . . 6
ABS Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
Auto-Conguration . . . . . . . . . . . . . . . . . . . . . . . . . .8
Odometer Function. . . . . . . . . . . . . . . . . . . . . . . . . . 8
Non-standard Tire Size. . . . . . . . . . . . . . . . . . . . . . . 8
Diagnostic Trouble Code Detection . . . . . . . . . . . . .8
Blink Code Diagnostics. . . . . . . . . . . . . . . . . . . . . . .9
Bendix ABS Diagnostic Tools . . . . . . . . . . . . . . . . .13
Contacting Bendix. . . . . . . . . . . . . . . . . . . . . . . . . .14
Servicing the Module . . . . . . . . . . . . . . . . . . . . . . . 14
Removing the Module. . . . . . . . . . . . . . . . . . . . . . .14
Service Replacement using the Module. . . . . . . . . 15
Reinstallation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Leakage And Operational Tests . . . . . . . . . . . . . . . 15
ABS Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . 17-27
1
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. Nev e r ex ceed manufac t u r er ’s recommen d e d
pressures.
7. Ne v er connec t or disco n nect a h o se or lin e
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
components and kits. Replacement hardware,
tubing, hose, ttings, etc. must be of equivalent
size, type and strength as original equipment and
be designed specically 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.
replacement parts,
COMPONENTS
Installations of the TABS-6 Module typically utilize the
following components:
• Bendix® WS-24™ wheel speed sensors (2 or 4,
depending on conguration). Each sensor is installed
with a Bendix Sensor Clamping Sleeve. See page 5.
• Bendix® BR9235™ Pressure Modulator Valves (0, 1, or
2 depending on conguration). See page 5.
• Trailer-mounted ABS indicator lamp. See page 4.
• Pigtail wiring harness(es) as needed. See page 3.
MOUNTING CONFIGURATIONS
Tank (Nipple) Mount
The TABS-6 modules can be tank-mounted using a
schedule 80 (heavy gauge steel) 3/4" NPT nipple directly
between the trailer supply tank and the module's supply
port. A tank with a reinforced port must be used.
Frame (Chassis) Mount
The TABS-6 module provides through-holes for frame
mounting directly to the trailer frame rail or cross-member.
It is recommended to use two Grade 5 3/8-16 bolts, typical
length 5", torqued to 180-220 in-lbs.
POWER LINE CARRIER (PLC)
COMMUNICATIONS
Since March 1, 2001, all new towed vehicles transmit a
signal over the power line to an in-cab trailer ABS Indicator
Lamp. The signal, using a heavy vehicle industry standard
known as “PLC4Trucks,” is typically broadcast by the
trailer ABS ECU over the blue wire (power line) of the J560
connector. See Figures 2 and 3.
TABS-6 modules support PLC communications in accordance with SAE J2497.
Identifying and Measuring the PLC Signal
A TABS-6 module will continuously broadcast PLC
messages that indicate trailer ABS status. At power-up or
during a trailer ABS fault condition, the TABS-6 module will
signal the tractor ABS unit to illuminate the dash-mounted
trailer ABS indicator lamp.
Diagnostic tools are available that detect the presence
of a PLC signal and perform further system diagnostics
directly on the power line. For more information on these
diagnostic tools, contact Bendix or refer to your local
authorized Bendix dealer or distributor.
An oscilloscope can also be used to verify the presence
and strength of a PLC signal on the power line. The PLC
signal is an amplitude and frequency modulated signal.
Depending on the load on the power line, the amplitude of
the PLC signal can range from 5.0 mV p-p to 7.0 V p-p.
2
FIGURE 2 - POWER LInE WITHOUT PLC SIGnAL
5XXX...
5XXX...
EBA
D C
5XXX....
FIGURE 3 - POWER LInE WITH PLC SIGnAL
Suggested oscilloscope settings are (AC coupling, 1 volt/
div, 100 µsec/div). The signal should be measured on pin
7 of the J560 connector at the nose of the trailer.
PIGTAIL WIRING HARNESSES
Several pigtail wire harnesses are available to connect
the TABS-6 module with ABS and other trailer system
components. Pigtail harness are weather sealed at the
connector interface and are clearly labeled for proper
installation. Because of the over-molded design of the
TABS-6 module wiring harnesses, Bendix recommends that
the complete harness be replaced if damage or corrosion
occurs.
The following connector options may be present:
Modulator 2 (MOD2), Modulator 3 (MOD3), auxiliary,
diagnostic, and additional axle wheel speed sensors.
Note: All TABS-6 modules include the two primary wheel
speed sensor connections and therefore these are separate
from the pigtail harness.
ECU Connectors
Standard TABS-6 module ECU connectors use a TTMA
97-99 5-pin Packard Weather Pack connector for brake
light power, constant power, ground, the trailer-mounted
ABS indicator lamp and a single auxiliary input/output
(I/O).
Premium TABS-6 module ECU connectors use an 18-pin
Deutsch DT series connector for the same function as
above, plus additional modulators, wheel speed sensors
and auxiliary I/O’s.
5-Pin Power and
Indicator
Lamp (POWER/
WL)
3-Pin Modulator 2
(MOD2)
3-Pin Modulator 3
(MOD3) (Optional)
To TABS-6 Module
Pigtail
Modulator Extension Harness
To Diagnostic
Tool
4-Pin Diagnostic
2-Pin Additional
Wheel Speed
Sensor
Connectors
(SAL & SAR)
Auxiliary
(Optional)
To BR9235™ ABS Modulator
Relay Valve
To TABS-6 Module
Pigtail
5-Pin Power and
Indicator Lamp
(POWER/WL)
Optional
Diagnostic
18-Pin ECU Connector
Premium Pigtail Harness
(4S/2M with diagnostic)
5-Pin ECU
Connector
Standard Pigtail Harness
(2S/1M) with optional diagnostic
Diagnostic Tool Harness
To ECU or Pigtail
FIGURE 4 - ExAmPLES OF PIGTAIL WIRE HARnESSES AVAILABLE
Wheel Speed Sensor
Extension Harness
To WS-24™ Wheel
Speed Sensor
3
Power/ABS Indicator Lamp Connector
The TABS-6 module pigtail uses a TTMA RP 97-99 5-pin
Packard Weather Pack connector for brake light power,
constant power, ground and the trailer-mounted ABS
indicator lamp.
The Power/ABS indicator lamp lead of the pigtail harness
is available in several lengths to satisfy most installation
requirements (e.g. slider axles).
Wheel Speed Sensor Connectors
Two 2-pin connectors are provided for additional wheel
speed sensors for 4S ABS applications. These 2-pin
connectors are labeled Additional Sensor Left (SAL), and
Additional Sensor Right (SAR). Extension cables are
available in various lengths from Bendix.
ABS Modulator Connectors
On Premium TABS-6 module pigtail harnesses, one or two
modulator connectors are provided for trailers using two
or three modulators. These 3-pin connectors are labeled
MOD2 and MOD3. (Note: MOD1 designates the internal
modulator of the TABS-6 module). Remote modulator
harnesses are available in many lengths to satisfy most
installation requirements.
7-Pin 5-Pin 5-Pin 18-Pin
Circuit Trailer ABS ECU ECU
Conn. Conn. Conn. Conn.
Ignition Power
7 B B 6
PLC (Blue Wire)
Brake Light
Power 4 A A 12
(Red Wire)
Ground
1 E E 18
(White Wire)
Indicator Lamp
(White/green N/A D D 5
Wire)
CHART 2 – POWER And GROUnd
Diagnostic Connector
Premium TABS-6 module pigtail harnesses provide a 4pin diagnostic connection for a diagnostic tool to monitor
ECU ignition power, ground and data information. Remote
diagnostic cables are available from Bendix to provide a
standard J1708/J1587 diagnostic port at the side of the
trailer.
Auxiliary I/O Connector
Standard TABS-6 module pigtails provide an option for
a single auxiliary I/O. An optional auxiliary connector
provides a connection to the TABS-6 module auxiliary I/O
ECU pins. Premium ECU pigtails provides an option for
up to six auxiliary I/O’s.
POWER AND GROUND
Trailer electrical power is supplied to the TABS-6 module
from the ignition and brake light circuits. See Charts 1 and
2 for output values and pin locations.
Function Mode Value
Operating Range 8.0 to 16.0 VDC
ECU Active 135 mA @ 12 VDC
ABS Active 3.7 A @ 12 VDC
(1 Modulator)
FIGURE 5 - TRAILER-mOUnTEd ABS IndICATOR LAmP
ABS INDICATOR LAMP
Trailer-mounted Lamp
The TABS-6 module controls an ABS indicator lamp to show
the trailer ABS status. With power supplied by the towing
vehicle, the module illuminates the ABS indicator lamp by
providing a 12.0 VDC signal. (The other side of the lamp
is grounded.) The ABS indicator lamp output uses Pin D
of the 5-pin Standard module connector, and Pin 5 of the
18-pin Premium module connector.
Dash-mounted Lamp (PLC Controlled)
TABS-6 modules use SAE J2497 standards to support
Power Line Carrier (PLC) communication. The TABS-6
module transmits a signal over the power line to the towing
vehicle. This information is used by towing vehicle’s
ABS controller to know when to illuminate the trailer ABS
indicator lamp mounted on the dash.
The status of the trailer ABS is transmitted over the ignition
power wire (blue wire of the J560 connector), Pin B of the
5-pin Standard module connector, or Pin 6 of the 18-pin
Premium module connector.
ABS Active 5.2 A @ 12 VDC
(2 Modulators)
CHART 1 – VALUES FOR OUTPUTS
4
BENDIX® WS-24™ WHEEL SPEED SENSORS
Wheel speed data is provided to the TABS-6 module from
the WS-24™ wheel speed sensors (see Figure 6). 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 TABS-6 module receives the AC signal, which varies in
voltage and frequency as the wheel speed changes. (The
default setting expects a 100-tooth tone ring to be used.)
Vehicle axle and ABS control congurations determine if
two or four wheel speed sensors are required. See page
17 for electrical system schematics showing wheel speed
sensor connector pin locations.
A proper sensor installation is critical to correct ABS
operation.
Typically, the WS-24™ sensor is installed in mounting blocks
that are welded to the axle housing. WS-24™ wheel speed
sensors are protected by a stainless steel sheath. They
are designed to be used with beryllium copper clamping
sleeves (sometimes referred to as a “retainer bushing”,
“friction sleeve” or “clip”) (See Figure 6). The clamping
sleeve provides a friction t between the mounting block
bore and the WS-24™ sensor.
Sensor
90° Speed
Sensors
Straight Speed
Sensors
Clamping
Sleeve
Logo Stamped
into Sleeve
5. Engage the connectors, and push together until the
lock tab snaps into place.
NOTE: It is important for the wheel bearings to be
adjusted per the manufacturer's recommendations.
The friction t allows the WS-24™ sensor to slide back and
forth under force but to retain its position when the force
is removed. When the WS-24™ sensor is inserted all the
way into the mounting block and the wheel is installed on
the axle, the hub exciter contacts the sensor, which pushes
the sensor back. Also, normal bearing play will “bump” the
sensor away from the exciter. The combination of these
two actions will establish a running clearance or air gap
between the sensor and exciter.
Excessive wheel end play can result in diagnostic trouble
codes in cases where the sensor is pushed too far away
from the tone ring.
BENDIX® BR9235™ ABS MODULATOR
RELAY VALVES
Bendix® BR9235™ modulator relay valves (MRV) are
required when additional modulator relay valves are
needed for multichannel brake systems (e.g. 2S/2M, 4S/3M
ABS congurations).
The MRV is an electro-pneumatic control valve and is the
last valve that air passes through on the way to the brake
chambers. The normally-open hold solenoid and normallyclosed exhaust solenoid are activated to precisely modify
the brake pressure on command. During normal braking,
the BR9235™ MRV functions as a standard relay valve. As
brakes are applied or released by the driver, the control
signal from the tractor foot valve causes the BR9235™
MRV to apply proportional pressure to the trailer brake
chambers.
The BR9235™ MRV is available in both tank and bracket
mounting styles.
FIGURE 6 - BEndIx® WS-24™ WHEEL SPEEd SEnSORS
1. For increased corrosion protection we recommend
that a high-temperature rated silicon- or lithium-based
grease be applied to the interior of the mounting block,
the sensor, and to a new clamping sleeve.
2. Install the new clamping sleeve fully into the block,
with the retaining tabs toward the inside of the vehicle.
Please note that WS-24™ wheel speed sensors must
use the correct clamping sleeve to avoid problems
associated with reduced retention force, such as sensor
movement and resulting ABS trouble codes.
3. Gently push (DO NOT STRIKE) the sensor into the
mounting block hole until it bottoms out on the face of
the tone ring. Secure the cable lead wire to the knuckle/
axle housing 3-6 inches from the sensor.
4. Apply a moderate amount of dielectric non-conductive
grease to both the sensor connector and harness
connector.
3-Pin Modulator
Solenoid
Connector
3/8" NPT Supply
Port with Integral
Filter
Four 3/8" NPT Delivery Ports
(to Brake Chambers)
FIGURE 7 - BEndIx® BR9235™ mOdULATOR RELAY
VALVE
5
Tank (Nipple) Mounted
The BR9235™ MRV can be tank-mounted using a schedule
80 (heavy gauge steel) 3/4" NPT nipple directly between
the trailer supply tank and the supply port. A tank with a
reinforced port must be used.
Bracket (Chassis) Mounted
The BR9235™ MRV provides an option with a bracket
for frame mounting directly to the trailer frame rail or
crossmember. It is recommended to use two Grade 5,
3/8-16 bolts, torqued to 180 – 220 in-lbs.
J1708/J1587 DIAGNOSTIC LINK
The Premium TABS-6 module provides a J1708/J1587
diagnostic link with data and power to communicate with
the vehicle and various diagnostic tools. Diagnostics,
testing, conguration, data transfer and other functions can
be performed using this link. Diagnostic tools such as the
MPSI Pro-Link™ device and Bendix® ACOM™ Diagnostic
Software (version 4.0 and higher) support the TABS-6
Module.
Ignition power must be provided to the TABS-6 module for
the diagnostic link to be active.
AUXILIARY I/O
The Standard module provides for one auxiliary I/O
function.
The Premium module provides for up to ve auxiliary
functions and one additional ground. See Chart 3, below.
Bendix® ACOM™ Diagnostic Software (version 4.0 and
higher) supports the conguration of the TABS-6 module
auxiliary I/O’s.
ABS FLEX™ PROGRAM
The ABS Flex™ program uses Auxiliary Design Language
(ADL) to allow customized auxiliary functions to be carried
out by the TABS-6 module. Programs developed in the ABS
Flex™ program may be downloaded at the production line or
in the eld to control non-braking functions of the trailer.
Fo r example, A BS Flex™ p rogram c a n potenti a lly
communicate the status of: tire ination and/or temperature;
reefer temperature; load presence; slider pin position;
lift axle position; proximity/reverse alarm; and vehicle
weight.
ABS Flex™ programs monitor the auxiliary I/Os and/or the
SAE J1587 diagnostics and SAE J2497 PLC data links.
Contact your Bendix Account Manager to discuss an ABS
Flex™ program for your vehicle(s).
CUSTOMER SCRATCH PAD
The TABS-6 module has a Customer Scratch Pad feature
which allows the customer, or end-user, to store up to 756
bytes of information. This information can then be read
using the Bendix® ACOM™ Diagnostic Software (version
4.0 and higher).
If additional scratch pad space is needed, this storage
space can be expanded to 1K (1,008 bytes total of data).
Contact Bendix for further details.
POWER-UP SEQUENCE
At power-up, the TABS-6 module performs a series of selfchecks that can assist a technician to determine the ABS
system status and conguration.
Name ECU ECU Pin Auxiliary Functions Default Function
• High-Side Driver… or Digital Input…
AUX Standard C None
or • Analog Input
AUX1 Premium 16 • High-Side Driver… or Digital Input Modulator 3 (MOD3)
Hold Solenoid
AUX2 Premium 10 • High-Side Driver… or Digital Input Modulator 3 (MOD3)
Release Solenoid
AUX3 Premium 15 • High-Side Driver… or Digital Input Modulator 2 (MOD2)
Hold Solenoid
AUX4 Premium 9 • High-Side Driver… or Digital Input Modulator 2 (MOD2)
Release Solenoid
AUX5 Premium 4 • Low-Side Driver… or Analog Input Modulator 3 (MOD3)
Common
AUX6 Premium 3 • High-Side Driver… or Digital Input J1587 Diagnostic Power
CHART 3 – AUxILIARY I/OS And dEFAULT FUnCTIOnS
6
ABS System
Power
Application
Status Indicators
0.5
Trailer-mounted ABS
Indicator Light
Dash-mounted Trailer
ABS Indicator Light (PLC
Detected)*
Dash-mounted 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 8 - TRAILER ABS LAmP START UP SEqUEnCE
ON
OFF
ON
OFF
ON
OFF
Trailer ABS indicator lamp
At power-up without detected faults, the trailer ABS
indicator lamp will turn on for 2.5 seconds as a bulb check
and then turn off. See Figure 8.
If a PLC-ready towing vehicle and trailer are powered at
the same time, the TABS-6 module will also trigger a bulb
check on the dash-mounted trailer ABS indicator lamp.
Modulator Chuff Test at Power-Up
At power-up, the TABS-6 module activates a modulator
chuff test. This electrical and pneumatic ABS modulator
test can help the technician identify problems with
modulator installations and/or wiring.
With brake pressure applied, a properly installed modulator
will cause ve rapid audible chuffs of air pressure. If
additional modulators are installed, the TABS-6 module
activates 5 chuffs at the internal modulator (MOD1) then
for each additional modulator in sequence (e.g. MOD1,
then MOD2, and then MOD3). The chuff sequence is
then repeated.
If the modulator is wired incorrectly, the modulator will only
produce one chuff, or no chuff at all. If an issue is detected
during the modulator chuff test, compare the modulator
wiring and plumbing to the TABS-6 module’s electrical
system schematic (see page 17) and make repairs.
2.0
2.5
3.0 (sec.)1.5
ABS OPERATION
The TABS-6 module uses wheel speed sensors, modulator
relay valves and an ECU to control trailer wheels by axle
or by side. By monitoring individual wheel turning motion
during braking, and adjusting or pulsing the brake pressure
at each wheel, the TABS-6 module is able to optimize slip
between the tires and the road surface. When excessive
wheel slip, or wheel lock-up, is detected, the ECU will
activate the Pressure Modulator Valves to modulate
braking pressure at the wheel ends. The ECU is able to
pump the brakes on individual wheels (or pairs of wheels),
independently, and with greater speed and accuracy than
a driver.
Axle Control
TABS-6 module axle control uses a single modulator relay
valve to control wheels on both sides of a given axle or
axles. In the case of an ABS event on road surfaces with
poor traction (worn, slippery, or loose gravel roads) or areas
of poor traction, (e.g. asphalt road surfaces with patches of
ice), axle control will maintain the wheel that is not slipping
at just under the speed that will lock the wheel. Temporary
periods of wheel lock are permitted on the other wheel that
is experiencing slippage.
Axle control should not be used on 5th wheel dollies or
steerable axles. When braking on even surfaces, an
axle-control system will perform similar to a side control,
two-modulator system. Axle control is available in 2S/1M,
2S/2M and 4S/2M installations, and for Modulator 3
(MOD3) in a 4S/3M installation.
Dolly-Axle Control (Select Low)
TABS-6 module dolly-axle control uses a single ABS
modulator valve to control wheels from both sides of a
given axle or axles. In the case of an unbalanced braking
surface, (e.g. asphalt road surfaces with patches of ice),
dolly axle control will control the low coefcient (slipping)
wheel just under the lock limit. Vehicle stability is assisted
by not allowing the high coefcient wheel (where traction
is still being maintained) to sustain wheel lock.
When braking on even surfaces, a dolly axle control system
will perform similar to side control or axle control system.
Dolly axle control is only available in 2S/1M installations.
Side Control
The TABS-6 module uses a single modulator relay valve
to control one or more wheels on a given vehicle side. In
the case of an unbalanced braking surface, the side control
will individually control wheels on each side just under the
point where they would lock up.
Side control is available in 2S/2M and 4S/2M installations,
and for the internal modulator (MOD1) and Modulator 2
(MOD2) in the 4S/3M installation.
Normal Braking
During normal braking, the TABS-6 module functions as a
standard relay valve. If the ECU does not detect excessive
wheel slip, it will not activate ABS control, and the vehicle
stops with normal braking.
7
AUTO-CONFIGURATION
The Standard TABS-6 module is available only in the 2S/1M
ABS conguration and does not use auto-conguration.
For the Premium TABS-6 module, the default ABS
conguration is 2S/1M. At power-up, if a Premium ECU
detects additional sensors and modulators it will perform an
auto-conguration. Auto-conguration only adjusts upward
(e.g. 2S/2M Side to a 4S/2M Side conguration).
Additional detected components that do not conform to a
legitimate conguration will generate the appropriate faults.
If the vehicle begins moving before the new conguration
has been accepted, the reconguration will not take place
at this time.
Additional Components
Default
Sensors Modulators
- - 2S/1M (Dolly-Axle)
- 1 to 2S/2M (Side)
2S/1M
2 1 to 4S/2M (Side)
Dolly Axle
2 2 to 4S/3M (Side/Axle)
- - 2S/1M (Axle)
2S/1M
- 1 to 2S/2M (Axle)
Axle
2 1 to 4S/2M (Axle)
CHART 4 – PREmIUm TABS-6 mOdULE AUTOCOnFIGURATIOn mATRIx
Auto-Conguration
ODOMETER FUNCTION
Odometer
The TABS-6 module includes an odometer function to
provide a means of storing the accumulated mileage of the
vehicle. The mileage is computed by utilizing information
calculated from the vehicle wheel speeds.
This feature is accurate to within 0.62 miles per power-up
and will typically store mileage up to 1,000,000 miles. The
mileage can be displayed using PC diagnostics or through
blink codes.
Whenever the module is towed using a pre-1997 tractor,
the electronic odometer does not function, and the mileage
can be considered out-of-calibration.
Trip Counter
The module provides a counter to record the trip mileage.
The feature is accessed through PC or handheld diagnostic
tools.
Service Interval
The TABS-6 module provides a feature that can be used
to indicate a service interval for the trailer. The service
interval can be accessed via PC or hand-held diagnostic
tools. If congured, the TABS-6 module can ash the
indicator lamp when the vehicle is at standstill to indicate
when the service interval has been exceeded.
NON-STANDARD TIRE SIZE
The module allows for tire rolling radius and tone ring
tooth count parameters to be set for each axle using a
diagnostic tool. These adjustments may be necessary for
the module to accurately calculate the vehicle velocity and
odometer mileage. Wheels of the same axle must be set
to the same rolling radius and tone ring tooth count. In
most cases, these parameters are set by the trailer OEM
and do not need to be adjusted. In the case of a service
replacement unit, always check that these parameters are
set to match the vehicle.
The tire-rolling radius is defaulted to 500 revs/mile and can
be adjusted from 300 to 700 revolutions per mile. Refer to
the manufacturer’s tire specication for correct values.
Tone ring tooth count is defaulted to 100 teeth and can be
set to 60 to 140 teeth.
DIAGNOSTIC TROUBLE CODE DETECTION
The TABS-6 module contains self-testing diagnostic
circuitry that monitors the ABS components and wiring.
When the module senses an erroneous system condition,
it activates the external trailer-mounted ABS indicator lamp,
disables all or part of the affected ABS functions, and it
stores the fault code in memory, even when the power is
removed. The module also uses PLC communications to
send the system status to the towing vehicle.
Fo r some t r ouble c odes, t h e TABS-6 module w i ll
automatically reset (“self-heal”) the active diagnostic
trouble code when the error is corrected (e.g. when a
wheel speed sensor is re-aligned). However, repeated
occurrences of a given trouble code can cause the code to
“latch” - that is, be retained as active, even if the condition
is only intermittent. Once the code is latched, a manual
reset will be necessary. Technicians can use these latched
codes to assist them in troubleshooting intermittent errors.
After the problem is repaired, trouble codes can be reset
using blink code diagnostics or with a diagnostic tool.
When a trouble code self-heals or is manually reset, the
code remains stored in the ECU memory. This trouble
code history can be retrieved using blink code diagnostics
or with a diagnostic tool.
8
PARTIAL ABS SHUTDOWN
Depending on the trouble code detected, the ABS ECU
partly or completely disables the ABS functionality.
The trailer ABS system, for vehicles that only have one
modulator, are disabled by any single fault. In the case of
vehicles with two or three modulators, depending on the
trouble code, the trailer ABS system may still provide some
level of ABS function on axles/wheels that are not affected
by the fault, but the ABS indicator lamp will remain on. In
cases where the ABS is completely disabled, the vehicle
reverts to normal braking (without ABS interventions).
Always repair ABS shutdowns at the earliest opportunity.
ECU Diagnostic Trouble Codes
All ABS functions are completely disabled. The system
reverts to normal braking.
Voltage Diagnostic Trouble Code
While voltage is out of range, the ABS functionality is
disabled and the system reverts to normal braking. When
the correct voltage level is restored, full ABS is typically
available again. The operating voltage range is 8.0 to
16.0 VDC.
BLINK CODE DIAGNOSTICS
The TABS-6 module provides diagnostic and conguration
functions through blink code diagnostics. This means that
the technician, even without diagnostic tools, can read a
series of ABS indicator lamp blinks to diagnose the trouble
codes being generated.
The blink code diagnostics mode is entered by providing
constant power to the ignition circuit and toggling the
brake light power input three times. With a parked towing
vehicle attached, this is done by applying ignition power
and after the power up sequence is complete, depressing
and releasing the brake pedal three or more times, see
below for chart.
Depending on the blink code mode activated, the TABS-6
module will blink the trailer-mounted ABS indicator
lamp to display: active fault codes; fault code history;
ABS congurations; and odometer mileage. Blink code
diagnostics can also be used to reset active fault codes.
With Ignition Power Blink Code
Applied, Cycle Brake Action
Light Power
Wait until after the modulator chuff test before activating
the brake light power. Following a single display of all
available messages, the ABS indicator lamp will remain on
for ve seconds and then return to normal operating mode.
Blink code diagnostics can only be activated following a
power-up, where wheel speeds have not been detected. If
the vehicle moves during blink code diagnostics mode, the
module will cancel the blink code diagnostics and return to
normal operating mode.
Blink code diagnostics must be activated within the rst 15
seconds of ignition power being applied.
If brake light power is continuously applied for greater than
ve seconds, blink code diagnostics will be disabled until
the next time the ignition power is cycled.
Display Active Diagnostic Trouble Codes
To display active codes, apply ignition power and depress
/ release the brake pedal 3 times within 15 seconds.
Following activation, there will be a 5-second delay followed
by a blink code display of all active fault codes. (See pages
10-12 for more information.)
Display Diagnostic Trouble Code History
To display trouble code history, apply ignition power
and depress / release the brake pedal 4 times within 15
seconds. Following activation, there will be a 5-second
delay followed by a blink code display of all history fault
codes. (See pages 10-12 for more information.)
Reset Active Diagnostic Trouble Codes
To reset active codes, apply ignition power and depress
/ release the brake pedal 5 times within 15 seconds.
Following activation, there will be a 5-second delay followed
by a blink code message of:
1-1, (System Fully Operational - No Codes Detected) or a
blink code display of all remaining active fault codes.
The ABS indicator lamp will stay on if active DTCs are still
present.
Resetting active fault codes with blink code diagnostics
does not clear information from trouble code history. Both
blink code diagnostics or diagnostic tools can retrieve
trouble code history, but only diagnostic tools can erase
this information.
3 times Display Active DTCs
4 times Display Inactive DTCs
5 times Clear Active DTCs
6 times Display Conguration
7 times Display Odometer Mileage
8 times Reset Conguration
CHART 5 – BLInk COdE InFORmATIOn
9
Display Conguration
To check the ABS conguration, apply ignition power
and depress / release the brake pedal 6 times within 15
seconds. Following activation, there will be a 5-second
delay followed by a blink code display of the module's
current ABS conguration.
1st Digit Sensors
2 2 Sensors
4 4 Sensors
2nd Digit Modulators
1 1 Modulator
2 2 Modulators
3 3 Modulators
3rd Digit ABS Control Mode
1 Axle
2 Side
3 Dolly-Axle
4 MOD1 Axle - MOD2 Dolly-Axle
5 MOD1 Axle - MOD2 Lift Axle
6 Side (MOD1, MOD2) - MOD3 Dolly-Axle
CHART 6 – ABS COnFIGURATIOnS
Display Odometer Mileage
To display the trailer odometer mileage, apply ignition
power and depress / release the brake pedal 7 times within
15 seconds. Following activation, there will be a 5-second
delay followed by a blink code display of the odometer
information (x1000).
Example: 152,431 miles will be displayed as: 152 (x1000)
or 1 blink (pause), 5 blinks (pause), 2 blinks.
Zeros will be displayed by the ABS indicator lamp strobing
twice.
Odometer mileage cannot be altered with blink code
diagnostics. Complete odometer information can be
retrieved using a diagnostic tool.
Resetting ABS Conguration
To reset the ABS conguration to the default conguration,
apply ignition power and depress / release the brake
pedal 8 times within 15 seconds. Following activation,
the TABS-6 ABS conguration will reset to the default ABS
conguration (2S/1M).
Diagnostic Trouble Codes (DTCs)
1st 2nd Fault Description Repair Information J1587 J1587
Digit Digit (SID) (FMI)
1 1 No faults • ABS system fully operational – no faults detected 1 0
WHEEL SPEED SENSORS (WSS)
2 1 SL Sensor signal valid - large air gap 1 0
3 1 SR Sensor signal valid - large air gap 2 0
4 1 SAL Sensor signal valid - large air gap 3 0
5 1 SAR Sensor signal valid - large air gap 4 0
2 2 SL Sensor signal valid - loss of signal 1 1
3 2 SR Sensor signal valid - loss of signal Dynamic Wheel Speed Sensor Fault. 2 1
4 2 SAL Sensor signal valid - loss of signal Go to Section G, on Page 29. 3 1
5 2 SAR Sensor signal valid - loss of signal 4 1
2 3 SL Sensor signal valid – noisy 1 2
3 3 SR Sensor signal valid – noisy 2 2
4 3 SAL Sensor signal valid – noisy 3 2
5 3 SAR Sensor signal valid – noisy 4 2
2 4 SL Sensor shorted or open 1 4 or 5
3 4 SR Sensor shorted or open Static Wheel Speed Sensor Fault. 2 4 or 5
4 4 SAL Sensor shorted or open Go to Section G, on Page 29. 3 4 or 5
5 4 SAR Sensor shorted or open 4 4 or 5
2 5 SL Tire diameter out of range • Verify correct tire size as desired. 1 13
3 5 SR Tire diameter out of range • Verify proper tire ination. 2 13
4 5 SAL Tire diameter out of range • Verify correct number of exciter ring teeth. 3 13
5 5 SAR Tire diameter out of range • Verify that the ECU has the proper tire size settings. 4 13
4 6 SAL Sensor conguration error • Verify correct ABS conguration using blink codes 3 13
or other diagnostic tools.
5 6 SAR Sensor conguration error • If needed, reset to the default ABS conguration and 4 13
power-up to initiate auto-conguration.
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