Bendix Commercial Vehicle Systems 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-conﬁ gurable 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 ﬁ 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 Conﬁ gurations. . . . . . . . . . . . . . . . . . . . . . 2

PLC Communications. . . . . . . . . . . . . . . . . . . . . . . . 2

Wiring Harness (Pigtail) . . . . . . . . . . . . . . . . . . . . . . 3

Power and Ground . . . . . . . . . . . . . . . . . . . . . . . . . .4

ABS Indicator Lamp . . . . . . . . . . . . . . . . . . . . . . . . .4

Wheel Speed Sensors . . . . . . . . . . . . . . . . . . . . . . . 5

BR9235

™

ABS Modulator Valves . . . . . . . . . . . . . . . 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-Conﬁ guration . . . . . . . . . . . . . . . . . . . . . . . . . .8

Odometer Function. . . . . . . . . . . . . . . . . . . . . . . . . . 8

Non-standard Tire Size. . . . . . . . . . . . . . . . . . . . . . . 8

Diagnostic Trouble Code Detection . . . . . . . . . . . . .8

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

Blink Code Diagnostics. . . . . . . . . . . . . . . . . . . . . . .9

Diagnostic Trouble Codes (DTCs) . . . . . . . . . . . . . 10

Using Hand-Held or PC-Based Diagnostics. . . . . . 13

Bendix ABS Diagnostic Tools . . . . . . . . . . . . . . . . .13

Contacting Bendix. . . . . . . . . . . . . . . . . . . . . . . . . .14

Servicing the TABS-6 Module . . . . . . . . . . . . . . . . .15

Removing the TABS-6 Module . . . . . . . . . . . . . . . . 15

Service Replacement of Other ABS Controllers . . .15

Reinstallation of the TABS-6 Module . . . . . . . . . . . 15

Leakage And Operational Tests . . . . . . . . . . . . . . . 16

ABS Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . 17-31

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 a Bendix 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 components and kits. Replacement hardware, tubing, hose, ﬁ ttings, etc. must be of equivalent size, type and strength as original equipment and be designed speciﬁ cally 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 Automatic 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.

brand 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 conﬁ guration). Each sensor is installed with a Bendix Sensor Clamping Sleeve. See page 5.

• Bendix

BR9235™ Pressure Modulator Valves (0, 1, or

2 depending on conﬁ guration). 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.

FIGURE 2 - POWER LINE WITHOUT PLC SIGNAL

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.

2-Pin Additional

Wheel Speed

Sensor

5-Pin Power and

Indicator

Lamp (POWER/

WL)

3-Pin Modulator 2

(MOD2)

4-Pin Diagnostic

3-Pin Modulator 3 (MOD3) (Optional)

5XXX....

To TABS-6 Module

Pigtail

Modulator Extension Harness

To Diagnostic

Tool

5XXX...

Diagnostic Tool Harness

Connectors

(SAL & SAR)

Auxiliary

(Optional)

To BR9235

Relay Valve

To TABS-6 Module

™

ABS Modulator

Pigtail

5-Pin Power and

Indicator Lamp

(POWER/WL)

To ECU or Pigtail

FIGURE 4 - EXAMPLES OF PIGTAIL WIRE HARNESSES AVAILABLE

Optional

Diagnostic

Wheel Speed Sensor

Extension Harness

18-Pin ECU Connector

Premium Pigtail Harness

(4S/2M with diagnostic)

5XXX...

Standard Pigtail Harness

(2S/1M) with optional diagnostic

5-Pin ECU Connector

™

To WS-24

Speed Sensor

Wheel

EBA

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

(Blue Wire)

PLC

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 4-pin 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

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 conﬁ gurations 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 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 ﬁ t between the mounting block bore and the WS-24™ sensor.

90° Speed

Sensors

sensor is installed in mounting blocks

Sensor

Clamping

Sleeve

Logo Stamped

into Sleeve

Straight Speed

Sensors

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 ﬁ 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 conﬁ gurations).

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

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, conﬁ guration, 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 ﬁ ve auxiliary functions and one additional ground. See Chart 3, below.

Bendix® ACom® Diagnostic Software (version 4.0 and higher) supports the conﬁ guration 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 ﬁ eld to control non-braking functions of the trailer.

™

For example, ABS Flex

program can potentially communicate the status of: tire inﬂ ation 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 conﬁ guration.

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

ABS System

Power

Application

Status Indicators

2.0

2.5

3.0 (sec.)1.5

0.5

Trailer-mounted ABS

Indicator Lamp

Dash-mounted Trailer

ABS Indicator Lamp

(PLC Detected)*

Dash-mounted Trailer

ABS Indicator Lamp

(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

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 ﬁ 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.

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 coefﬁ cient (slipping) wheel just under the lock limit. Vehicle stability is assisted by not allowing the high coefﬁ cient 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.

AUTO-CONFIGURATION

The Standard TABS-6 module is available only in the 2S/1M ABS conﬁ guration and does not use auto-conﬁ guration.

For the Premium TABS-6 module, the default ABS conﬁ guration is 2S/1M. At power-up, if a Premium ECU detects additional sensors and modulators it will perform an auto-conﬁ guration. Auto-conﬁ guration only adjusts upward (e.g. 2S/2M Side to a 4S/2M Side conﬁ guration).

Additional detected components that do not conform to a legitimate conﬁ guration will generate the appropriate faults. If the vehicle begins moving before the new conﬁ guration has been accepted, the reconﬁ guration 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-Conﬁ guration

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 hand-held 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 conﬁ gured, the TABS-6 module can ﬂ 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 speciﬁ cation for correct values.

Tone ring tooth count is defaulted to 100 teeth and can be set from 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.

For some trouble codes, the TABS-6 module will 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.

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 conﬁ guration 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 chart 5 below.

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 conﬁ gurations; 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 ﬁ 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 ﬁ rst 15 seconds of ignition power being applied.

If brake light power is continuously applied for greater than ﬁ 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 Conﬁ guration

7 times Display Odometer Mileage

8 times Reset Conﬁ guration

CHART 5 – BLINK CODE INFORMATION

Display Conﬁ guration

To check the ABS conﬁ guration, 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 conﬁ guration.

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 Conﬁ guration

To reset the ABS conﬁ guration to the default conﬁ guration, apply ignition power and depress / release the brake pedal 8 times within 15 seconds. Following activation, the TABS-6 ABS conﬁ guration will reset to the default ABS conﬁ guration (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 inﬂ ation. 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 conﬁ guration error • Verify correct ABS conﬁ guration using blink codes 3 13 or other diagnostic tools. 5 6 SAR Sensor conﬁ guration error • If needed, reset to the default ABS conﬁ guration and 4 13 power-up to initiate auto-conﬁ guration.

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