WABCO 2S/2M User manual

TRAILER iABS
2S/2M, 4S/2M AND 4S/3M
INSTALLATION INSTRUCTIONS
TP18006

3
Table of Contents
Edition 2
05.2020
TP18006 1 (en)
This publication is not subject to any update service. Information contained in this
publication was in effect at the time the publication was approved for printing and is
subject to change without notice or liability. WABCO reserves the right to revise the
information presented or to discontinue the production of parts described at any time.
Table of Contents
1 General Information ......................................................................................................................................... 4
2 Safety Information............................................................................................................................................ 6
3 Important Information...................................................................................................................................... 6
4 Preparation ....................................................................................................................................................... 7
5 Installation ........................................................................................................................................................ 9
5.1 Install the ECU/Dual Modulator Valve Assembly..................................................................................... 9
5.2 End of Line Testing ............................................................................................................................... 23
6 Appendix I....................................................................................................................................................... 31
6.1 Installing Sensors on Non-ABS-Prepped Axles .................................................................................... 31
7 Appendix II...................................................................................................................................................... 33
7.1 Cable Strain Relief Guidelines .............................................................................................................. 33
8 Appendix III..................................................................................................................................................... 37
8.1 Vehicle Electrical Grounding Guidelines ............................................................................................... 37
9 Appendix IV ................................................................................................................................................... 38
9.1 Parts and Variant List............................................................................................................................ 38

4
General Information
1 General Information
Symbols used in this document
DANGER
Description of an immediate situation which will result in irreversible injury or death if the warning is
ignored.
WARNING
Description of a possible situation which may result in irreversible injury or death if the warning is
ignored.
CAUTION
Description of a possible situation which may result in irreversible injury if the warning is ignored.
NOTICE
Description of a possible situation which may result in material damage if the warning is ignored.
Important information, notes and/or tips
Reference to information on the internet
1. Action step
- Action step
Consequence of an action
List
•List
Note on the use of a tool/WABCO tool

5
General Information
How to Obtain Additional Maintenance, Service and Product Information
If you have any questions about the material covered in this publication, or for more information about
the WABCO product line, please contact WABCO Customer Care Center at 855-228-3203, by email at
[email protected], or visit our website: www.wabco-na.com.
Refer to the latest iABS Maintenance Manual MM19001. To obtain this publication, visit our website at
wabco-na.com/literature, or call WABCO North America Customer Care at 1-855-228-3203.
Refer to the Society of Automotive Engineers (SAE) website to find all current SAE documents and
standards applicable to WABCO products (such as SAE J447 and SAE J908 at www.sae.org).
Refer to the National Highway Traffic Safety Administration (NHTSA) website to find all current documents
referenced in the manual at www.nhtsa.gov.
WABCO TOOLBOX PLUS™Software
The TOOLBOX PLUS™ Software provides PC diagnostics for WABCO products can be purchased and
downloaded from https://wabco.snapon.com. For complete instructions for using TOOLBOX PLUS™ refer
to User’s Guide MM19047. To obtain this literature, visit www.wabco-na.com/literature.
WABCO Academy
https://www.wabco-academy.com/home/
WABCO Online product catalog
http://www.wabco-customercenter.com
Your direct contact to WABCO
WABCO North America LLC
WABCO USA LLC
1220 Pacific Drive
Auburn Hills, MI 48326
Customer Care Center: [phone]
www.wabco-na.com

6
Important Information
2 Safety Information
Provisions for a safe work environment
Only trained and qualified auto technicians and auto mechanics may carry out work on the vehicle.
Read this publication carefully.
Follow all warnings, notices and instructions to avoid personal injury and property damage.
Always abide by the vehicle manufacturer’s specifications and instructions.
Observe all accident regulations of the respective company as well as regional and national regulations.
The workplace should be dry, sufficiently lit and ventilated.
Use personal protective equipment if required (safety shoes, protective goggles, respiratory protection
and ear protectors).
Read and observe all Danger, Warning and Caution hazard alert messages in this publication. They provide
information that can help prevent serious personal injury, damage to components, or both.
WARNING
To prevent serious eye injury, always wear safe eye protection when you perform vehicle
maintenance or service.
WARNING
Park the vehicle on a level surface. Block the wheels to prevent the vehicle from moving. Support the
vehicle with safety stands. Do not work under a vehicle supported only by jacks. Jacks can slip or fall
over. Serious personal injury and damage to components can result.
3 Important Information
Use only genuine WABCO components. Other manufacturers’ parts are not designed for use with a
WABCO ABS system and may not function correctly.
WABCO recommends that a control line filter, part number 432-500-005-0, be installed on the air system’s
control line, upstream of the ABS ECU/valve assembly.

7
Preparation
4 Preparation
1. Before beginning the installation procedure, inspect the ECU/dual modulator valve assembly for
damage that may have occurred during shipping or storage.
Look for damaged or broken connectors.
Do not install a damaged ECU/dual modulator valve assembly. Notify your supervisor, or contact
WABCO if there is any apparent damage.
2. Have the following installation material available.
WABCO Components:
ECU/dual modulator valve assembly
ABS relay valve and relay valve extension cable (3M system only)
Power cable or power/diagnostic cable
Sensor extension cables (two pieces for 2S systems, four pieces for 4S systems)
ABS sensors (two or four) for non-ABS prepped axles
ABS Indicator Label (TP-95172)
Non-WABCO Components:
5/8-inch O.D. nylon tubing for supply (frame mount)
Pipe plug (3/4-inch NPT)
Schedule 80 hex pipe nipple (3/4-inch NPT) for air tank mounts or two Grade 8 bolts (3/8-inch)
and prevailing torque nuts for frame mounts
ABS sensor clip lubricant (the following are approved by WABCO):
•Mobilith SHC-220 (Mobil)
•TEK 662 (Roy Dean Products)
•Staburags NBU 30 PTM (Kluber Lubrication)
•Valvoline EP 633
SAE-standard, DOT-approved sealing paste
ABS indication lamp (to ensure correct lamp operation, use an incandescent-type DOT-approved
lamp, or an LED with integral load resistor)
All WABCO component part number information can be found in Appendix IV.
End of line testing must be done after all installations. WABCO recommends using TOOLBOX PLUS™
Software to perform this testing. If you do not have TOOLBOX PLUS™ Software, this bulletin also includes
instructions for testing without the software. The TOOLBOX PLUS™ Software can be purchased and
downloaded from www.wabco-snapon.com.

8
Preparation
3. Study the ECU/single modulator valve assembly. Note the location of the various ports and electrical
connections on the ECU. Figure 1, Figure 2, and Figure 3.
Fig. 1
4014012a
POWER SUPPLY
ABS SENSOR F
ABS SENSOR D
GIO 1
SUBSYSTEM/
DIAGNOSTIC
3rd MODULATOR/GIO 2
ABS SENSOR E
ABS SENSOR C
Fig. 2
4014013a
BOTTOM VIEW
DELIVERY
PORTS
DELIVERY
PORTS
EXHAUST
PORT
POWER
SUPPLY
SUBSYSTEM/
DIAGNOSTIC
GIO 1 3RD MODULATOR/
GIO 2
ABS
SENSOR
D
ABS
SENSOR
F
ABS
SENSOR
C
ABS
SENSOR
E
Fig. 3
4014007b
CONTROL
PORT
DELIVERY PORTS 2.2
DELIVERY
PORTS 2.1
SUPPLY
PORT

9
Installation
5 Installation
5.1 Install the ECU/Dual Modulator Valve Assembly
The assembly may be mounted on the air tank or on the cross member of the vehicle.
5.1.1 Tank-Mounted
Refer to Figure 4.
Fig. 4
ECU/DUAL MODULATOR VALVE MOUNTED WITH
CONTROL PORT FACING FRONT OFTRAILER
(TANK-MOUNTED)
ECU/DUAL MODULATOR VALVE MOUNTED WITH
CONTROL PORT FACING REAR OF TRAILER
4013982a
PLUG
UNUSED
PORT
Exhaust port
must face DOWN.
POWER SUPPLY
ABS SENSOR F ABS SENSOR D GIO 1
SUBSYSTEM/ DIAGNOSTIC
3rd MODULATOR/GIO 2
ABS SENSOR E
ABS SENSOR C
POWER SUPPLY
ABS SENSOR F
ABS SENSOR D
GIO 1
SUBSYSTEM/
DIAGNOSTIC
3rd MODULATOR/GIO2
ABS SENSOR E
ABS SENSOR C

10
Installation
WARNING
You must use a Schedule 80 hex nipple (3/4-inch NPT) to mount the ECU/dual modulator valve
assembly securely to the air tank to avoid possible serious personal injury and damage to the
component.
1. Use a 3/4-inch NPT Schedule 80 hex nipple to attach the ECU/dual modulator valve assembly to a
reinforced air tank. Apply SAE-standard, DOT-approved sealing paste to either the first few threads or
over the whole length. Hand-tighten it with a minimum of 2.5 turns. Note if a minimum of 2.5 turns
cannot be achieved, remove and inspect.
NOTICE
WABCO does not recommend the use of a vise when installing the hex nipple. Use of a vise may
cause overclamping. Overclamping may damage the internal components of the ECU/dual modulator
valve assembly.
2. Use a 3/4-inch NPT pipe plug to plug the unused supply port. Apply SAE-standard, DOT-approved
sealing paste to either the first few threads or over the whole length. Pipes with pre-applied thread
sealant may also be used.
3. Rotate and tighten the ECU/dual modulator valve assembly a minimum of 3 turns and verify the
exhaust port faces DOWN and the connection is secure. Use a torque wrench on the 3/4-inch pipe
plug installed on the front supply port to verify the valve is tightened to 59-148 lb-ft (80-200 Nm).
5.1.2 Mounted to Cross Member of Vehicle (Mounting Bracket Not Supplied)
Refer to Figure 5.
Fig. 5
ECU/DUAL MODULATOR VALVE MOUNTED
TO A CROSS MEMBER OFTHE VEHICLE WITH
CONTROL PORT FACING FRONT OF TRAILER
FRONT OF
TRAILER
ECU/DUAL MODULATOR VALVE MOUNTED WITH
CONTROL PORT FACING REAR OF TRAILER
FRONT OF
TRAILER
Exhaust
port
must face
DOWN.
Plug all unused
ports.
Exhaust
port
must face
DOWN.
Plug all
unused ports.
CONTROL
PORT
CONTROL
PORT
4014264a

11
Installation
When mounting the ECU/dual modulator valve assembly to the trailer cross member, refer to SAE
specification J447, Prevention of Corrosion of Motor Vehicle Body and Chassis Components. Follow all
recommendations and procedures. Your supervisor should have a copy of this specification.
1. Install a 3/4-inch NPT fitting in the supply port. Use a 3/4-inch NPT pipe plug to plug the unused
supply port (Port 1). Apply SAE-standard, DOT-approved sealing paste to either the first few threads
or over the whole length. Pipes with pre-applied thread sealant may also be used.
2. Locate a position for mounting the assembly to the vehicle cross member midway between the side
rails, close to the brake chambers the valve serves.
Drill two 3/8-inch mounting holes. The distance between the two holes (O.D.) must be
3-13/16-inches (97.2 mm) and mount directly to the cross member.
OR
Build a mounting bracket with two 3/8-inch mounting holes spaced 3-13/16-inches (97.2 mm) O.D.
apart.
3. Use two 3/8-inch Grade 8 bolts with prevailing torque nuts to attach the assembly. Tighten the bolts to
26 lb-ft (35 ± 3 Nm).
5.1.3 Attach the ABS External Relay Valve (4S/3M Systems Only)
The ABS external relay valve, part number 472 195 033 0, may be mounted on the air tank or on the cross
member of the vehicle.
5.1.4 Tank-Mounted
WARNING
You must use a Schedule 80 hex nipple (3/4-inch NPTF) to mount the ABS external relay valve
assembly securely to the air tank to avoid possible serious personal injury and damage to the
component.
1. Use a 3/4-inch NPTF Schedule 80 hex nipple to attach the relay valve assembly to a reinforced air
tank. Do not overtighten, potential damage to the valve could occur.
NOTICE
WABCO does not recommend the use of a vise when installing the hex nipple. Use of a vise may
cause overclamping. Overclamping may damage the internal components of the ECU/dual modulator
valve assembly.
2. Use a 3/4-inch NPTF pipe plug to plug the unused supply port. Apply SAE-standard, DOT-approved
sealing paste to either the first few threads or over the whole length. Pipes with pre-applied thread
sealant may also be used.

12
Installation
3. Rotate and tighten the relay valve assembly until the exhaust port faces down and the connection is
secure. Use a torque wrench or ratchet with an extension at the 3/4-inch pipe plug installed on the
front supply port. Figure 6.
Fig. 6
Exhaust
port must
face DOWN.
PLUG
UNUSED
PORTS
ABS EXTERNAL MODULATOR VALVE
CONTROL
PORT 4
SUPPLY
PORT 1
1002073d
5.1.5 Mounted to Cross Member of Vehicle (Mounting Bracket Not Supplied)
When mounting the relay valve assembly to the trailer cross member, refer to SAE specification J447,
Prevention of Corrosion of Motor Vehicle Body and Chassis Components. Follow all recommendations and
procedures.
1. Install a 3/4-inch NPTF fitting in the supply port. Use a 3/4-inch NPTF pipe plug to plug the unused
supply port (Port 1). Apply SAE-standard, DOT-approved sealing paste to either the first few threads
or over the whole length. Pipes with pre-applied thread sealant may also be used.
2. Install the valve with two locknuts and washers as required. Tighten the locknuts to 18 lb-ft
(24 Nm).
5.1.6 Connect the Air Lines
Before connecting the air lines, plumb the spring brake relay or emergency brake relay into the system as
usual.
If you are mounting on a bracket, connect the air supply line from the supply tank to the supply
Port 1. Plug the unused port.
Use 5/8-inch O.D. min. nylon tubing or heavy-walled Schedule 80 pipe nipple (3/4-inch NPTF) if
you are mounting directly to the supply tank.
1. Connect the air delivery lines to the ECU/dual modulator valve assembly Port 2. For 4S/3M
installations, connect the air delivery lines to Port 2 on the external relay valve (3/8-inch NPTF).
2. Connect the air delivery lines to the appropriate brake chambers (3/8-inch NPTF). Figure 16.
The valve portion of the ECU/dual modulator valve assembly contains two separate valves: one
dedicated to roadside wheel ends, the other dedicated to curbside wheel ends. Each valve has
three delivery ports.
The external relay valve is an axle control valve. It controls brake chambers on one or two axles.
It is important that delivery lines from Port 2 are plumbed as shown. Refer to Figure 12 through
Figure 18.
3. Connect the brake service (control) line to the ECU/dual modulator valve assembly Port 4 (3/8-inch
NPTF).

13
Installation
4. For 4S/3M installations, perform the following procedures.
Connect the brake service (control) line to the ECU/dual modulator valve assembly Port 4
(3/8-inch NPTF) and ABS external relay valve control Port 4 (3/8-inch NPTF).
Use an ABS relay valve connection cable to connect the ECU/dual modulator valve assembly with
the ABS external relay valve.
5. Plug any unused delivery ports.
5.1.7 Install the Sensor Extension Cables (ABS-prepped Axles)
Instructions for installing sensors on non-ABS-prepped axles are included in Appendix I.
1. Visually inspect the tooth wheel and sensor to ensure no damage occurred during shipping. Perform
any necessary repairs before starting any installation.
2. Connect the sensors and cables on the prepped axles to the sensor extension cables. Figure 7.
Ensure that each connection is secure.
Fig. 7
SENSOR
EXTENSION
CABLE
SENSOR
AND CABLE
4003567b
3. Route the sensor cable along the back side of the trailer axle to the ECU/dual modulator valve
assembly. Route the cable with the brake hose.
Do not overtighten the tie wraps on a cable. Overtightening can damage the cable. Do not tie wrap the
molded sensor plug. The sensor extension cable must follow the brake hose to the ECU/dual modulator
valve assembly to allow for axle jounce and rebound.
4. Secure the cables every eight inches (203 mm) with tie wraps or cable clips.
5. Remove the protective plugs from sensors E and F for a 4S system.
6. Plug the sensor extension cables into the ECU/dual modulator valve assembly. To secure push the
sensor extension connection in until the locking tab seats.
7. Bundle any excess cable in a “Z”-shaped loop. Figure 8.

14
Installation
Fig. 8
BUNDLE
EXCESS
CABLE
4003553a
8. Secure excess cable in the sub-frame of the vehicle or along the air hoses as appropriate. Excess
cable should not exceed two feet (0.61 meter).
Various cable lengths are available, see Appendix IV.
5.1.8 Install the Power Cable
1. Identify the type of cable to be installed. Figure 9.
ABS trailer industry-standard pigtail connector power cable
Blunt-cut power cable (not shown)
Fig. 9
POWER CABLE
4013985b
2. For industry-standard weather pack power cables, route the cable from the harness connector to the
ECU/dual modulator valve assembly and secure it to prevent damage.
For blunt-cut power cables, route the cable from the ECU/dual modulator valve assembly to a junction box
which interfaces with the seven-way connector at the front of the trailer.
Leave enough slack in the cable to compensate for flexing of the trailer and sub-frame.
3. Bundle any excess cable in a loop (bow tie) and secure it in the sub-frame of the trailer body to
prevent cable damage.
4. Pull the yellow locking tab OUT to allow the power cable to be plugged in. Figure 10.
Fig. 10
POWER CABLE
POWER
SUPPLY
POWER
4013986a
MATING
TRAILER
HARNESS
CONNECTOR END

15
Installation
5. Plug the power connector into the power supply port of the ECU/Modulator valve assembly.
6. Push the yellow locking tab IN to secure the connection. Note: If it will not push in, make sure the
power cable is fully seated. Once the locking clip is secured, install a cable tie to secure the cable to
the cable mounting bracket.
7. Fasten the power cable with a cable tie.
8. If you are installing the power cable only, go to Step 10.
9. If you are installing the diagnostic cable:
A. Install the diagnostic cable bracket so that the diagnostic plug is accessible. The normal
location is on the right front corner of the sub-frame, but will vary depending on the type of
trailer.
B. Pull the yellow locking tab OUT to allow the diagnostic cable to be plugged in.
C. Plug the diagnostic cable into the Subsystem Port of the ECU/modulator valve assembly.
D. Push the yellow locking tab IN to secure the connection. Note: If it will not push in make sure
the cable is fully seated.
E. Fasten the cable with a cable tie.
F. Route the diagnostic cable from the Subsystem Port on the ECU/dual modulator valve
assembly to the diagnostic cable bracket.
G. Correctly secure the cable in the sub-frame to prevent cable damage. Leave enough slack in
the cable to compensate for flexing of the trailer and sub-frame
H. Bundle excess cable in a loop (bow tie) and secure the cable in the sub-frame. Figure 10.
10.Install the ABS indicator lamp on the trailer. Refer to the the Federal Moter Vehicle Safety Standard
(FMVSS) 121 Regulation from NHTSA for the exact location of the indicator lamp. Use an approved
lamp with ABS etched on the lens (available from major trailer parts suppliers).
To ensure correct lamp operation, use an incandescent-type DOT-approved lamp or an LED with integral
load resistor.
If you are using the industry-standard connector cable and do not have access to the mating trailer
harness, mask the open connector to protect it from paint or grease.
11. Connect the power. Use the industry-standard connector cable or a blunt-cut power cable.
For industry-standard connector cables: Attach the power cable to the harness on the trailer.
For an optional blunt-cut power cable: Wire the cable and ABS indicator lamp to the seven-way
connector on the trailer according to the following diagram. Figure 11.
Fig. 11
ECU POWER CONNECTOR
GROUND
WHITE
BLUE
RED
GREEN AND WHITE
TRAILER ABS
INDICATOR LAMP
(CONSTANT POWER)
(STOP LAMP)
(GROUND)
Junction box not shown. 4013987a
41
86
5
7
2
3

16
Installation
Typical Trailer iABS Installations
Refer to Figure 12 through Figure 18 for typical trailer ABS installations.
WABCO recommends placing the sensors on the axle that will provide the most braking performance. This
is based on the way the suspension reacts during heavy braking applications. The trailer manufacturer can
help provide this information. The following Figures 12 through 18 are recommendations for many of the
standard trailers built in North America.
Fig. 12
POWERSUPPL
Y
ABSSENSORF
ABSSENSORD
GIO 1
SUBSYSTEM/
DIAGNOSTIC
3rd MODULATOR/GIO2
ABSSENSOR E
ABSSENSORC
POWERSUPPLY
ABS SENSORF
ABS SENSORD
GIO1
SUBSYSTEM/
DIAGNOSTIC
3rdMODULATOR/GIO2
ABS SENSOR E
ABS SENSOR C
NOTE: Spring brake
lines not shown.
SERVICE/CONTROL LINES
SENSOR CABLES
SERVICE BRAKE
SUPPLY AIR
NOTE: Spring brake
lines not shown.
4013983a
D
C
2S/2M VALVE MOUNTED WITH CONTROL PORT
FACING FRONT OF TRAILER — SIDE-TO-SIDE CONTROL
FRONT OF
TRAILER
2S/2M VALVE MOUNTED WITH CONTROL PORT
FACING REAR OF TRAILER — SIDE-TO-SIDE CONTROL
FRONT OF
TRAILER
C
D

17
Installation
Fig. 13
Typical Tandem Axle Trailer
D
C
C
F
F
E
E
D
Typical Tandem Axle Trailer
NOTE: Spring brake
lines not shown.
SERVICE/CONTROL LINES
SENSOR CABLES
SERVICE BRAKE
SUPPLY AIR
NOTE: Spring brake
lines not shown.
POWERSUPPL
Y
ABSSENSOR F
ABSSENSOR D
GIO1
SUBSYSTEM/
DIAGNOSTIC
3rdMODULATOR/GIO2
ABSSENSORE
ABSSENSOR C
4S/2M VALVE MOUNTED WITH CONTROL PORT FACING FRONT OF TRAILER — SIDE-TO-SIDE CONTROL
FRONT OF
TRAILER
FRONT OF
TRAILER
4S/2M VALVE MOUNTED WITH CONTROL PORT FACING REAR OF TRAILER — SIDE-TO-SIDE CONTROL
4013989a
POWERSUPPLY
ABS SENSORF
ABS SENSORD
GIO1
SUBSYSTEM/
DIAGNOSTIC
3rdMODULATOR/GIO2
ABS SENSOR E
ABS SENSOR C

18
Installation
Fig. 14
D
C
F
E
POWER SUPPLY
ABSSENSORF
ABSSENSORD
GIO 1
SUBSYSTEM/
DIAGNOSTIC
3rd MODULATOR/GIO2
ABSSENSORE
ABSSENSORC
POWERSUPPLY
ABS SENSORF
ABS SENSORD
GIO1
SUBSYSTEM/
DIAGNOSTIC
3rdMODULATOR/GIO2
ABS SENSOR E
ABS SENSOR C
4S/2M TYPICALTRI-AXLE — VALVE MOUNTED WITH CONTROL PORT
FACING FRONT OF TRAILER — SIDE-TO-SIDE CONTROL
FRONT OF
TRAILER
E
F
C
D
4S/2M TYPICAL TRI-AXLE — VALVE MOUNTED WITH CONTROL PORT
FACING REAR OF TRAILER — SIDE-TO-SIDE CONTROL
FRONT OF
TRAILER
NOTE: Spring brake
lines not shown.
SERVICE/CONTROL LINES
SENSOR CABLES
SERVICE BRAKE
SUPPLY AIR
NOTE: Spring brake
lines not shown.
4013990a

19
Installation
Fig. 15
SERVICE/CONTROL LINES
SENSOR CABLES
SERVICE BRAKE
SUPPLY AIR 4013991b

20
Installation
Fig. 16
POWER SUPPLY
ABS SENSOR F
ABS SENSOR D
GIO1
SUBSYSTEM/
DIAGNOSTIC
3rd MODULATOR/GIO2
ABS SENSORE
ABS SENSOR C
POWERSUPPLY
ABS SENSORF
ABS SENSORD
GIO1
SUBSYSTEM/
DIAGNOSTIC
3rdMODULATOR/GIO2
ABS SENSOR E
ABS SENSOR C
F
E
D
C
4S/3M TYPICAL TRI-AXLE WITH FRONT LIFT — VALVE MOUNTED
WITH CONTROL PORT FACING FRONT OFTRAILER
FRONT OF
TRAILER
4S/3M TYPICAL TRI-AXLE WITH FRONT LIFT — VALVE MOUNTED
WITH CONTROL PORT FACING REAR OFTRAILER
E
F
C
D
FRONT OF
TRAILER
NOTE: Spring brake
lines not shown.
SERVICE/CONTROL LINES
SENSOR CABLES
SERVICE BRAKE
SUPPLY AIR
NOTE: Spring brake
lines not shown.
4013992a