WABCO ECU220 Users Manual

Integrated Vehicle Tire
Pressure Monitoring

Vehicle tire pressure
monitoring system

System functions
System configuration
Instructions for installation
and diagnostics

1st. edition

815 000 452 3
8150004523

Revisions of this document are not set up.
New versions could be found in INFORM website
www.wabco-auto.com

Ó Copyright WABCO 2004

Vehicle Control Systems

An American Standard Company

8150003993

Changes are reserved
Version 001/04.03(en)

Wabcodruck 815 000 452 3

FCC Notice

This device consists of Wheelmodul 960 730 XXX X (SA4-WM730)
and Electronic Control Unit 446 220 XXX X (SA4-ECU220)

This device complies with Part 15 of the FCC Rules. Operation is
subject to the following two conditions:

(1) this device may not cause harmful interference, and

(2) this device must accept any interference received, including

interference that may cause undesired operation.

Changes or modifications not expressly approved by the party
responsible for the compliance could void the user's authority to
operate the equipment.

Contents

1. System functions 5

1.1 System structure 7

1.1.1 Example of installation in the bus 8

1.1.2 Example of installation in the trailer 8

2. Configuration 9

2.1 Components 10

2.1.1 Wheel module 10

2.1.2 Electronic control unit (ECU) 12

2.1.3 Display 13

2.2 Wiring 14

3. Installation instructions 17

3.1 General instructions 17

3.2 Overview 17

3.3 Additional mounting into vehicle/bus 18

3.3.1 Additional mounting into trailer 19

3.4 Inflation pressure 19

3.5 Installation of the control unit in vehicle 20

3.5.1 Installation of the wiring harness in vehicle 20

3.5.2 Installation of the wiring harness in trailer 22

4. Diagnostics 26

4.1 System configuration 26

4.2 Diagnostics structure 26

4.3 Instructions for use 27

4.3.1 Display instructi ons 27

4.4 Various information on display 27

4.4.1 Normal data 27

4.4.2 Pressure data 28

4.4.3 Error messages 29

4.4.4 Display reset 30

4.5 System error signalization 31

4.5.1 Interrupted connection to the wheel module 31

4.5.2 System failure 31

4.5.3 Interrupted connection between control unit and display 31

1

3

1. System functions

System functions

IVTM

1.

IVTMstands for Integrated Vehicle Tire Pressure

Monitoring. It is the tire pressure monitoring system,
which is installed in the vehicle. IVTM continuously
monitors the pressure in all tires. This monitoring is
performed by the pressure sensors in all tires, which
relays information to the display in the cab in and warns
driver about critical pressure drop. IVTM makes tr ansport
safer and more efficient, becau se mor e than 80 % of tire
damage could be recognized before serious damage
occurs, which requires repair. IVTM thus cuts down
operational costs, as continually maintained optimized
pressure in all tire s results in minimal fuel c onsumption
and extension of service life of tires.

Let us present some information:

Tire manufacturers estimate that total losses caus ed by

Main reasons for brakedowns at commercial vehicles are:

Service / information 3%

Structure 3%

Salvage operation 4%

Drive line 4%

Chassis 2%

improper maintenance of tires of commercial vehicles are
more than 10 millions of Euro in Germany. Lot of vehicle
users unfortunately tend to overlook this important factor
of operational costs. By selecting correct tires and proper
maintenance it is possible to save up to 2500.- €per
vehicle for one year. The unnecessary expanses are
further increased by widely spread carelessness of
driving with under-inflated tires. Tires with 20 % lower
pressure are no e xception in e veryday life. This under­inflation reduces service life of tires by 20 % and
unnecessarily incr eas es fu el co nsu mpt ion .

In order to minimize these costs WABCO company
designed new sy stem I VTM, which al so in crea ses t raffic
safety.

Operating
supplies 1%

Engine 36%

Brakes 4%

Electric 17%

The mileage of tyres significantly depends
on the tyre pressure...

tyre pressure
too low

tyre pressure
too high

Tire pressure

Source: Se rvice 24 GmbH & Co. KG

Tyres 26%

66000 brakedown missions

for trucks and busses in 1999

and fuel consumption also depends on the
tyre pressure.

Fuel consumption

tyre pressure
too low

tyre pressure
too high

Service life reduction

5

1.

IVTM

System functions

Checks of the car fleets show:

Every second tire is under-inflated by more than
10 %.

Using of new IVTM system increases profitability :

• reduced fuel consumption due to lower rolling
resistance

• smaller tire wear owing to lower deformation
losses => longer tire life cycle

• Saving costs of manual tire pressure check
(up to 30 minutes for one vehicle)

• spare tire is not needed due to low probability of
rupture
=> higher vehicle load.

tyre pressure too low

IVTM warns driver about sneak pressure drop
early, i.e. before the tire could burst.

IVTM enhances safety of passengers, driver, vehicle and
traffic :

• The driver may react to sneak pressure drop
early and prevent up to 85 % of tire bursts.

Which types of pressure monitoring are
available?

Permanent tire press ure monitoring durin g driving could
be performed in several ways:

– direct tire pressure measurement

permanent on-line pressure monitoring is possible.
Extremely precise and effective, very expensive.

– direct tire pressure measureme nt with limit value

monitoring

not so precise.

– indirect tire pressure measurement

moderately expansive, not nearly as precise and
reliable. The pressure is calculated from drive slip,
measured by ABS turning sensors.

WABCO IVTM uses direct pressure
measurement and in comparison with systems
using ABS presents these advantages:

1. pressure monitori ng during parking or before driving
start; diagnostics memory

2. able to distinguish uniform diffusion losses

• Additionally, properly maintained pressure in
tires ensures s afe driving properties of ve hicle
and short braking distance.

IVTM ensures travel efficiency:

• Prevents unnecessary delays and idle time.

• No backup vehicles/emergency actions needed

• Prevents loss of confidence from unsatisfied
customers and resulting drop of turnover.

records about tire pressure (rise)

Air pressure
in bar

3. fast detection of pres sur e d ro p, reac ti on t ime in order
of several seconds.

4. display of c urre nt ti re pres sure

5. higher precision

6. identification of leaking tire

7. measurement is not affecte d by driving on lo w qual ity
road

8. measurement is not affected by uneven vehicle
loading

VEHICLE
rear axle inside

TRAILER
3 axles

VEHICLE
front axle

The range of tire pressure oscillation for utility vehicles is far higher then for passenger car.

6

System functions

IVTM

1.

This requires using sophisticated evaluation algorithm,
instead of using simple identification of limit value.

Other requirements for tire pressure monitoring
systems of utility vehicles:

• exact wheel identification for vehicles with more
than 10 wheels or with double wheels

• high efficiency of wireless data transport

• pressure range 2 - 14 bars

1.1 System architecture

IVTM system
Vehicle

CAN bus

CAN bus or
HF wireless data transfer
from trailer control unit
to vehicle control unit

• Identification of tire pres sure fluctuation ba sed
on load and tire wear.
This function req uires complicated "eval uative
algorithm".

• Wheel modules must be m ounted flexible with
respect to different ty pes and locations of tire
valves on rims, different rim designs and
frequent wheel changes and mus t allow easy
exchange.

IVTM system

Trailer

Display:

« Standalone » or integrated

WABCO system is based on one el ectronic circuit 446
220 00x 0, so called control unit, which receives wireless
data transmitted by wheel modul es. Whe el modules 960
730 00x 0 are conn ected to the whee l valves by hoses .
Pressure informati on is processed by algorith ms stored
in control unit.

The information is sent through CAN bus to di splay unit
446 221 000 0. Di splay unit con sists of o ne disp lay, two
indicators, one buzzer and two buttons.

Warning massages of different levels are displayed;
indicator colour and type of audio signal shows
seriousness of the problem:

Control unit

Vehicle

Control unit

Trailer

• Red light and 1 minute long audio signal
indicates serious defect; the vehicle must be
stopped immediately (possible threat to lives
and vehicle).

• Yellow light and 10 min utes long audio signal
indicates smaller defec t; the vehicle shoul d be
slowed down and lower pressure adjusted.

Defects found by IVTM s ystem are stored in electronic
memory (EEPROM) for diagnostic purposes.

Wheel module

fro wheel

7

1.

1.1.1 Example of installation in the bus:

IVTM

System functions

wheel module

electronic control unit (ECU)

1.1.2 Example of installation in the trailer:

Driver display

Display

8

Control unit

Vehicle

Control unit

Trailer

wheel module

(one module per one tire)

2. Configuration

r

Configuration

IVTM

2.

In order to display tir e pressure and trailer warnings to
driver during driving it is in general case necessary to
install IVTM to both par ts of v ehicle, i.e . one control unit
to trailer and one unit to motor vehicle. Any vehicle
equipped with IVTM could be connected to any trailer
equipped with IVTM. Control unit of vehicle identifies
control unit of trailer automatically: Synchronization is
ensured through the break lights wiring, data are
transported wirelessly.

As trailers are usually not permanently powered, it is
possible that due to the frequency of wheel modules
transmission the tire pressure data for all the wheels
could be availabl e after up to 15 mi nutes after the drive
start.

In combination with WABCO-TCE (Trailer Central
Electronics) or EBS systems the information about the
pressure could be transmitted into control unit through
standardized bus connection CAN according to 11992.

Future vehicl es wi ll be able to display the d ata from CAN

System structure

bus on multifunction d isplay on the dashboard. If such
vehicles will not be ava ilable, data will be transfe rred to
the vehicle control IVTM unit wirelessly.

Certificates

Certificates for mounting and additional mounting of
IVTM are available, which significantly facilitate approval
of vehicle registr ati on pa pers . Ce rti ficat es ar e not part of
this booklet, how ever in case of need they cou ld be or­dered in WABCO or by Internet at www.wabco-auto.com
:

Ordering number 815 000 414 3 (D) / 815 000 415 3 (GB)
Contents: Expertise
TÜH ATC - TB 2002-108.00 and
Certificate part of TÜH ATC - TB 2003-023.00

Ordering number 815 000 441 3 (D)
Contents: Model verification 94/9/EG
CE 0032, TÜV03 ATEXxxxx
Aplication range

ex II 2G EEx ib IIC T4

IVTM display

CAN bus

Wireless connection

IVTM ECU

Trailer
vehicle

data transfer

wireless

IVTM ECU
Vehicle

Wheel
modules

IVTM display

CAN bus

IVTM ECU
Vehicle

TCE/
EBS

Wireless connection

IVTM ECU

Trailer

vehicle

connection to TCE or EBS,

wireless data transfer

Integrated display Integrated display

CAN

J1939

IVTM ECU
Vehicle

EBS

ISO 11992

IVTM ECU

Trailer

vehicle

connection to TCE,

data transfer by CAN bus

Central
computer

Wheel
modules

TCE
Trailer

Central
Electronics

CAN

IVTM ECU
Vehicle

IVTM ECU

Trailer

vehicle

connection to EBS,

data transfer by CAN bus

J1939

ISO 11992

Central
compute

EBS

9

2.

IVTM

Configuration

Possible vehicle configuration:

Motor vehicle

4 x 2 4 x 2 6 x 2 6 x 2 6 x 2 / 6 x 4 6 x 2 / 6 x 4 8 x 4

Super-Single with with Super-Single

Steering-/ Steering-/lifting axle

Loading axle Super-Single

Trailer vehicles

1-axle 2-axles 3-axles 1-axle 2-axles 3-axles

trailer vehicle trailer vehicle trailer vehicle trailer vehicle trailer vehicle trailer vehicle

with double with double with double

tires tires tires

2.1 Parts

2.1.1 Wheel module

Wheel module is cast in plastic enclosure and is
composed of:

• pressure sensor 2-14 bars

• electronic circuits for data procession

• electronic circuits for data transmission

• lithium-battery

• 24 bit identification code

Life cycle of the battery > is five years under normal
operating conditions .

Wheel module is mounted by the standard nuts from
outside to the shank to rim and is connected to valve.
Result is:

+ easy installation, tire dismounting is not necessary
+ high quality of wireless data transfer
+ Modules remain in their place even during tire

change, i.e. the s ystem does not have to be newly
setup.

The wheel module must not disrupt wheel balance;
therefore the cou nter wei ght is moun ted on the o pposi te
side.

Evaluation and data transfer is provided by 433 MHz
signal. If the pressure is constant, measur ed value s are
transmitted every 15 minutes, if the pressure is changing,
frequency of data transfers is faster.

10

Configuration

IVTM

2.

Special identification code of each wheel allows unique
assignment of modules to particular wheels. Possibility of
receptions of signals from another vehicle is excluded.

Installation instructions:

– Single tires (front axle, lifting axle,

trailer axle, Super-Single):

1 wheel module + 1 weight

– Double tires (rear axle):

Wheel module mounting on front and lifting
axle

For wheels 22.5 x 7.5 , 22.5 x 8.25, 22.5 x 9 10 holes,
pitch circle diameter 335 mm, ET 160

Wheel with protective nut circle:

L-Shape wheel module 960 730 001 0 with hose 960 730
056 4. Install counter weight on opposite side.

2 standard wheel modules for outer wheel.
Please do not use plastic valve extensions, as these
parts are not designed for permanent pressure load. Use
instead brass extensions (i.e. Alligator V 153-MS-R,
length 177 mm, type 332 903) or flexible valve extensions
with clamps.

Remark:

During hose installation ensure that wheel module
connection is not expos ed to exce ssive mechani cal lo ad
or excessive pressure.

Do not use excessive force when tightening cup nut of tire
inflation valve. Check connection seal with test spray.

Replace damaged O rings of wheel module conn ection:

4.47 x 1.78 EPDM 70

Wheel with axle cap:

Wheel module 960 73 0 001 0 with module 960 730 057

4. Counter weight 960 730 820 4 on opposite side.

Wheel module installation on rear axle with
double tires

For wheels 22.5 x 7.5 , 22.5 x 8.25, 22.5 x 9 10 holes,
pitch circle diameter 335 mm, ET 160

2 wheel modules 960 730 001 0
Hose for outer wheel: 960 730 054 4 (22.5 x 7.5,

22.5 x 8.25 und 22.5 x 9)
Hose for inner wheel: 960 730 055 4 (22.5 x 7.5)
respectively 960 730 058 4 (22.5 x 8.25 and 22.5 x 9)
Counter weight is not needed.

11

2.

IVTM

Configuration

Wheel module installation on axle
of trailer with single tires and Super-Single

For trailer wheels 22.5 x 11.75 ET 0 and 120; Super­Single wheels 22.5 x 11.75, 22.5 x 15, 22.5 x 17, 10 holes
pitch circle diameter 335 mm

ET 0

2.1.2 Electronic control unit (ECU)

Three different typ es of el ectroni c cont rol unit ( ECU) ar e
used:

1. Motor vehicle (truck) 446 220 000 0

2. Attached vehicle (trailer) 446 220 001 0

3. Attached vehicle with TCE
(trailer with TCE) 446 220 002 0

ET 120

Wheel module 960 730 001 0
Hose for trailer wheel 22.5 x 11.75 ET 0:
960 730 055 4

Hose for trailer wheel 22.5 x 11.75 ET 120:
960 730 053 4

Hose for Super-Single wheel 22.5 x 11.75 and

22.5 x 15: 960 730 055 4
Hose for Super-Single wheel 22.5 x 17: 960 730 052 4

Install counter weight 960 730 820 4 on opposite side.

Electronic units differ by HF signal structure and
connection to CAN bus (ID). Externally could be
recognized by type label.

Technical pa ra m e t ers

Operational temperature range: - 40°C to + 80°C
Storage temperature range: - 40°C to + 90°C

max +100°C for 2h
Voltage: 24V ± 8V DC
Protection: IP 69K DIN 40050/IEC 529
Torque: 15 Nm ± 10%

Electronic control unit is mounted in central part of vehicle
to chassis, so that perfect HF connectio n with all wheel
modules and connection between vehicle control unit and
trailer control unit is ensured. For control units
preferentially use mounting system 960 730 350 4.

Wireless connec tion is provided by aeria l inside control
unit housing, which guarantees pressure signal reception
from all wheels even for most difficult operating
conditions.

All changes from pre-programmed required values of tire
pressure are immediately recognized by comparison with
limit pressure values and pressure changes.

Incorrect values of tire pressures are displayed
immediately during start of the drive (if the unit is
permanently powered).

12

Configuration

IVTM

2.

The system may be extended up to 12 wheel modules for
one control unit.

Performance of the sy stem may be checked by i nternal
diagnostics memory.

2.1.3 Display

red indicator light

STOP

button

Manometer symbol

button

„?“

yellow indicator light

Turtle symbol

All necessary information of IVTM system is shown on
display. Connected to particular control unit by CAN bus.

These data are among others shown on the display:
– All tire pressur es could be disp layed by pressi ng the

button (Manometer). Manual tire pressure checks are
not necessary.

– The driver is informed by pilot lights and audio signals:

• Yellow light indicates s ligh t ly l ower pres su re or
sneaking pressure drop: In such case the
maximum speed of vehicle should be
decreased and the tire pressure should be
checked on first occasion.

• Red light indicates critical pressure drop:
The vehicle should be stopped immediately.

– Pressing button “?” displays additional information

about position of defect tire and current pressure.

DIN-Bajonett-

DIN bayonet

Stecker

plug (7 pin)

(7polig)

Adaptor in the

Zwischenstecker

vehicle

im Fahrzeug

external

außen innen

2354

6

CAN-H

CAN-H

1

CAN-L

CAN-L

3

ground

Masse

7

+ 24 V

+24 V

5

brake light

Bremslicht

ignition

Zündung

inside

Bremslicht (nur bei Anhängefahrzeug)

Elektr. Anschlüsse +24 V, Masse, Zündung

electrical connectors +24V, gnd, ignition

offene Enden

stripped ends

5A-Sicherung vorgeschrieben!

5A fuse required

Diagnosestecker

Diagnostic plug

Diagnostic cable

Diagnosekabel

446 300 348 0

4
5
7
1

SUB-D plug

SUB-D Stecker

diagnostic

Diagnose-

interface

interface

brake light (on trailers only)

5
4
2
1

13

2.

2.2 Cabling

IVTM

Configuration

Motor vehicle: Cable set 894 607 295 0

14

1

Configuration

Trailer: Cable set 449 674 051 0

IVTM

2.

1

15

2.

IVTM

Configuration

Trailer with TCE: Cable set 449 302 000 0

16

Installation instructions

3. Installation instructions

IVTM

3.

3.1 General instruct ions

These installation instructions ar e for experts, who have
knowledge about installation of electronic and electro­pneumatic equipment in vehicles.

It describes on examples mounting of IVTM equipment in
motor vehicle and trailer.

Respect general and special laws and regulations.
Further respect drawings in appendix and particular

technical parameters.

Warning: Work on insufficiently secured vehicle may
result in spontaneous movement of the vehicle.

Safety instructions

Respect valid regulations for work
safety and instructions of vehicle
manufacturer.

Before mounting make all necessary
safety precautions, for example secure
the car against spontaneous
movement.

Do not clean working clothes,
workplace and tools by pressure air.

Wheel nuts must be tightened with
torque specified by vehicle
manufacturer. Check tightness of
wheel nuts after 500 km.

3.2 Overview

Additional mounting in motor vehicle/bus.

1. Wheel modules are installed first.

2. Installation of the control unit to vehicle chassis.

3. Display installation.

4. Mounting and connection of cable harness to the
control unit and display.

5. Finally: IVTM system configuration
with PC diagnostics.

Additional mounting in trailer

1. Wheel modules are installed first.

2. Installation of the control unit to vehicle chassis.
On three axles trailer preferentially in front of
the first axle

Display

Elektronik

control unit

(ECU)

(ECU)

Pin 15, 30, 31

Diagnose-

Kl. 15, 30, 31

steckdose

Brem slicht

1 wheel module

1 Rad modu l

per tyre

pro Reifen

diagnostic

socket

brake light

17

3.

3. Mounting and connection of cable harness to the
control unit.

4. Finally: IVTM system confi gur ati on
with PC diagnostics.

IVTM

Installation instructions

3.3 Additional mounting in motor vehicle/

bus

Wheel modules are installed first.

For the front wheels

always one module with
connecting hose and
counter weight is
necessary.
The vehicle needs not to
be lifted as only four wheel
nuts are dismounted.

brake

+24V

GND

Bremslicht

Elektronik

control unit

(ECU)

(ECU)

light

diagnostic

Diagnose-

socket

steckdose

First connect module h ose to w heel module b y insertin g
connecting segment to wheel module opening. Secure
the connection by tu rning the conn ecting se gment. After
mounting to wheel it could not be removed.

Unscrew four nuts and
remove protecting ring.
Then mount the wheel
module and counter weight
on opposite side.

Return protection ring and
tighten wheel nuts.
Connect hose to tire valve.

For installation to rear axl e of vehi cle (in th is exa mple)
two modules for double tires for each side with one
connecting hose are needed.

Warning:

Do not use plastic valve
extension

Requirements of this
connection are fulfilled only
by metal valve extension!

First remove four wheel
nuts depending on
mounting position of
module (on opposite sides)
as well.

18

Installation instructions

IVTM

3.

Connect hoses to m odules
and mount modules on
prepared location (removed
nuts). Then mount back
wheel nuts.

Connect hoses to valves.

3.3.1 Additional mounting in trailer.

For additional mounting in trailer follow installation
instructions for motor vehicle/bus. Pr oceed accordin g to
the same instructions.

In accordance with
mounting instructions for
vehicle, fir st co nne ct pr op e r
hose to the module. Further
in accordance with
mounting instructions for
motor vehicle, in case of
single front vehicle tires
install counter weight.

After removing of four nuts
install both parts an d return
back the nuts.

3.4 Inflation pressure

Actual tire pressures and pressures stored in diagnostics
should correspond with values given by vehicle or tire
manufacturer.

Inflation pressure in tires should ideally be set up in
ambient drive temperature, i.e. strictly before drive on
”cold” tires. In this mann er you will be operating your
tires with optimum inflation pressure and achieve
optimum life cycle with minimum fuel consumption.

It is common that for example during longer drive on
highway the tires are heated and their pressure rises.
Such higher pressure should under no circumstances be
lowered to standard value. Inflation pressure of ”cold”
tires would then be significantly lower.

In following situati ons the inflation pressure set on cold
tires is not correct:

1. Inflation pressure was adjus ted in very c old night an d
during drive in day the tires are heating up. In this case
the tire pressure during day is too high.

Example:

Required inflation pressure: 8 bars
Ambient temperature
during tire inflation: -10°C
Ambient temperature
during day drive: +20°C

☞ Effective tire pressure during day

rises above 9 bars.

☞ Inflation pressure during could night shoul d therefore

be 7.1 bar.
The tire pressure before day drive would in this
example be
8 bars.

2. Inflation pressure in cold weather is adjusted in
heated workshop. In this example the tire inflation
pressure is too low during drive.

Finally connect hoses to tire
valves.

Example:

Required inflation pressure: 8 bars
Ambient temperature
during tire inflation: +20°C
Ambient temperature during drive: -10°C

☞ Effective tire pressure drops to

approximately 7.1 bar.

☞ Inflation pressure for heated workshop should be set

to 9 bars.
Tire pressure would reach correct values outside
before the start of the drive.
8 bars.

19

3.

IVTM

Installation instructions

3.5 Installation of electronic control unit
to motor ve hicle

The control unit should be installed on such place, which
is in same distance fr om all wheels. It is usually instal le d
in the centre of vehicle. Fo r trailer the cont ro l unit sh oul d
be installed ahead of front axle.

Control unit

Install electronic control unit in such position, that
longitudinal axis of unit is parallel with longitudinal axis of
vehicle. Apart fro m that on ly inst allatio n ”ter minals up” is
allowed. This mounting position is necessary for optimum
reception of signal.

Use body shell clams for mounting of control unit 960 730
350 4, because welding is not allowed on chassis of
vehicle.

Body shell clamp

3.5.1 Cable harness installation

Motor vehicle

For installatio n of electroni c units into m otor vehicle use
prepared cable harnesses WABCO. IVTM parts are
connected by installed plug-in modules. Adjust location of
cables to individual vehicle situation. Respect relevant
law regulations.

Connection to
brake lights

wire from
IVTM-ECU

Wire to
brake light

Diagnostics plug

connecting

wiring-plug

Connection to
terminals 15, 30 and 31

Connection to battery (permanent, plus) and ignition
must be fused 5A.

Example of motor vehicle wiring with
connectors to brake lig hts, plus terminal of
Batt, chassis and ignition.

20

Installation instructions

IVTM

3.

Display

Chassis

Connection to

IVTM-ECU

Break lights wiring should be connec ted only in case of
vehicles with trailers, i.e. for example not for buses.
Connection provides synchronisation of signals from
trailer to motor vehicle.

Driver cabin

WABCO

Diagnostics

Diagnostics

Diagnostics-

Plug

red: +24
grey: ignition (with fuse 5A!)
blue: ground

Install display on fa vo ur abl e positi on on dashboard. Due
to audio signals it is not necessary to install display
directly in front of driver.

.

Wire

446 300 348 0

connection
for PC: COM

yellow: brake light

Interface

446 301 021 0

Break lights cable could be connected for example
through the connector for brake pedal. Conditions of
particular vehicle may and must be taken into account.

21

3.

IVTM

Installation instructions

If possible install IVTM diagnostics plug close to other
diagnostics terminals of vehicle.

3.5.2 Cable harness installation
Trailer

For installatio n of electroni c units int o motor veh icle use
prepared cable harnesses WABCO. IVTM parts are
connected by installed plug-in modules. Adjust location of
cables to individual vehicle situation. Respect relevant
law regulations.

Wiring + 24V must be fused 5A.

22

Install electronic control unit in such position, that
longitudinal axis of unit is parallel with longitudinal axis of
vehicle. Apart from t hat only inst allati on ”te rmina ls up ” is
allowed. This mounting position is necessary for optimum
reception of signal.

Use body shell clams for mounting of control unit 960 730
350 4, because welding is not allowed on chassis of
vehicle.

Installation instructions

Examples of Vario C wiring:

Vario C wiring

without additional

electronics

+ 24 Volt

Masse

IVTM

**)

3.

For connection in Vario C housing
are needed auxiliary thread
connections :

Vario C wiring

with auxiliary electronics

ECAS

with power module

446 107 530 0

brake light

**)

+ 24 Volt

Masse

brake light

**) Remark:

For installation of c onnecting cable IVTM in trailer
WABCO is recommending cable socket AK 192
from:
Apparatebau Kirchheim-Teck GmbH & Co.
Alleenstraße 36
D 73230 Kirchheim-Teck

23

3.

Necessary

Necessary

IVTM

4x2

Super Single

Parts

Trailer

for 2 axles

Parts

trailer

for 3 axles

ET 120 ET 0 ET 120 ET 0 truck bus

Installation instructions

Necessary

Necessary

Necessary

Super

Single

Parts

for 6x2-

Swivel bus

parts

for 6x2-

parts

for 4x2-

double

tires

truck bus truck bus

960 730 054 4 2 2 2 2 4

960 730 058 4 2 2

960 730 055 4 2 2 4 4 6 4 2

24

Prototypes Series

Situation in the beginning of 2003

Truck ECU 884 906 939 0 446 220 000 0 1 1 1 1 1 1 1 1

Trailer ECU 884 906 940 0 446 220 001 0 1 1 1

Display 884 650 161 0 446 221 000 0 1 1 1 1 1 1 1 1

Truck cable 894 607 295 0 1 1 1 1 1 1 1

Trailer cable 449 674 051 0 1 1 1 1

884 623 605 0 960 730 001 0 4 4 4 4 8 4 6 6 4 4 2 2

wheel module

Standard

wheel module

884 014 985 0 960 730 007 0 2 2 4 4 2 2 2 2

L-Shape (front axle)

Counter weight 960 730 820 4 2 2 4 4 2 6 6 6 4 4 4 4

L-shape hose 960 730 056 4 2 2 4 4 2 2 2 2

External hose for rear

axle

axle

Internal hose for rear

Single tire hose 960 730 052 4 2

ET 120 trailer hose 960 730 053 4 6 4

ET 0 trailer hose external

hose for bus rear axle

Super Single for bus

Installation instructions

Review of connecting hoses:

Super Single 22.5 x 17 960 730 052 4

Trailer 22.5 x 11.75 ET 120 960 730 053 4

IVTM

3.

Double tires – external 22.5 x 7.5 ET 160

22.5 x 8.25 ET 160

22.5 x 9 ET 160

Trailer 22.5 x 11.75 ET 0
Double tires – internal 22.5 x 7.5 ET 160

Super Single 22.5 x 11.75

22.5 x 15

Independent L-shape wheel 22.5 x 7.5
with protecting ring 22.5 x 8.25 ET 160

22.5 x 9

Independent wheel 22.5 x 7.5
with axle cap 22.5 x 8.25 ET 160

22.5 x 9

960 730 054 4

960 730 055 4

960 730 056 4

960 730 057 4

Double tires – internal 22.5 x 8.25 ET 160

22.5 x 9

960 730 058 4

25

4.

IVTM

Diagnostics

4. Diagnostics

4.1 System configuration

Newly installed IVTM system is configured, i.e. set up, by
PC diagnostics of IVTM system.
Parts necessary for configuration:

Diagnostics connecting cable: 446 300 348 0

Diagnostics interface with cable: 446 301 021 0

Diagnostics software: 446 301 730 0

Remark: Diagnostic could be do ne only with special diagnostics cabl e for IVTM, other diagnos tics cables
WABCO (i.e. cables for EBS, ECAS etc.) could not be used.

4.2 Diagnostic structure

26

Diagnostics

IVTM

4.

4.3 OPERATING INSTRUCTIONS

The system consists of one electronic unit, so called
electronic control unit, which receives wireless
information from wheel modules. Wheel modules are
permanently connected by hoses to tire valves. Pressure
information is proc essed by algorithms stored in control
unit.

Data are relayed by CAN bus to display. Display unit
consists of one d isplay, two indicators, one buzzer and
two buttons.

Warnings of different levels are signalised; importance
could be recognised by colour of indicator light and audio
signal:

– Red light (STOP) and 1 minute long audio signal

indicates serious de fect; th e v ehi cl e m us t be st opp ed
immediately (possible threat to lives and vehicle).

– Yellow light (turt le) and 10 m inutes lon g audio signa l

indicates smaller defect; the vehicle should be slowed
down and lower pressure adjusted.

If the tire pressur es are not exceed ing specifie d values,
following data are displayed after initialisation:

Two buttons on fro nt panel are used to control different
functions.

Left button with symbol of manomet er displays vehi cle
tire pressure.

Right button with question mark symbol shows detected
defects. If pressed longer, the error messages are
deleted (after correction of tire pressure).

Defects found by IV TM are stored i n electronic memo ry
for diagnostic purposes.

4.3.1 Display operation

Cable harness is connected to display by 4 -pole plug. It
is powered only if the ignition is on.

After the ignition is switched on, internal check procedure
is performed, when all internal functions are tested: all
symbols are displayed for one second, all pilot lights and
audio signals are switched on; this procedure is repeated
twice.

psi
bar

IVTM

+

psi
bar

h
mn
km
psi
bar

4.4 DIFFERENT VALUES ON DISPLAY

4.4.1. Normal values

After initialisation the top view of vehicle is displayed
(driving directi on upward) for 12 seconds. For example
4x2 truck is shown like:

IVTM

Fig. 3

If the trailer with IVTM system is connected to motor
vehicle, both vehicles are shown alternatively in one
second intervals for 12 seconds.

Fig. 1

27

4.

IVTM

Diagnostics

Example: If the three axles trailer is connected to shown

vehicle, Fig. 3 is changed to:

IVTM

Fig. 4

The display shows IVTM logo (Fig. 2) and stays without
change till the button is pressed or the defect is found.

If the defect is found on one of the vehicle wheels, symbol
of particular wheel is blinking in corresponding image
(vehicle or trailer). Depending on seriousness of defect,
control lights and audio signals are switched on.

If the defect is found on more than one wheel of vehicle
or trailer, symbols of all defect wheels are blinking.

4.4.2 Pressure display

This manometer function shows the tire pressures
measured by IVTM system, and completely replaces
manual pressure measurement through tire valves.

The values are displayed after pressing left button
”manometer” in normal mode.

The axle, whose pressures are displayed, is marked.

bar bar

IVTM

Fig. 7

Tire pressures on following axle could be displayed by
repeatedly pressing button ”manometer”.

If one of the axles is equipped with double tires, individual
pressures are displayed in sequence.

IVTM

Fig. 5

If the defects are found in both vehicle and trailer wheels,
images of both vehicles are changing each ten seconds,
and all defect wheels are blinking.

IVTM

Fig. 6

In all cases the indicator light and audio signal
corresponding with the worst defect is switched on.

If the defect is found on one tire of double tires, the
system activates error message for both tires.

Display of pressure in outer tires of double tires:

bar bar

IVTM

Fig. 8

The pressure of inner tires could be displayed by
repeatedly pressing button ”manometer”:

bar

bar

IVTM

Fig. 9

If the trailer is connected the pressure in the tires of trailer
is displayed in the same way.

28

After display of tire pressure in last axle and pressing the
button ”manometer” the display switches to normal
mode.

1

Diagnostics

IVTM

4.

If the button ”manometer” is not pressed for 20 seconds,
the display also switches to normal display mode.

4.4.3 Error messages

All defects found by system could be displayed in order of
their importance.

This function could be activated by pressing button
”question mark - ?”.

Symbol of defect wheel blinks in particular vehicle image
(both tires in case of double tires), symbol of detected
defect and particular indicator are lighted.

By successive pressing the button ”?” it is possible to
display all defects. After another press of button the user
is asked to reset data (see 4.4.2).

If button ”pump” is not pressed for 20 seconds, display
switches to normal mode.

If no defect is found the system does not react to pressing
button ”?”.

Different types of defects, which could be found by IVTM
system, are described below. Let us start with the most
dangerous.

4.4.3.2 Extremely high pressure

bar

IVTM

Fig. 11

Display informs about position and current pressure of
defect tire. Yellow indicator is on.

Action:

Driver should slow down the vehicle to prevent bursting
of tire. The cause of high pressure should be found out
(for example heated brake).

4.4.3.3 Sneaking pressure drop

bar

IVTM

4.4.3.1 Extremely low pressure

bar

IVTM

Fig. 10

Display informs about position and current pressure of
defect tire. The symbols of wrench and red light are
displayed.

Action:

Drive should immediately stop the vehicle and check the
pressure drop. Generally, it is necessary to change the
tire because of the damage.

Fig. 12

Display informs about position and current pressure of
tire, where the drop was detected. The symbols of
wrench and soft tire are displayed. Yellow indicator is on.

Action:

Driver should slow down the vehicle and on first occasion
find out the cause of pressure drop, or change the tire.

4.4.3.4 Low pressure

bar

IVTM

Fig. 13

Display informs about position and current pressure of
defect tire. Symbol ”pump” is displayed. Yellow indicator
is on.

29

4.

IVTM

Diagnostics

Action:

Drive should slow down the vehicle and on first occasion
adjust the tire pressure.

4.4.3.5 High pressure

bar

IVTM

Fig. 14

This defect could be found only for cold tires, i.e. if the
vehicle stand for more than four hours with ignition
switched off.

In this case the defect is displayed two minutes after the
ignition is switched on.

Display informs about position and current pressure of
defect tire. Symbol ”pump” is displayed. Yellow indicator
is on.

If the image of vehicle is displayed and you press the
button ”pump” for 5 seconds, the control unit of this
vehicle is reset.

Switching off of the display confirms successful reset.

If the unit is not reset, the display changes to normal
operating mode.

As all data about defects and tire pressures of particular
vehicle are deleted, new information about tire pressure
may be displayed after up to 15 minutes.

4.5 SYSTEM ERROR DISPLAY

4.5.1 Connection of the wheel module is

interrupted

Action:

The pressure in tires should be adjusted before starting
the engine.

4.4.4 Reset

This function allows resetting all information about tire
pressure and possible defects of IVTM system.

Reset is necessary for example after adjustment of the
tire pressure, because otherwise the system may report
false defect. Repeatedly press right button ”?”, until all
defects of vehicle are displayed. All wheels are lighted.
This image of vehicle is displayed for five seconds. After
that, if IVTM system recognizes trailer, it displays image
of trailer for another five seconds.

IVTM

Fig. 16

This error message is shown when there are no data
received from one of the wheel modules for more than
one hour.

Display shows position of wheel, which is not transmitting
data. Two lines are displayed instead of pressure value.
IVTM logo is crossed.

Action:

– Optimize mounting position of control unit

– ECU and/or wheel module is excessively dirty

If this error shows after several years of operation of
wheel module, it is likely, that the module battery is
discharged. Change the wheel module (it is necessary to
perform new setup
using system diagnostics).

30

Diagnostics

IVTM

4.

4.5.2 System error

IVTM

Fig. 17

This error message is displayed when IVTM functions or
regular tire pressure monitoring fails.

All wheels are blinking on display. IVTM logo is crossed.

In certain cases the type of vehicle equipped with IVTM is
not recognized. In this case following data are displayed:

IVTM

4.5.3 Interrupted connection between control
unit and display

If the connection between IVTM and display is
interrupted, following information is shown and white line
on IVTM logo is flashing.

IVTM

Fig. 19

Action:

– Check plugs: ECU,

connecting plug

– Check connection to harness 30

– Plugs from harnesses 15 and 30 could have been

interchanged
(display is on even after ignition is switched off)

Action:

System diagnostics, check of the control unit wiring

Fig. 18

– Check cable connections

– Diagnostics

31