Audi Cabriolet 2002 User Manual

278

Service.

The Audi A4 Cabriolet Design and operation

For internal use only

Self Study Programme 278

In over nine years of Audi Cabriolet production, the predecessor model acquired itself the status of a "modern classic". The long-awaited new generation also has all the makings of a vehicle heading for stardom:

With a length of 4,57 metres and a width of 1,77 metres, this vehicle lends new expression to the classical elegance of the Audi Cabriolet whilst at the same time emphasising the sporty character of the make. The philosophy behind the new Audi A4 Cabriolet concept is to create the ideal allyear-round vehicle. A standard feature of the new Audi A4 Cabriolet is a fully automatic electrohydraulic convertible top with a heated glass rear window.

It goes without saying that the Audi Cabriolet convertible top offers outstanding thermal insulation to provide not only perfect winter protection but also ideal sound absorption.

At the touch of a switch in the centre console, the convertible top can be completely opened or closed in only 24 seconds. It can also be operated from outside by inserting the vehicle key in the driver's door lock.

Contents

Page

Body

Exploded view . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Portal gauge. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Vehicle safety. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Vibration damping. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Convertible top

Convertible top design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Opening convertible top . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Closing convertible top. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Variable convertible top compartment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Convenience opening and closing of automatic convertible top . . . . . . . . . . . . 21

Emergency actuation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Hydraulic system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Hydraulic pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Hydraulic cylinders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

3/2-way solenoid valve NV 090. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Hydraulic "opening" functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Hydraulic "closing" functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Electronic components. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Interior monitoring system

Megawave interior monitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Central locking system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

The Self Study Programme contains information on design features and functions.

The Self Study Programme is not intended as a Workshop Manual. Values given are only intended to help explain the subject matter and relate to the software version applicable when the SSP was compiled.

New

Attention Note

Use should always be made of the latest technical publications when performing maintenance and repair work.

Body

Exploded view of body

278_001

Body

Portal gauge

As is the case with the A4 Saloon, use is made for the A4 Cabriolet of the alignment bracket set VAS 6042 in combination with VAS 6042/1.

In addition to the familiar portal gauge VAS 5007, the alignment bracket accessory VAS 5007/12 is also required for the A4 Cabriolet.

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The following mounting points are set:

– Left/right convertible top latch at

windscreen frame – A-pillar – B-pillar striker plate mount – Left/right convertible top main bearing

support

Correct positioning of the mounting points on the body ensures ideal convertible top geometry.

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Body

Vehicle safety

One of the main aims when developing the new A4 Cabriolet was to match the acknowledged high standards of vehicle safety already achieved by the Audi A4. This involved the incorporation of a wide range of safety features in addition to body shell modifications specific to convertible models.

Full-size driver's and front

passenger's airbag

Head/thorax

side airbag

Safety steering column

and pedal cluster

Rollover bar

Double-walled back panel

Seat belts with belt tensioners and belt force limiters

Modified A-pillar structure

Rear seat cross member

Optimised sill panels

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Body

The rigidity of the A-pillars is a particularly important factor with regard to occupant safety in the event of vehicle rollover. Use has therefore been made in the A4 Cabriolet of high-strength tubular bracing in addition to optimising the entire A-pillar structure.

Thanks to optimisation of their cross sections and wall thicknesses in conjunction with the use of high-strength panels, the sills play an important part in increasing body rigidity and vehicle safety.

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The transverse rigidity of the vehicle and thus also safety in the event of side impact are enhanced by the additional high-strength tubular elements of the rear seat cross member.

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Following a serious accident (rollover as well as head-on, side and rear-end impact), the two rollover bars are actuated by the control unit and moved into safety position

Pre-tensioned spring

Solenoid-

operated switch

with actuation

mechanism

in a fraction of a second by releasing the pretensioned springs. This, together with the A-pillars, creates a safety zone for the vehicle occupants.

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The back panel between rear seat and convertible top compartment is reinforced and of double-wall design. This further improves the rigidity of the body.

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Body

Vibration damping

The new A4 Cabriolet combines sporty vehicle dynamics with outstanding vibration damping characteristics.

The rigid attachment of the front subframe, diagonal

bracing in the rear body structure and an extremely

robust sill panel linking the front and rear ends of the

vehicle all add to its overall strength.

Coordination of axle and mechanical unit vibration with the body ensures that mechanical unit and running gear mountings are ideally designed to provide vibration damping. A module cross member additionally connected to the body and precisely dimensioned steering column attachment ensure that steering wheel judder caused by the road surface is kept to a minimum.

All this in conjunction with the previously mentioned reinforcing measures for convertible models results in a spaceframe-type structure. The level of torsional rigidity is thus more than double that of the predecessor model.

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Convertible top

Convertible top design

Even at first glance it becomes apparent that the convertible top is designed to fulfill the most exacting demands of everyday driving and winter conditions. The convertible top fabric is made of particularly easy-care material and does not have to be treated with impregnating agent or the like. The structure of the convertible top takes the form of a triple layer of fabric on the outside, a 15 mm thick insulating mat and a separate inner headliner.

Convertible top

fabric with

integrated rear

window

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The fabric is mechanically attached by means

of fastening strips and sections to the front

end of the convertible top, as well as to roof

frame, bracing hoops and convertible top

frame.

This efficient fastening system (the

convertible top is latched, clipped, riveted

and bolted) guarantees ease of repair and

service work.

Aluminium

By its nature, this design ensures not only simple removal and installation, but also a high level of reliability and durability. The rear window is made of mineral glass suitable for heating.

Roof guide element 1

Steel

The highest standards are also set in terms of mechanical rigidity and perfect optical integration into the appearance of the vehicle as a whole.

By combining aluminium and steel, the design of the convertible top linkage represents an ideal compromise between extreme rigidity and a minimal weight of only approx. 30 kg. The aluminium fastening sections permit straightforward removal and installation of the individual convertible top components.

Convertible top compartment lid

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The convertible top fabric is zipped directly to the intermediate layer (insulating mat) and thus indirectly to the bracing hoops. This keeps the so-called ballooning effect to a minimum.

Bracing hoop 1

Front bracing hoop

Bracing hoop 2

All these items combine to ensure the harmonious integration of the roof line into the Cabriolet design throughout the entire speed range.

Bracing hoop 3

Bracing hoop 4

Bracing hoop 5

Roof guide

element 2

Main guide

element

Main support

Convertible top frame

Convertible top compartment lid latch

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Convertible top

Opening convertible top

Prerequisites:

– Vehicle stationary / speed < 5 km/h – Ignition on – Boot lid closed – Variable convertible top compartment

lowered

Pull and hold convertible top switch in centre console. If switch is released, movement ceases instantly (freezes) and all convertible top elements remain in their current position for 10 minutes.

For more information on convertible top compartment, refer to Pages 20 and 21.

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From this position, the convertible top can be moved again in any direction by renewed actuation of the switch. The stop mode is terminated after 10 minutes and the convertible top then folds down from its current position. The convertible top is not fully open until the warning lamp in the dash panel insert goes out and the side windows start to move.

Convertible top opening phases:

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The front end of the convertible top is released from the roof frame. Then the convertible top frame is raised and the front end lifted off. At the same time the heated rear window is switched off by way of the control unit.

The convertible top compartment lid is released and fully raised. The open convertible top lock at the front end closes again as the top moves.

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The convertible top is completely folded away in its compartment.

The convertible top compartment lid is closed and locked again. The boot lid locking function is cancelled again but the heated rear window remains deactivated.

Once the convertible top has been stowed the warning lamp in the dash panel insert goes out. Continuing to pull the convertible top switch then causes the side windows to return to fully raised position.

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Convertible top

Closing convertible top

Prerequisites:

– Vehicle stationary / speed < 5 km/h – Ignition on – Boot lid closed

Press and hold down convertible top switch in centre console. If switch is released, movement ceases instantly (freezes) and all convertible top elements remain in their current position.

From this position, the convertible top can be moved again in any direction by renewed actuation of the switch. The stop mode is terminated after 10 minutes and the convertible top then folds down from its current position. The convertible top is not fully closed until the warning lamp in the dash panel insert has gone out.

Convertible top closing phases:

All the above-mentioned prerequisites must be fulfilled. Actuation of the switch locks the boot lid and at the same time activates the warning lamp in the dash panel insert. All the side windows are then lowered to a defined position. Once the windows have been lowered, the convertible top compartment lid is released and fully raised.

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The convertible top is swivelled forwards out of its compartment and at the same time the lock at the front end of the convertible top opens.

The convertible top frame is completely raised. The compartment lid is then closed again and fully latched. The boot lid is then released.

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The convertible top is swivelled towards the roof frame with the open lock facing forwards.

The convertible top frame is lowered onto the compartment lid and at the same time the front end of the convertible top comes to rest on the roof frame. Once the convertible top is in position, the lock is actuated and the front end latched again.

Once the convertible top is closed, the heated rear window is reactivated and the warning lamp in the dash panel insert goes out. Continuing to press the convertible top switch then causes the side windows to return to fully raised position.

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Convertible top

Variable convertible top compartment

The open convertible top is completely folded away in its variable compartment. When the convertible top is closed, this compartment can be raised to increase the size of the luggage compartment. The variable compartment must have been fully lowered before the convertible top can be opened. The variable compartment cannot be raised with the convertible top open.

Variable convertible top compartment lowered Operating lever in position A

Variable convertible top compartment raised Operating lever in position B

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Lower

compart-

ment tray

A message appears on the dash panel insert display if an attempt is made to open the convertible top without having lowerered the variable compartment.

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