1994 FIAT PUNTO control system

9*2 Braking system
2.3a Release tho locking clip ...
1 General information
The braking system is of the vacuum servo-assisted. dual-circuit hydraulic type. The arrangement of Ihe hydraulic system is such that each circuit operates one front ond ono rear brake from a tandem master cylinder. Under normal circumstances, both circuits operate In unison However, in the event of hydraulic failure in one circuit, lull braking force will still be available at two diagonally-opposite wheels. All models covered in this manual are fitted with front disc brakes and rear drum brakes. The front disc brakes are aotuated by single-piston sliding lype calipers, which ensure lhat equal pressure is applied to each brake pad. The rear drum brakes incorporate leading and trailing shoes, which are actuated by twin-piston wheel cylinders. A self-adjust mechanism is incorporated, to automatically compensate for brako shoe wear. As the brake shoe linings wear, the footbrnke operation automatically operates the adjuster mechanism, which effectively lengthens the shoe strut and repositions the brake shoes, to remove the llning-to-drum clearance. The mechanical handbrake linkage operates the brake shoos via a lever attached to the trailing brake shoe.
2.3b ... and remove the pad wear indicator wiring and brake fluid line from the suspension strut Load sensitive proportioning valves operate on the rear brake hydraulic circuits, to prevent the possibility of the rear wheels locking before the front wheels under heavy braking. Note: When servicing any part of the system, work carefully and methodically; also observe scmpulous cleanliness when overhauling any part of the hydraulic sysiem. Always renew components (in axle sets, where applicable) if In doubt about their condition, and use only genuine Fiat replacement parts, or at least those of known good quality. Note the warnings given in Safety first and at relevant points in this Chapter concerning fhe dangers of asoestos dust and hydraulic fluid.
Models with anti-lock braking system (ABS) Available as an option on certain models, the anti-lock braking system prevents skidding which not only optimises stopping distances but allows full steering control to be maintained under maximum braking. By electronically monitoring the speed of each roadwheel in relation to the other wneete, Ihe system can detect when a wheel is about to lock-up, before control is actually lost. The brake fluid pressure applied to that wheel's brake caliper is then decreased and restored (or modulated) several times a second until control
£s
regained. The system components comprise an Electronic Control Unit (ECU), four wheel speed sensors, a hydraulic unit, brake lines and dashboard mounted warning lamps.
The hydraulic unit incorporates a tandem master cylinder, a valve block which modulates the pressure in the brake hydrauli: circuits during ABS operation, an accumulator which provides a supply of highly pressursed brake fluid, a hydraulic pump to charge Ihe accumulator and an integral electronic control unit (ECU). The four wheel sensors are mounted on the wheel hubs. The ECU uses the signals produced by the sensors to calculate Ihe rotational speed of each wheel, The ECU has a self-diagnostic capability and will inhibit the operation of the ABS il a fault is detected, lighting the dashboard mounted warning lamp. The braking system will then revert lo conventional. non-ABS operation. II the nature of the laull ie not immediately obvious upon inspection, the vehicle must be taken to a Fiat dealer, who will have the diagnostic equipment
required
lo interrogate the ABS ECU electronically and pin-point the problem
2 Front brake pads - & renewal S

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Warning: Renew BOTH sets ol front brake pads at the same
time
- NEVER renew the pads on
only
one wheel, as uneven braking may result

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Warning: Note that the dust created by wear of the pads
may
contain asbestos, which is a health hazard. Never blow It out with compressed air, and don't inhale any of
it.
An approved filtering mask should be worn when working on the brakes. DO NOT use petrol or petroleum-based solvents to clean brake parts; use proprietary braks cleaner or methylated spirit only. 1 Firmly apply the handbrake, then jack up the front of the car and support it securely
on
axle stands (see Jacking and vehicle supporti. Remove the front roadwheeis. 2 Wording on one side of the vehicle, puth the caliper piston into its bore by pulling the caliper outwards. If necessary, press the piston back into its bore using a large G-clamp or a piston retraction tool. Keep a careful eye on the level of brake llufd in Ihe I reservoir as you do this - ensure that the
level
I does not rise above the MAX marking. 3 Whore applicable, release the locking dp and remove the pad wear indicator
wiring end
brake fluid line from the bracket at Ihe
base of
the suspension strut (see illustrations).
Petrol models without ABS 4 Remove the locking clip and exlracl the lower guide pin from the caliper (see illustrations) 5 Pivot the caliper body upwards and support In position with a length of wire or a cabie-fc. Avoid straining the hydraulic hose.
2,4a Remove the locking clip ... 2.4b ... and extract the lower guide pin from the caliper (petrol models without ABS)

Suspension and steering 10*2
Torque wrench settings (continued) Nm ibt ft Rasr suspension Damper lower securing bolt 95 70 Damper upper securing bolt 60 44 Handbrake cable support bracket-to-trailing arm screws 15 11 Hub nut 280 207 Trailing arm securing bolt 150 111 Steering Ignition switch/steering column lock securing bolts 4 3 Steering column mounting bolts 55 41 Steering gear mounting bolts 70 52 Steering wheel nut' 50 37 Subframe-to-body bolts 110 81 Track-rod end to hub carrier 40 30 Unlversaijointclampbolts 20 15 Roadwheels Roadwheel bolts 85 63 * Use a new nut
1 General information
Front suspension The front suspension is independent, comprising transverse lower wishbones, coil spring-over-damper strut units and an anti-roll bar. The hub carriors are bolted to the base of the stmt units and are linked to the lower arms by means ot balliotnts. The entire front suspension assembly is mounted on a subframe, which is In turn botted to the vehicle body.
Rear suspension The rear suspension incorporates a torsion beam axle, trailing arms, coil springs and separate telescopic dampers. In addition, a rear anil-roll bar is fitted to certain models. The components form a discrete sub-assembly which can be unboiled from the underside of the vehicle separately or as a complete unit.
Steering The two-piece steering shaft runs in a tubular column assembly, which is bolted to a bracket mounted on the vehicles bulkhead. The shaft Is articulated at its lower end by means of a universal Joint, which is clamped to the steering shaft and the steering gear pinion by moans of clamp bolts. The steering gear is mounted on the engine compartment bulkhead, and is connected to the steering arms projecting rearwards from Ihe hub carriers. The track-rods are fitted with balljoints at their inner and outer ends, to allow for suspension movement, and are threaded to facilitate ad|ustment. Hydrauiically-assisted power steering ts fittod to some models. The hydraulic system is powered by a belt-driven servo pump, which is driven from the crankshaft pulley.
Certain models are fitted with an airbag system. Sensors built into the vehicle body are triggered in the event of a front end collision and prompt an Electronic Control Unll (ECU) to activate the airbag, mounted In the centre of the steering wheel and the facia. This reduces the risk of the front seat occupants striking the steering wheel, windscreen or facia during an accident.

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Warning: For safety reasons, owners are strongty advised to entrust to an authorised Flat dealer any work which involves disturbing the airbag system components. The airbag inflation devices contain explosive material and legislation exists to control their handling and storage, in addition, specialised test equipment Is needed to check that the airbag system Is fully operational following reassembly.
2 Front hub bearings -renewal *
Note: A balljoint separator tool, and a press or suitable alternative tools (see text) will be required for this operation. The bearing will be destroyed during the removal procedure.
Removal 1 Chock the rear wheels, apply the handbrake, then jack up the front of the vehicle and support on axle stands (see Jacking and vehicle support). Remove the appropriate roadwheel. 2 Remove the brake disc and caliper, with reference to Chapter 9. Note that the caliper body can remain bolted to its bracket: there is no need lo disconnect the brake fluid hose from the caliper. 3 With reference to Chapter 8. slacken and remove the driveshaft hub nut. 4 On models with ABS, unbolt the ABS wheel sensor, and remove the screw securing the
ABS sensor wiring to the hub carrier. Suspend the sensor away from the working ares, to avoid the possibility of damage. 5 With reference to Section 17, separate
th»
track-rod end from the hub carrier, using
a
suitable balljoint splitter. 6 Remove the two nuts from tho botts securing Ihe hub carrier to the base of th» suspension strut (refer to Section
3).
Withdrew the bolts and separate the top of hub earrtt from the strut. 7 Disconnect the outboard end of Ito driveshaft from the hub, as described durirg the driveshaft removal and refitting procedm in Chapter 8. Note: There is no naod fo disconnect the Inboard end of the
drivestett
from the transmission. Caution: Do not allow the end of tin driveshaft to hang down under its
own
weight, as this places strain on the
CV
joints; support the end of the shaft uskg wire or string. 8 Slacken and remove the nut and clamp bolt, then push the lower arm down anc separate the balljoint from the base of the tab carrier (see illustrations). 9 At this stage, it is recommended that
the bub
carrier be taken to a engineering workshop,
as
the hub and bearing should ideally be removed from the hub carrier using a hydraulic press
2.8a ... Slacken and remove the nut...

Suspension and steering 10*8
9.1 Prise the horn centre pad from the steering wheel hub unbolt the lower end of the damper from the trailing arm. 9 Lower the trailing arm gradually using a trolley jack, until the coil spring Is released from its lower seat on the trailing arm and its upper seat on the subframe. Make a note of the orientation of the coll spring, to aid correct refitting later. Refitting 10 Refitting is a reversal of removal, lighten the damper lower retaining bolt to the specified torque. Trailing arm Note: The rear stub axles are integral with the trailing arm assemblies and cannot be renewed separately. Removal 11 With reference to Chapter 9. carry out the following: a) Remove the brake drum, shoes and adjuster assembly. b) Unbolt the brake hose union from the
rear
of the wheel cylinder. c) Unbolt the brake pipe mounting bracket from the trailing arm. 12 Refer to Section 7 and remove The rear hub and beanng assembly. 13 With reference to the relevant sub-Section, unbolt the lower end of Ihe damper from the trailing arm. 14 Raise the trailing arm using a trolley jack so that the coll spring Is compressed, then slacken and withdraw the trailing arm front mounting bolL 15 With reference to the previous sub-Section, gradually lower the trailing arm using a trolley lack and remove the coll spring. 16 Allow Ihe trailing arm to hang down, then pull the leading edge of the arm down from its mounting bracket. Refitting 17 Refitting Is a reversal of removal. Tighten all suspension fixings to the specified torque settings, but delay this operation until the full weight vehicle is resting on the roadwheeis -this prevents the damper and trailing arm bushes from being strained. 18 On completion, bleed the brake hydraulic system and adjust the operation of the handbrake, with reference to Chapter 9.
9.2 Unplug the wiring from the centre pad at the connector(s)
9 Steering wheel - % removal and refitting ^
Note: This procedure does not apply to vehicles fitted with an airbag A Warning: For safety reasons, owners are strongly advisod to entrust to an authorised Fiat dealer any work which involves disturbing the airbeg system components. The airbag inflation devices contain explosive material and legislation exists to control their handling and storage. In addition, specialised test equipment Is needed to check thet the alrbag system Is fully operational following reassembly.
Removal 1 Ensure that the ignition is switched off, then prise the horn centre pad from the steering wheel hub. Use the blade of a screwdriver, padded with PVC tape to protect the steering wheel (see illustration) 2 Unplug the horn and (where applicable) radio/cassette control switch wiring from the centre pad at the connectors) (see illustration) 3 Turn the steering wheel to its centre position, so that the roadwheeis are pointing straight ahead. 4 Make alignment marks between the steering wheel and the end of the steering column shaft, to aid correct refitting later, 5 Relieve the staking and then slacken and remove tne steenng wheel securing nut (see
9.5 Slacken and remove the steering wheel securing nut Illustration). Discard the nut as a new item must used on refitting. 6 Lift the steering wheel off the column splines. If it is tight, tap il near the centre, usrg the palm of your hand, or twist it from
side to
side, whilst pulling upwards to release il ton the shaft splines. If the wheel is particular tight, a suitable puller should be used.
Refitting 7 Before commencing refitting, lightly eca. Ihe surfaces of the direction indicator cancelling mechanism with grease. 8 Refitting is a reversal of ren>oval.
bearing a
mind the following points: a) Use a new steering wheel
securing not
and tighten it to the specified
torque.
Ensure that its outer collar
Is adequate^
staked to the column shaft
using a
hammer and punch (see Illustrations). b) Ensure that the direction Indicator
swiith
is in the central (cancelled/off)
position,
otherv/ise the sivitch may be damaged X the wheel Is refitted. c) Align the marks made on the
wheel and
Ihe steering column shaft during removeI 9 Note that if necessary, the position of tf* steering wheel on the column shaft cant* | altered in order to centralise the wheel (enstn that the front roadwheeis aro pointing
In the
straight-ahead position), by moving the vMti the required number of splines on the
sfcafc
Fine adjustment can be carried out by adjusting the length of both track-rwa simultaneously, but this operation is best entrusted to a Rat dealer or tyre specialist
9.8a Fit a new steering wheet securing nut... 9.3b ... and stake it to the steering column shaft using o hammer and punch

11 *12 Bodywork and fittings
switch panel, then remove the panel from the facia (see illustration). Label tho wiring connector to aid refitting, then unplug It. 0 Work along the lower edge of Ihe facia and remove all the securing screws; there are three on the drivers side and three on the passenger side - one is concealed inside the glove compartment, behind a plastic cap. 10 Wilh reference to Chapter 12, remove the cover and open the main fuse box. Where applicable, unscrew the fixings that secure the electronic control unit to Its mounting bracket. Remove the facia mounting bolts located adjacent to the mounting bracket (see illustration). 11 Refer to Chapter 10 and unbolt the steering column from Its support bracket, allowing the column to rest in the footwell. There is no need to slacken the clamp bolt at Ihe base of the steering column to separate it from the steering gear. 12 With reference to Chapter 12, remove front right and left speaker grilles. Remove the two facis upper mounting screws ihat are now exposed. Similarly, prise open the plastic cover from centre of upper edge of the fada and remove the mounting screw behind. 13 Carefully pull whole facia moulding forward away from tho bulkhead slightly. Label all wiring connectors to aid correct refitting later, then unplug Ihem. Check that nothing remains connected between the facia and bulkhead then draw the facia moulding away and remove It from the vehicle.
20.8 Remove the bolt (arrowed) and detach the backrest from the mounting bracket
Refitting 14 Refit the facia by following the removal procedure in reverse, noting the following points: a) Reinstate all electrical connections according to (he labels made during removal and ensure that cables are secured in their clips, using the origins/ routing. b) Ensure thai all ventilation ducting locates correctly over the rear of the grilles before tightening the facia retaining screws. c) On completion, reconnect the battery negative cable and chock the operation of all controls, gauges and Instruments disturbed during the removal process, Including the ventilation/heating system.
20 Seats -removal and refitting JS:
Front seats
Removal

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Warning: On models with seat belt pre-tonsionors, entrust the work of seat removal to a Flat dealer. DQNOTattempt to remove the seat on vehicles so equipped. 1 The front seats frames are secured to the fioorpan by four bolts. Whero applicable, prise out the caps from the plastic trim panel lo expose the bolt heads. 2 Slide the seat towards the rear of the car to gain access to the two bolts at the front, Ihen slacken and withdraw them. 3 Slide Ihe seat fully forwards and remove the two rearmost bolls. 4 Ufl the seat out of the cabin area.
(arrowed) located adjacent to the control unit mounting bracket Refitting 5 Refil the seat by reversing the remove! procedure. Rear seat back rests
Removal 6 Using the hand straps, raise the seal cushion and lilt it fully forward. 7 The rear seat back rests are mounted or hinged brackets which aro boiled to Ihe fioorpan. To remove both back rests together, first remove the screws and detach the load space carpet panel. 8 Unbolt the back rest panel from the mounting brackets (see illustration). Refitting 9 Refit tho back rests by reversing Ihe removal procedure. Rear seat cushion
Removal 10 Using the hand straps, raise the seat cushion and tilt it fully forward. 11 Remove ihe screws Ihat secure Ihe hinged brackets to tho fioorpan. then lift out the cushion (see illustration}. Refitting 12 Refit the seat cushion by reversing Ihe removal procedure.
20.11 Remove the screws (arrowed) that secure the hinged brackets to the fioorpan

Body electrical systems 12*3
3.4 The auxiliary fusebox, located inside the glovebox behind a drop-down panel auxiliary fusebox, which is located inside the glovebox behind a drop-down panel (see Illustration). 5 A blown fuse can be recognised from its melted or broken wire (see illustration). 6 To remove a fuse, first ensure that the relevant circuit is switched off. 7 Using the plastic tool clipped to the main fusebox lid, pull the fuse from its location. 8 Spare fuses are provided in the main fusebox. 9 Before renewing a blown fuse, trace and rectify the cause, and always use a fuse of the correct rating (fuse ratings are specified on the inside of the fusebox cover flap). Never substitute a fuse of a higher rating, or make temporary repairs using wire or metal foil; more serious damage, or even fire, could result. 10 Note that the fuses are colour-coded as follows. Refer to the wiring diagrams for details of the fuse ratings used and the circuits protected. Colour Rating Orange 5A Red 10A Blue 15A Yellow 20A Clear or White 25A Green 30A 11 The radio/cassette player fuse is located In the rear of the unit, and can be accessed after removing the radio/cassette player -refer to Section 12for greater detail.
Relays 12 A relay is an electncally-operated switch, which Is used for the following reasons: 4 A relay can switch a heavy current remotely from the circuit in which the current is flowing, therefore allowing the use of lighter-gauge wiring and switch contacts.
b)
A relay can receive more than one control input, unlike a mechanical switch. c) A relay can have a timer function - for example, the intermittent wiper relay. 13 The main and optional equipment relays are located in the main and auxiliary toseboxes (see Fuses). A number of additional relays may be fitted, depending on model and specification. These are generally mounted
3.5 A blown fuse can be recognised from its melted or broken wire adjacent lo the component being controlled; e.g. the radiator cooling fan relay(s) are mounted on a bracket next the cooling fan itself. 14 The direction Indicator/hazard warning flasher unit is mounted on the underside of the steering column slalk switch unit. It can be accessed by removing the steering column lower shroud panel (see illustration). 15 If a circuit or system controlled by a relay develops a fault, and the relay is suspect, operate the system. If the relay is functioning, it should be possible to hear it click as it is energised, if this is Ihe case, the fault lies with the components or wiring of the system. If the relay is not being energised, then either the relay is not receiving a main supply or a switching voltage, or the relay itself is faulty. Testing is by the substitution of a known good unit, but be careful - while some relays are identical in appearance and in operation, others look similar but perform different functions. 16 To remove a relay, first ensure that the relevant circuit is switched off. The relay can then simply be pulled out from the socket, and pushed back into position.
4 Buibs (exterior lights) -renewal
General 1 Whenever a bulb is renewed, note the following points:
3.14 Removing the direction indlcator/ha2ard warning flasher unit
a) Ensure that the relevant electrical circuit is isolated before removing a bulb. If in doubt, disconnect the battery negative lead before starting work. b) Remember that, if the circuit has just been in use, the bulb may be extremely hot. c) A/ways check the bulb contacts and holder, ensuring that there is clean metal-to-metal contact between the bulb and its live contacts) and earth. Clean off
any
corrosion or dirt before fitting a nevt bulb. d) Wherever bayonet-type bulbs are fitted, ensure that the live contacts) bear firmly against the bulb contact. e) Always ensure that the new bulb is of the correct rating (see Specifications), and that it is completely clean before fitting it; this applies particularly to headlight/foglight bulbs (see following
0 Pay attention to the orientation when fitting multi-filament bulbs (e.g. combined tail/brake light bulbs) • incorrect fitting will cause the filaments to illuminate In the wrong sequence.
Headlight 2 Open the bonnet. Ensure that the headlights are turned off at the stalk switch. Models with single reflector 3 Pull the wiring plug from the rear of the bulb (see illustration). 4 Pull the rubber boot from the rear of the headlight unit (see Illustration).
4.3 Pull the wiring plug from the rear of the bulb 4.4 Pull the rubber boot from the rear of the headlight unit

Body electrical systems 12*9
3 Undo the mounting screws and lift out the speaker (see Illustration). Unplug the wiring at the connector. 4 Refitting is a reversal of removal,
Rear parcel shelf speakers 5 Working underneath the relevant parcel shetf support bracket, remove the securing screws and lower the loudspeaker from the support bracket. Unplug the wiring at the connector (see illustration). 6 Refitting is a reversal of removal.
11 Radio aerial - J^s removal and refitting ^
Removal 1 Carefully prise off the plastic cap. then remove the securing screws and withdraw the aerial from the roof. 2 Oraw the aerial co-axial cable through the roof aperture and disconnect it. If there is insufficient slack In the aerial cable, remove the courtesy light unit/overhead panel from the inside of the vehicle (as described earlier in this Chapter) to gain access to the cable connector,
Refitting 3 Refitting Is a reversal of removal, but ensure that seal between the aerial housing and the roof panel is in good condition.
12.2 Removing the radio/cassette unit using the special extraction tools
12.3 Disoonnect the wiring plugs from the rear of the unit. Note the bayonet fuse (arrowed) which is a push fit In the rear of the unit
10.3 Lift out the speaker and unplug the wiring at the connector
12 Radio/cassette player -removal and refitting ^
Removal Note: Once the battery has been disconnected, the radio/cassette unit cannot be re-activated until the appropriate security code has been entered. Do not remove the unit unless the appropriate code Is known. 1 Disconnect the battery negative terminal (refer to Disconnecting the battery in the Reference Section of this manual). 2 Insert the special extraction tools supplied with the vehicle into the holes on either side of the radio/cassette unit. Press them home until the Internal clips can be felt to release (see illustration). 3 Pull the unit forwards from the facia, then disconnect the wiring plugs and the aerial lead from the rear of the unit. Note the bayonet fuse, which is a push fit in the rear of the unit, (see illustration).
Refitting A Refitting is a reversal of removal, ensuring that the wiring Is routed freely behind the unit.
13 Speedometer drive cable - % removal and refitting Ss ^
Note: Later vehicles are fitted with an electronic transducer in place of the mechanical speedometer drive. This is mounted on the fransm/ss/on casing; refer to Chapter 7A, Section 3, for details.
Removal 1 Remove the instrument panel as described in Section 7. 2 Working in the engine compartment, unscrew the sleeve securing the cable end to gearbox, then pull the cable from gearbox. 3 Where applicable, release the cable from the brackets in the engine compartment bulkhead, then pull the cable through into the engine compartment. If necessary, pull the cable grommet from the bulkhead.
10.S Lower the loudspeaker from the support brackot and unplug tho wiring at the connector
Refitting 4 Refitting is a reversal of removal, bearing in mind the following points: a} Ensure that the bulkhead grommet is securely seated. b) Refit the instrument panel with reference to Section 7. c) Note that certain models have alignment marks on the cable outer for use when refitting. The marks should be aligned with the bulkhead bracket when the cable is correctly refitted and routed.
14 Switches -removal and refitting ^
Steering column stalk switches Note: On vehicles equipped with sfeezing wheel-mounted radio controls, the column stalk switch unit also incorporates the rotary contacts for the steering wheel switches. Removal 1 Disconnect the battery negative cable and position it away from the terminal. Turn the steering wheel so that the roadwheeis are pointing in the straight-ahead position. 2 Refer to Chapter 10 and remove the steering wheel from the column. 3 Remove the screws and lift off the upper and lower steering column shrouds. 4 Using an Allen key. slacken Ihe clamp ring at the rear of the switch unit (see illustration),
14.4 Using an Allen key, slacken the clamp ring at the rear of the switch unit