1996 FIAT PUNTO Valve

4D*2 Exhaust and emission control systems
2.2 Charcoal canister location behind tho right-hand headlight
conditions, via a plunger valve, The system is controlled electronically by means of an emissions system control unit. Evaporative emission control • petrol models To minimise the escape of unburned hydrocarbons Into the atmosphere, an evaporallve loss emission control system is fitted to petrol models, The fuel tank filler cap Is sealed and a charcoal canister is mounted underneath the right-hand headlamp to collect the petrol vapours released from the fuel contained In the fuel tank. It stores them until they can be drawn from the canister (under the control of the fuel Injection/ignition system ECU) via the purge valve into the Inlet tract, where they are then burned by the engine during normal combustion. To ensure thai the engine runs correctly when it is cold and/or idling and to protect the catalytic converter from the effects of an over-rich mixture, the purge control valve is not opened by the ECU until the engine has warmed up, and the engine is under load; the valve solenoid is then modulated on and off to allow the stored vapour to pass into the inlet tract.
Exhaust systems The exhaust system comprises the exhaust manifold, an exhaust downpipe, • catalytic convorter, an intermediate pipe with silencer, and a tailpipe with silencer, On turbo diesel models the turbocharger is fitted between ihe exhaust manifold and the downpipe.
5.5a On 16-valve engines, undo the bolts and remove the manifold heat shield...
2 Evaporative loss emission ^ control system - information and component renewal ^
Information 1 The evaporative loss omission control system consists of the control solenoid (or purge valve), the activated charcoal filter canister and a series of connecting vacuum hoses. 2 The control solenoid and charcoal canister are both mounted on the right-hand side of the engine compartment behind the headlight (see illustration).
Component renewal
Control solenoid 3 With the bonnet open, disconnect the hoses from the control solenoid on the top of the charcoal canister. 4 Disconnect the wiring and remove the solenoid. 5 Refitting is a reversal of removal. Charcoal canister 6 Remove Ihe control solenoid as desenbed previously. 7 Disconnect Ihe fuel tonk hose from the canister 8 Detach the mounting and remove the canister. 9 Refitting Is a reversal of removal. Multifunction valve 10 The multifunction valve >s mounted on top of the luel tank. Removal and refitting is similar to that described for the tank sender gauge/pump (refer to Chapter 4A or 4B).
3 Crankcase emission system - general information
The crankcase emission control system consists of a hose from the camshaft cover to the air cloanor with a branch to Ihe throttle body. The main hose Incorporates a flame trap and the Inlet to the throttle body incorporates a calibrated hole.
5.5b ... then remove the bracket
The system requires no attention other than to check at regular intervals that tho hoses are free of blockages and undamaged.
4 Lambda oxygen sensor -removal and refitting &
Note: 7?5e Lambda oxygen sensor is doiicata and will not work if it is dropped or knocked, it its power supply is disrupted, or if any cleaning materials are used on it.
Removal 1 The sensor Is threaded Into the exhaust front downpipe. Access if best gained Irom underneath the vehicle. Apply the handbrake then )ack up the front of the vehicle and support on axle stands (see Jacking and vehicle support). 2 Disconnect the sensor wiring connector located on the front of the engine. 3 Working beneath the vehicle, unscrew the sensor, taking care to avoid damaging the sensor probe as it Is removed- Note: As a flying lead remains connected to the sensor after it has been disconnected, if the correct spanner is not available, a slotted socket
will
be required to remove the sensor.
Refitting A Apply a little anti-selze grease to (he sensor threads • avoid contaminating the probe tip. 5 Refit the sensor to the downpipe. tightening it to the correct torque. Reconnect the wiring. 6 Lower the vohicle to the ground.
5 Exhaust manifold - % removal and refitting jk
Petrol models
Removal 1 On 1242 cc (16-valve) engines, remove tho air cleaner and inlet system components as described in Chapter 48. 2 Firmly apply the handbrake, then jock up the front of the car and support It securely on axle stands (see Jacking and vehicle support). 3 Disconnect the oxygen sensor wiring or alternatively romovo Ihe sensor completely. 4 Unscrew the nuts and disconnect the exhaust downpipo from Ihe exhaust manifold flange. Recover the gasket. 5 On 1242 cc (16-valve) engines, undo the bolts and remove the manifold heat shield, then remove the bracket at the timing belt end of the manifold (seo Illustrations). 6 Unscrew the mounting nuts, remove the washers, and recover any additional brackets fitted over the studs, noting their locations. Withdraw the manifold from the studs on the cylinder head. 7 Recover the gaskets from Ihe studs.

5B*1
Chapters PartB:
Ignition system - petrol models
Contents
General information 1 Ignition system - testing 2 Ignriton HT coil - removal, testing and refitting 3 Ignition timing - checking and adjustment 4 Igrrtion system - check See Chapter 1A Spark plugs - renewal See Chapter 1A
Degrees of difficulty

Easy,
suitable for Falrty easy, sulabte Fafety difficult, suitable for competent Difficult, suitable for Very difficult, ^ novice with littie
1
for beginner with Fafety difficult, suitable for competent experienced DIY suitable for expert DIY or professional ^ expenence 1 some experience DIY mechanic mechanic *
suitable for expert DIY or professional ^
Specifications
General System type
firing order Ignition timing at Idle speed (non-adjustable, for reference onlyy. 6-valve engines: Single-point injection engine with manual transmission .... Single-point injection engine with automatic transmission.. Multi-point injection engine 16-valve engines
Ignition
coil winding resistance (at 20°C): Primary Secondary
Weber-Marelli static (distributorless), wasted spark Ignition system controlled by engine management ECU
1
-3-4-2 (No 1 cylinder at timing belt end of engine)
10® ± 3° BTDC 6° ± 3° STDC 13° ±3° BTDC 8° x 3° BTDC
0.495 to 0.605 ohms 6660 to 8140 Ohms

Ignition system - petrol models 5B®3
Chapter 1A tor further information. Also check tnat tha accelerator cable is correctly adjusted
as
described in the relevant part of Chapter 4. If the engine is running very roughly, check the compression pressures and the valve clearances as descnbed In the relevant parts of Chapters 1 and 2. 2
H
these checks fall to reveal the cause of the problem, the vehicle should be taken to a suitably equipped Fiat dealer for testing. A wiring block connector Is Incorporated in the engine management circuit Into which a special electronic diagnostic tester can be plugged. The tester will locate the fault quickly and simply alleviating the need to test all the system components Individually which is a time consuming operation that carries a high risk of damaging the ECU. 3 The only Ignition system checks which can
oe
earned out by the home mechanic are those cescribed in Chapter 1A, relating to the spark plugs, and the ignition coll test descnbed In this Chapter. If necessary, the system wiring and wiring connectors can oe checked as descnbed in Chapter 12, Section 2, ensuring that the ECU wiring connector(s) have first
been
disconnected.
3 Ignition HT coil - ^ removal, testing and refitting
Removal 1 On 6-valve engines, unscrew the boll and remove the plastic cover from the left-hand
end
of the cylinder head (see Illustration). On 15-valve engines, remove the air cleaner, resonator and Inlet air duct as described in Chapter 4B. 2 Identify the two HT leads for position then disconnect them from the coil HT terminals jsee illustration). 3 Disconnect the LT wiring plug.
4 Unscrew the mounting bolts and remove the relevant ignition coil from the end of the cylinder head,
Testing 5 Testing of the coil consists of using a multimeter set to its resistance function, to check the primary and secondary windings for continuity and resistance. Compare the results obtained to those given In the Specifications at the start of this Chapter. Note the resistance of the coil windings varies slightly according to the coil temperature; the results In the Specifications are approximate values for the coil at 20°C. 6 Check that there is no continuity between the HT lead terminals and the coil body/ mourning bracket. 7 Note that with the ignition switched on and the engine stationary, voltage will only be supplied to the ignition cotls for approx-imately 2 seconds. However, when tho engine is being cranked or running, voltage will be continually supplied. 8 If faulty, the coil should be renewed.
Refitting 9 Refitting ts a reversal of the removal procedure ensuring that the winng and HT leads are correctly reconnected (see illustration).
4 ignition timing • checking and adjustment
1 The Ignition timing is constantly being monitored and adjusted by the engine management ECU, and although it is possible to check the base ignition liming using a standard timing light It is not possible to adjust it. 2 For those wishing to check the ignition timing a stroboscope timing light will be required, and it will need to be the type which
3.1 Removing the ignition coll cover
can determine the amount of advance from the TDC markings on the crankshaft pulley or flywheel. It Is recommended that the timing mark is highlighted as follows. 3 Remove the plug from the top of the transmission then turn tho engine slowly (raise the front right-hand wheel and engage 4th gear) until the timing mark scribed on the edge of the flywheel appears in the aperture. Highlight the line with quick-drying white paint - typist's correction fluid is ideal. 4 Start the engine and run It to normal operating temperature, then stop it. 5 Connect the timing light to No 1 cylinder spark plug lead (No 1 cylinder Is at the timing belt end of the engine) as described in the timing light manufacturer's Instructions. 6 Start the engine, allowing it to idle at the specified speed (Chapter 1A), and point the timing light at the transmission housing aperture. Adjust the timing light until the TDC marks are aligned with each other and read off the amount of advance. 7 If the ignition timing is incorrect, the car should be taken to a Fiat dealer who will be able to check the system quickly using special diagnostic equipment. 8 After making the check stop the engine, disconnect the timing light and refit the plug to the transmission.
3.2 HT terminals (1) and LT wiring plugs (2) on the two ignition colls 3.9 Ignition colt connections

6*1
Chapter 6
Clutch
Contents
Clutch - adjustment Clutch assembly - removal, inspection and refitting Clutch cable • removal and refitting Clutch hydraulic system - bleeding
Degrees of difficulty
2 Clutch master cylinder • removal and refitting 5 7 Clutch release mechanism - removal, Inspection and refitting 8 3 Clutch slave cylinder - removal and refitting 6 4 General information 1

Easy, suitable for
novice with little experience oi^

Faidy easy,
suitable for beginner
with
^
some
experience
Fairly difficult, suitable
for
competent ^
DIY
mechanic ^
Difficiit, suitable for ^ experienced DIY JR mechanic ^

V<*y difficult,
jk
suitable
for expert
DIY
« or professional ^
Specifications
General Type
Clutch pedal travel (cable-operated mechanism)
Friction plate diameter 8-valve petrol engines 16-valve petrol engines Diesel engines
Torque wrench setting Pressure plate retaining bolts
Single dry plate with diaphragm spring, cable- or hydraullcally-operated according to model 140.0 ± 5.0 mm
181.5 mm 190.0 mm 200.0 mm
Nm Ibf ft 16 12
1 General information
Vehicles with manual transmission are fitted with a pedal operated single dry plate clutch system. When the clutch pedal is depressed, effort is transmitted to the clutch release mechanism either mechanically by means of a cable, or hydraullcally by means of a master
2.5 Clutch cable adjustment
cylinder and slave cylinder. The release mechanism transfers effort to Ihe pressure plate diaphragm spring, which withdraws the pressure plate from the flywheel and releases the driven plate-Where applicable, the hydraulic fluid employed in the clutch system is the same as that used in the braking system, hence fluid is supplied to the master cylinder from a tapping on the brake fluid reservoir. The clutch hydraulic system must be sealed before work Is carried out on any of its components and then on completion, topped up and bled to remove any air bubbles.
2 Clutch - % adjustment §§ ^
Note: This procedure applies to models fitted with a cable-operated dutch
release
mechanism. No adjustment is possible on models with the hydrauHcaSy-operated system. 1 The clutch adjustment Is checked by measuring the clutch pedal travel. If a new cable has been fitted, settle it in position by depressing the clutch pedal at least thirty times. 2 Ensure that there are no obstructions
beneath the clutch pedal then measure the distance from the centre of the clutch pedal pad to the base of the steering wheel with the pedal In the at-rest position. Depress the clutch pedal fully to the floor, and measure the distance from the centre of the clutch pedal pad to the bata of the steering wheel. 3 Subtract the first measurement from the second to obtain the clutch pedal travel. If this is not with the range given in the Specifications at the start of this Chapter, adjust the clutch as follows. 4 The clutch cable Is adjusted by means of the adjuster nut on the transmission end of the cable. Access to the nut is from under the vehicle. Apply the handbrake then jack up the front of the vehicle and support on axle stands (see Jacking and vehicle support). 5 Working under the left-hand side of the engine compartment, slacken the locknut from the end of the clutch cable. Adjust the position of the adjuster nut. then depress the clutch pedal ten times and re-measure the dutch pedal travel. Repeat this procedure until the clutch pedal travel is as specified (see illustration). 6 Once the adjuster nut Is correctly positioned, and the pedal travel Is correctly set, securely tighten the cable locknut then lower the vehicle to the ground.

6*2 Clutch
3 Clutch cable -removal and refitting
Note: This procedure applies to models fitted with a cabfe-opemted dutch
release mechanism.
Removal 1 Remove the battery and tray as described In Chapter SA. If necessary, also remove the Inlet air ducting for Improved access as described In the relevant part of Chapter 4. 2 Unscrew the adjustment locknut and adjuster nut from the end of the cable fitting, (hen release the inner and outer cables from the transmission housing. Note the position of the damper biock. 3 Working Inside the vehicle, unhook the inner cable from the top of the clutch pedaL 4 Returning to the engine compartment, unscrew the nuts securing the outer cable to the bulkhead, then withdraw the cable assembly from the engine compartment. Refitting 5 Apply a smear of multi-purpose grease to the cable end fittings, then pass the cable through the bulkhead. Refit and tighten the nuts. 6 Inside the vehicle hook the inner cable onto the top of the clutch pedal. 7 in the engine compartment, attach the outer cable to the transmission housing and refit the damper block and nuts lo Ihe inner cable end. fi Adjust the cable as described in Section 2. 9 Refit the air ducting and battery with reference to Chapters 4 and 5A
4 Clutch hydraulic system -
i
Note: This procedure applies to models fitted with the hydraulicalty-operated clutch release mechanism.

A


Warning: Hydraulic fluid Is poisonous; thoroughly wash off spllfs from bare skin without delay. Seek Immediate medical advice If any fluid is swallowed or gets into the eyes. Certain types of hydraulic fluid are Inflammable and may ignite when brought into contact with hot components; when servicing any hydraulic system, It is safest to assume that the fluid IS Inflammable, and to take precautions against the risk of fire as though ft were petrof that was being handled. Hydraulic fluid Is an effective paint stripper and will also attack many plastics. If spillage occurs onto painted bodywork or fittings, ft should be washed off Immediately, using copious quantities of fresh water. It Is also hygroscopic - It can absorb moisture from the air, which then renders it useless. Old fluid may have
suffered contamination, and should never be re-used. When topping-up or renewing tho fluid, always use tha recommended grade, and ensure that It comes from a new seated container. General information 1 Whenever the clutch hydraulic lines are disconnected for service or repair, a certain amount of air will enter the system. The presence of air In any hydraulic system will Introduce a degree of elasticity, and in the clutch system this will translate into poor pedal feel and reduced travel, leading to inefficient gear changes and even clutch system failure. For this reason, the hydraulic lines must be sealed using hose clamps before any work la carried out and then on completion, topped up and bled to remove any air bubbles. 2 To seal off Ihe hydraulic supply to tha clutch slave cylinder, fit a proprietary brake hose clamp to the flexible section of the hose located over the transmission and tighten it securely. It will be necessary to remove the battery and battery tray to access the hose. 3 The most effective way of bleeding the clutch hydraulic system is to use a pressure brake bleeding kit. These are readily available in motor accessories shops and are extremely effective: the following sub-section describes bleeding the clutch system using such a kit. The alternative method is to bleed the system by depressing tho clutch pedal • refer to Chapter 9. Section 11, for details of this method.
Bleeding 4 Remove the protective cap from Ihe bleed nipple on the slave cylinder. Access can be improved by removing the battery and tray with reference to Chapter 5A. 5 Fit a ring spanner over the bleed nipple head, but do not slacken it at this point. Connect a length of dear plastic hose over the nipple and insert the other end into a clean container. Pour hydraulic fluid into the container, such that the end of the hose is covered. 6 Following the manufacturer's instructions, pour hydraulic fluid into the bleeding kit vessel 7 Unscrew the vehicle's fluid reservoir cap, then connect Ihe bleeding kit fluid supply hose to the reservoir. 8 Connect the pressure hose to a supply of compressed air - a spare tyre is a convenient source. Caution: Check that the pressure In the tyre does not exceed the maximum supply pressure quoted by the kit manufacturer, let soma sir escape to reduce the pressure, if necessary. Gently open the air valve and allow the air and fluid pressures to equalise. Check that there ere no teaks before proceeding. 9 Using the spanner, slacken the bleed pipe nipple until fluid and air bubbles can be seen to flow through the tube, into the container.
Maintain a steady flow until the emerging fluid la free of air bubbles; keep a watchful eye on the level of fluid in the bleeding kit vessel and the vehicle's fluid reservoir • if it Is allowed to drop too low, air may be forced into the system, defeating the object of the exercise. To refill the vessel, turn off the compressed air supply, remove the lid and pour In en appropriate quantity of clean fluid from a new container - do not re-use the fluid collected in the receiving container. Repeat as necessary until the ejected fluid is bubble-free. 10 On completion, pump the olutch pedal several times to assess its feel and travel. If firm, constant pedal resistance is not felt throughout the pedal stroke, it i6 probable that air Is still present in the system - repeat the bleeding procedure untii the pedal feel is restored. 11 Depressurise the bleeding kit and remove it from the vehicle. At this point, the fluid reservoir may be over-full; the excess should be removed using a clean pipette to reduce the level to the MAX mark. 12 Tighten the bleed pipe nipple using the spanner and remove the receiving container. Refit the protective cap. 13 On completion, assess the feel of the clutch pedal; if it exhibits any sponginess or looseness, further bleeding may be required. 14 Where removed, refit the battery and tray. 15 Finally, road test the vehicle and check the operation of the clutch system whilst changing up and down through the gsar9. whilst pulling away from a standstill and from a hill start.
5 Clutch master cylinder - & removal
and
refitting 5 S Note: This procedure applies to models
fitted
with the hydraulically-operated dutch
release
mechanism. Note: Refer to the warning at Ihe beginning
of
Section 4 regarding the hazards of
working
with hydraulic fluid.
Removal 1 Disconnect the battery negative terminal (refer lo Disconnecting the battery in the Reference Section of this manual). 2 Remove the air cleaner and air ducting as described in the relevant Part of Chapter 4. 3 For improved access on petrol engine models, remove the alternator as described In Chapter 5A. 4 Fit a brake hose clamp to the hose between the hydraulic fluid reservoir and the clutch master cylinder. Alternatively syphon ail the fluid from the reservoir. 5 Disconnect the fluid supply hose at the master cylinder, then unscrew the union nut and disconnect the hydraulic pipe from the cylinder outlet. Be prepared for some fluid loss by placing some rags beneath the master cylinder.

Automatic transmission 7B*3
11 When reverse gear Is selected, the control unit keeps the transmission In tow ratio, if this were not the case, it would, In theory, be possible to drive as fast In reverse as in forward gear. 12 An electronic control unit supplies the current to energise the clutch. The control unit receives signals concerning engine speed, road speed, accelerator pedal position, and gear selector position, Sensors include the following. a) Engine rpm sensor (from the Injection/ignition control unit) b) Accelerator pedal switch
c) Throttle valve position sensor d) Selector lever position sensor e) Vehicle speed sensor f) Coolant temperature sensor g) Air conditioning sensor h) Brake switch I) Torque signal
13 The final drive/differential unit Is conventional. Drive from the driven pulley is transmitted to the differential by an Intermediate reduction gear. 14 The ECVT incorporates a warning light which illuminates when a fault occurs.
Precautions 1$ Observe the following precautions to avoid damage to the automatic transmission: a) Do not attempt to start the engine by pushing or towing the car. b) If the car has to be towed for recovery, the distance must not exceed 12 miles (20
km),
and the speed must not exceed
19
mph
(30 kph).
If these conditions cannot be met, or If transmission damage is suspected, only tow the car with the front wheels clear of the ground. c) Only engage P or R when the vehicle is stationary.
1.1b Electromagnetic f Coil 2 Signal from vehicle speed sensor 3 Transmission 4 Electromagnetic powder 5 Drive shaft (driven by crankshaft) $ Transmission input shaft 7 Electromagnetic clutch housing 8 ECVT control unit
clutch control system 9 Accelerator pedal micro switch 10 Throttle
vafve
opening position potentiometer 11 Multifunction switch 12 Ignition switch
13
Air conditioning
signal
14 Engine PPM
signal
15 Accelerator pedal 16 Coolant temperature signal 17 Injection/ignition control unit 18 8attery
1.1c Hydraulic control system 3 Injection/ignition control unit 4 Air conditioner sensor
signal
6 Coolant temperature signal 7 Clutch signal 8 Engine RPM
signal
9 ECVT warning light 10 Selector lever position 11 Accelerator
pedal
switch/throttle
valve
potentiometer/torque signal 12 Brake switch 13
ECVT
control unit 14 Signal from vehicle speed sensor
15
Accelerator pedal position switch
16 Pulley ratio 17 Input shaft RPM 18 Primary oil pressure
19
Primary pulley 20 Electromagnetic clutch 21 Pressure regulating solenoid valve 22 Oil pressure control valve 23 Secondary oil pressure 24 Slip ring 25 Drive from engine 26 Oil pump 27 Vehicle speed sensor 28 Secondary pulley 29 Belt and pulley 30 Drive to drlveshafts

7B*6 Automatic transmission
Gear selector cable -adjustment
1 Remove the battery and tray as described In Chapter 5A for access to the transmission. 2 Disconnect the selector cable from the lever on Ihe transmission. 3 Move the selector fever inside the vehicle to the N (Neutral) position, then move the lever on the transmission to Its central (Neutral) position. Locate the cable end over the lever. If the cable end fitting does not line up exactly with the hole In Ihe lever, loosen the adjustment nut and reposition the end fitting. 4 With the adjustment correct reconnect tha cable to the lever, then move the selector lever to the P (Park) position. Check that the lever on the transmission has also moved to the P position. 6 Refit the battery and tray as described in Chapter 5A. 6 Road test the vehicle, and check for correct operation in all selector lever positions.
9 Gear selector cable -removal and refitting at
7 Inside the vehicle disconnect the selector cable from the bottom of the selector lever (hen remove it from the support bracket, a Withdraw the cable into the engine compartment, and remove it.
Refitting 9 Refitting is a reversal of removal, but adjust the cable as described in Section 8. 10 Check that It is only possible to start the engine in positions P and N. Reposition the selector lever switch If necessary. 11 Road test the vehicle, and check for correct operation In ell selector lever positions.
10 Transmission oil pump - & mnvtiifll rAtiMlitA removal a/id refitting
Removal 1 Using an Allen key. unscrew the screw and remove the selector lever knob from the lever. 2 Remove the oddment tray and the ashtray. 3 Remove the screws and withdraw the centre console and selector mechanism cover. 4 Unscrew the mounting screws, slightly lift the centre console, then disconnect the wiring and remove the console, 5 Remove the battery and tray as described in Chapter 5A for access to the transmission, 6 Disconnect the selector cable from the lever on the transmission.
Removal 1 Apply the handbrake, then lack up the front of the vehicle and support on axle stands (see Jacking and vehicle support). Remove the left-hand wheel. 2 Unscrew the screws and remove the wheel arch liner. 3 Working through the left-hand wheel arch, remove Ihe three bolts which secure the oil pump. 4 Attach a slide hammer to the oil pump, using the two tapped holes provided. Withdraw the pump using the slide hammer. Be prepared for some oil spillage. Recover the gasket end O-ring (see illustrations). 5 If the pump is defective, it must be renewed; no spares are available.
Refitting 6 Before refitting Ihe oil pump, clean Ihe mating surfaces of the transmission and pump. 7 Rt the oil pump, U9ing a new gasket and a new O-ring. Secure the pump with the three bolts.
8 Refit the wheel arch liner, then refit tto wheel and lower the vehicle to the ground. 9 Check the transmission fluid level » described earlier in this Section, and top-upif necessary.
11 Accelerator pedal & mfcro-Bwftcb(es) -checking
and
adjustment ^
1 Correct adjustment of the micro-awtlch which senses the accelerator pedal position s essential for correct operation of the clutch.
A
quick check can be made by listening for the switch clicking as the accelerator a depressed. For an accurate check, proceed as follows. 2 Disconnect Ihe mlcroswitch wiring connector (nside the vehicle. Connect a continuity tester across the terminals of the switch, located at the top of (he pedal box (see Illustration}. 3 Remove the air cleaner and air ducting as described in Chapter 4A. 4 With the accelerator pedal releassd, th« switch must be closed (zero resistance). Slowty depress the pedal, and check that the switch opens when the throttle valve on the throttle housing is 30° open. This will occur when the pedal has travelled between 3 and 7 mm. Adjust the switch position if necessary. 5 If the switch is permanently open or permanently closed, and adjustment makes no difference, renew ft. 6 Remake the original wiring connections on completion,
12 Automatic transmission -overhaul
Apart from the operations described earlier in this Section, transmission overhaul should be entrusted to a Rat dealer or transmission specialist.
10.4a Using a slide hammer to remove the oil pump from the transmission 10.4b Automatic transmission oil pump O-dng (1), housing (2) and gasket (3) 11.2 Continuity tester connected ecross the accelerator pedal micro-switch

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

A


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

A


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)