1997 FIAT PUNTO pump

Fuel system - diesel models 4C*3
14.6 Nuts securing the exhaust downpipe to the exhaust manifold 14.8 Disconnecting the oil return pipe from tho turbocharger
13 Turbocharger -description and precautions
Description A turbocharger 1$ fitted to TDS, TD and SX models. It increases engine efficiency by raising the pressure In the inlet manifold above atmospheric pressure. Instead of the air simply being sucked Into the cylinders. It Is forced in. Additional fuel is supplied by the injection pump in proportion to the increased air inlet. Energy for the operation of the turbocharger comes from the exhaust gas. The gas flows through a specially-shaped housing (the turbine housing) and In so doing, spins the turbine wheel. The turbine wheel is attached lo a shaft, at the end of which is another vaned wheel known as the compressor wheel, The compressor wheel spins in Its own housing, snd compresses the inlet air on the way to the inlet manifold. Boost pressure (the pressure in the Inlet manifold) is limited by a wastegate, which diverts Ihe exhaust gas away from the turbine wheel In response to a pressure-sensitive actuator. A pressure-operaled switch operates a warning light on the instrument panel in the event of excessive boost pressure developing. The turbo shaft is pressure-lubricated by an oil feed pipe from the main oil gallery The shaft floats on a cushion of oil. A drain pipo returns the oil to the sump.
Precautions The turbocharger operates at extremely high speeds and temperatures. Certain precautions must be observed, to avoid premature failure of the turbo, or injury to the operator. Do not operate the turbo with any of its parts exposed, or with any of ils hoses removed. Foreign objects falling onto the rotating vanes could cause excessive
damage, and (if ejected) personal injury. Do not race the engine immediately after start-up, especially if it Is cold. Give the oil a few seconds lo circulate. Always allow the engine to return to idle speed before switching il off - do not blip the throttle and switch off, as this will leave the turbo spinning without lubrication. Allow the engine to idle lor several minutes before switching off after a high-speed run. Observe the recommended intervals for oil and filter changing, and use a reputable oil of the specified quality. Neglect of oil changing, or use of Inferior oil, can cause carbon formation on the turbo shaft, leading to subsequent failure.
14 Turbocharger -removal and refitting
8 Disconnect the oil return pipe from the turbocharger (see Illustration). 9 Unscrew the bolt securing the mounting bracket to the cyfindar block. 10 Unscrew the mounting nuts and withdraw the turbocharger from the studs in Ihe exhaust manifold. Recover the gasket. II It Is to be refitted, store the turbocharger carefully, and plug its openings to prevent dirt ingress.
Refitting 11 Refitting Is a reversal of removal, bearing in mind the fallowing points: a) if a new turbocharger Is being fitted, change the engine oil and filter. b) Tighten ail nuts and bolts to the specified torque. c) Before starting the engine, prime the turbo lubrication circuit by disconnecting the stop solenoid iead at the injection pump, and cranking the engine on the starter for three ten-second bursts.
Removal 1 Remove the battery as described in Chapter 5A. 2 Unbolt and remove the relay guard and bracket from the left-hand side of Ihe engine. 3 Remove the air cleaner and ducting as descnbed in Section 2. 4 Loosen the clips and remove the air outlet duct between tho turbocharger and inlet manifold. Also disconnect the air inlet duct from the turbocharger. 6 Appty the handbrake, then jack up tho front of the vohicle and support on axle stands (see Jacking and vehicle support). 6 Bend back the locking tabs (if fitted) and unscrew the nuts securing the exhaust downpipe lo the exhaust manifold (see Illustration). Disconnect the downpipe from the exhaust system (refer to Part 4D) end remove it from under the vehicle. Recover tne gasket. 7 Unscrew ihe union nut and disconnect the oil supply pipe from the turbocharger. Recover the copper ring and tape over the end of the pipe 10 prevent dust entry.
15 Turbocharger -examination and renovation l
1 With the turbocharger removed, inspect the housing for cracks or other visible damage. 2 Spin the turbine or the compressor wheel, to verify that the shaft is intact and to feel for excessive shake or roughness. Some play is normal, since in use, the shaft is floating on a film of oil. Check that the wheel vanes are undamaged. 3 The wastegate and actuator are Integral, and cannot be checked or renewed separately. Consul! a Flat dealer or other specialist If it is thought that testing or renewal is necessary. 4 If tho exhaust or induction passages are ail* contaminated, Ihe turbo shaft oil seals have probably failed. 6 No DIY repair of the turbo is possible. A new unit may be available on an exchange basis,

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.

5A«2 Starting and charging systems
5.9a Unbolting the alternator upper bracket from the rear of the coolant pump
fl Loosen the pivot bolt and adjustment locknut then unscrew the adjustment bolt and swivel the alternator towards the engine so that the drivebefi may be slipped off the alternator pulley. 9 Unscrew and remove the pivot and adjustment bolts and withdraw the alternator Irom the engine compartment. If preferred the upper alternator bracket may bo unbolted from the rear of the coolant pump {see illustrations).
Refitting 10 Refitting is a reversal ot removal. Refer to Chapter tA or 1B as applicable for details of tensioning the auxiliary drivebeit. On completion lighten the pivot and adjustment botts/nut to the specified torque.
6 Alternator -brush holder/regulator module renewal
%
1 Remove the alternator as described in Section 5. 2 Extract the two small bolts and withdraw the brush box. Note the small plastic grille on the Marelli alternator (see illustrations), 3 Using a steol rule chock the length of the brushes. If less than 5.0 mm the complete brush holder assembly should be renewed. Note: On Bosch alternators it may be possible to obtain the brushes separate//, in which case the brush ieads should be unsoldered
5.9b Removing the pivot bolt and alternator from the engine
from ihe terminals and the new brush leads soldered onto the terminals. 4 Check the slip rings for excessive wear and clean them with a rag soaked in fuel. 5 Pit the new holder using a reversal of the removal procedure but make sure that each brush moves freely.
7 Starting system • & testing
Note: Refer to Ihe precautions given In Safety firstI and in Section I of this Chapter before stoning work. 1 If the starter motor falls to operate when the Ignition key Is turned to the appropriate position, the following possible causes may be to blame. aj The battery is faulty. b) The electrical connections between the switch, solenoid, battery and starter motor are somewhere failing to pass the necessary current from the battery through the starter to earth. c) 77:© solenoid is faulty. d) The starter motor is mechanically or electrically defective. 2 To check the battery, switch on the headlights. If they dim after a few seconds, this indicates that the battery is discharged -recharge (see Section 2) or renew the battery. If the headlights glow brightly, operate the ignition switch and observe the lights. If they
dim, then this indicates that current it reaching the starter motor, therefore the iao8 must lie In the starter motor. If the lights continue to glow brightly (and no clicking sound can be heard from the starter motor solenoid), this indicates that there is a lairt
In
the circuit or solenoid - see following paragraphs, if the starter motor turns siowfy when operated, but the battery is In good condition, then this indicates that either lae starter motor is faulty, or there is considers resistance somewhere in the circuit. 3 If a fault in the circuit is suspected, disconnect the battery ieads (including ihe earth connection to the body), lt» starter/solenoid wiring and tne engine/transmission earth strap. ThoroygWy clean the connections, and reconnect the leads and wiring, ihen use a voltmeter or J«i lamp to check that full battery voltage is available at the battery positive lead connection to the solenoid, and that the earth is sound. Smear petroleum jelly around ttie battory terminals to prevent corrosion > corroded connections are amongst the most frequent causes of electrical system faults. 4 If the battery and all connections are in good condition, check the circuit disconnecting the wire from the solenod blade terminal. Connect a voltmeter or less lamp between the wire end and a good earth (such as the battery negative terminal), ais check that the wire is live when tne ignition switch is turned to the start position. If It is. then the circuit is sound - if not. the circut wiring can be checked as described Chapter 12. Section 2. 5 The solenoid contacts can be checked
Oy
connecting a voltmeter or test lamp across Ihe solenoid. When the ignition switch is turned to the start position, there should b»a reading or lighted bulb, as applicable. II thars is no reading or lighted bulb, the solenoid is faulty and should be renewed. 6 If the circuit and solenoid are proves sound, the fault must lie in the starter motor. In this event, it may be possible to have tre starter motor overhauled by a specialist, but check on the cost of spares before proceeding, as It may prove more economical to obtain a new or exchange motor

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.

7A«4 Manual transmission
33 Remove lha air cleaner front section and air ducting with reference to Chapter 4C. Also disconnect the injection pump vacuum pipe from the clips on the left-hand end of the cylinder head. This work is necessary in order to fit the engine hoist 34 Support the weight of the engine using a hoist attached to the engine lifting eyes, or alternatively use a trolley Jack and block of wood beneath the engine. 35 Unscrew the nuts securing the downpipe to the exhaust manifold, then lower it and support on an axle stand. Recover the gasket. 36 Unscrew the starter motor mounting bolts and support the starter motor to one side. 37 Disconnect the wiring from the reversing light switch on the front of the transmission. 38 Unscrew the nut and disconnect the earth cable from its stud. 39 Trace the wiring back from the electronic speedometer sensor and disconnect the connector located on the left-hand side ot the engine. If a mechanical speedometer Is fitted unscrew the knurled collar and disconnect the cabte from the transmission. 40 Unbolt and remove the transmission lower cover. 41 Using an Allen key unscrew the bolts securing the inner end of the left-hand driveshaft to the transmission flange. Remove the bolts and recover the spacer plates. Support the driveshaft on an axle stand. 42 Unscrew and remove the bolts securing the left-hand swivel hub assembly to the front suspension strut, then separate the components and support the swivel hub on an axle stand. 43 Move the swrvel hub assembly outwards and support the driveshaft away from Ihe transmission. 44 Using an Allen key unscrew the bolts securing the Inner end of the right-hand driveshaft to the intermediate shaft flange. Remove the bolts and recover the spacer plates. Support the driveshaft on an axle stand. 45 Remove the intermediate driveshaft with reference to Chapter 8. 46 Working beneath the vehicle, unscrew the bolts securing the rear engine mounting to the underbody then unscrew the bolts securing the mounting to the transmission and withdraw the mounting assembly from under the vehicle.
47 Unscrew the bolts securing the left-hand engine/transmission mounting to the body then unscrew Ihe bolts from the transmission and remove the mounting. 48 Support the weight of the transmission on a trolley jack then unscrew the remaining nut and bolts from the bellhousing and pull the transmission away from the engine.

A


Warning: Support the trans-mission to ensure that It remains steady o/i the jack head. Keep the transmission level until the Input shaft
1$
fully withdrawn from the clutch friction plate.
Refitting 48 Refitting is a reversal of the removal procedure, but note the following points. a) Appiy a smear* of high-meiting-point grease to the clutch friction piate splines; take care to avoid contaminating the friction surfaces. b) Tighten all bolts to the specified torque. c) Fit new clips to secure the driveshaft gaiters to the transmission output shafts. d) Adjust the clutch cable (where applicable) as described In Chapter 6.
4 Manual transmission overhaul -general Infomtatlon
Overhauling a manual transmission is a difficult and Involved Job for the DIY home mechanic. In addition to dismantling and reassembling many small parts, clearances must be precisely measured and, if necessary, changed by selecting shims and spacers. Internal transmission components are also often difficult to obtain, and in many Instances, extremely expensive. Because of this, If the transmission develops a fault or becomes noisy. Ihe best course of action is to have the unit overhauled by a specialist repairer, or to obtain an exchange reconditioned unit. Nevertheless, it is not impossible for the more experienced mechanic to overhaul the transmission, provided the special tools are available, and the Job is done in a deliberate step-by-step manner, so that nothing is overlooked.
The tools necessary for an overhaul include internal and external clrclip pliers, bearing pullers, a slide hammer, a sat of pin punches, a dial test Indicator, and possibly a hydraulic press. In addition, a large, sturdy workbench 8od a vice will be required. During dismantling o1 the transmission, make careful notes of how each component
1$
fitted, to make reassembly easier and more accurate. Before dismantling the transmission, it will help if you have some idea what area is malfunctioning. Certain problems can be closely related to specific areas In the transmission, which can make component examination and replacement easier. Refer to the Fault Finding Section at the end of this manual for more Information.
5 Reversing light switch -testing, removal and refitting ||
Testing 1 The reversing light circuit is controlled by a plunger-type switch screwed into the front of the transmission casing. If a fault develops, first ensure that Ihe circuit fuse has not blown. 2 To test the switch, disconnect the wiring connector, and use a multimeter (set to the resistance function) or a battery-and-bulb test circuit to check that there is continuity between the switch terminals only when reverse gear is selected. If this is not the case, and there are no obvious breaks or other damage to the wires, the switch is faulty, and must be renewed.
Removal 3 Access to the reversing light switch Is best achieved from under the vehicle. Apply the handbrake then jack up Ihe front of the vehicle and support on axle stands (see Jacking and vehicle support). 4 Disconnect the wiring connector, then unscrew It from the transmission casing.
Refitting 5 Refit the switch and tighten securely. 6 Reconnect the wiring then lower the vehicle to the ground.

7B«1
Chapter 7 Part B:
Automatic transmission
Contents
Accelerator pedal micro-switch(es) - checking and adjustment II Automatic transmission filter and fluid change See Chapter 1A Automatic transmission fluid level check See Weekly checks Automatic transmission • overhaul 12 Automatic transmission • removal and refining 2 Bectro-magnetic clutch - removal, inspection and refitting 3 BectrO'fnagnetic clutch brushes- removal, inspection and refitting . 4
Electronic control unit - removal and refitting 5 Gear selector cable - adjustment 6 Gear selector cable - removal and refitting 9 General information 1 Kickdown cable - adjustment 7 Kickdown cable - removal and refitting 6 Transmission oil pump - removal and refitting 10
Degrees of difficulty

Easy,
suitable for novice
with
ittle experience ^
Party
easy,
suitable for beginner
with
^r someexperienoe ^
Faiily
difficult,
^ suitable
for
competent
DIY mechanic
^

Difficult, suitable
for fe, experienced DIY >8J mechanic
Verydfficult, ^
suitable
for
expert DIY
or professional ^
Specifications
General Type Ratios (at transmission): Lowest Highest Final drive
Torque wrench settings Esnh cable Control unit Sectro-magnetic clutch to flywheel Transmission-to-engine bolt/nut ..
ECVT (Electronic Continuously Variable Transmission)
2.503 0.497 4.647:1
Nm Ibftt 14 10 5 4 34 25 85 63
1 Genera) information
I The automatic transmission fitted is designated ECVT (Electronic Continuously Variable Transmission). The main components
01
the transmission are an electro-magnetic dutch, a variable-ratio coupling, a final drive/ differential unit, and the associated control mechanisms (see illustrations overleaf) 2 The variable-ratio coupling consists of two pulleys and a flexible metal drivebelt. The effective diameter of the two pulleys can be varied to provide different transmission ratios between them. 3 During normal driving, the transmission automatically selects the ratio giving the best
compromise between economy and speed. When the driver depresses the accelerator pedal to the floor, a kickdown effect is provided, and the transmission selects a lower ratio for improved acceleration. 4 The gear selector control resembles that fitted to conventional automatic transmissions. The control positions are as follows: P (Parking) The transmission is mech-anically locked by the engage-ment of a pawl with a toothed segment on the driven pulley. R (Reverse) Reverse gean's engaged, N (Neutral) The transmission is In neutral. D (Drive) Normal driving position. Trans-mission ratio is varied automat-ically to suit prevailing speed and load.
L (Low) Prevents the transmission
moving into high ratios. Provides maximum acceleration end maximum engine braking. 5 The engine can only be started In positions P and N. A warning buzzer sounds If the selector is in any position other than P when the ignition is switched off or when the driver's door is opened. 6 The electro-magnetic clutch consists of a driving element boiled to the engine flywheel, and a driven element spiined to the transmission Input shaft. The degree of coupling between the (wo elements Is determined by the intensity of a magnetic field generated by a current passing through windings in the driven element. The magnetic field acts on a layer of metallic powder between the driving and driven elements. When no magnetic field is present, the powder is loose and the two elements are effectively

7B*2 Automatic transmission
disconnected. As the magnetic field increases, the powder sticks together, and the coupling between Ihe elements becomes Increasingly rigid. 7 Selection of reverse, neutral and forward gears is by the movement of a sliding sleeve on a hub keyed to the drive pulley shaft. In forward gear, the sleeve engages with the gear on the end of the input shaft, which is then locked to the drive pulley shaft. When reverse is selected, the sleeve engages with reverse driven gear, which is in constant mesh with an idler gear driven by transfer gears from the input shaft gear. In neutral, the sleeve Is in an intermediate position, and the
two shafts are not connected. 8 Tho drive pulley and driven pulley both consist of fixed and moving halves. The movement of ihe drive pulley halves is controlled hydraulically, while the driven pulley halves move under the influence of a spring and the tension exerted by the drivebeit. As the drive pulley opens, the driven pulley closes, and vice-versa. In this way, the transmission ratio between the two pulleys can be varied. The ratios are continuously variable between preset limits; the difference between the lowest and highest ratios available is approximately 5:1. 9 Hydraulic pressure is generated by a gear-
type pump Inside the transmission. The punp driveshaft runs inside the Input and drive pulley shafts, and Is splined to the centred the engine flywheel. This means that hydreulc pressure is only generated when the engine is running, which is why a car with this type ot transmission cannot be push- or tow-started 10 Application of hydrautic pressure to the pulley halves is via a control unit, which receives information on accelerator pedal position, transmission selector lever position, transmission ratio currently in use, and drive pulley speed. From this information, the control unit determines whether, and in which direction, lo change the pulley ratios.
1.1 a Cutaway view of the ECVT (electronic continuously variable transmission) 7 Electromagnetic dutch 3 Drive pulley 5 Metal drivebeit 7 Hydraulic controt unit 2 Gear selector sleeve A Dnven pulley 6 Final drive reduction gears

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