1983 FIAT UNO parking sensors

1 General description
The electrical system is of 12 volt negative
earth type and employs a belt-driven
alternator and a pre-engaged type starter
motor.
The models in the range are all adequately
equipped with electrical accessories, while SX
versions also have power windows and
centralised door locking plus a check control
system (Section 34).
2 Battery- inspection, charging,
removal and refitting
2
1The battery is of maintenance-free type and
under normal circumstances, no topping up
will be required, but regularly check that the
electrolyte level is between the minimum and
maximum lines on the translucent battery
casing.
2If the electrolyte level does drop below theminimum line, suspect a leak in the battery
casing or that the alternator is overcharging. If
the latter is the case, rectify the alternator fault
and then prise out the two rectangular plugs
from the top of the battery and top up with
distilled or purified water.
3Always keep the battery terminals clean
and smear them with petroleum jelly to
prevent corrosion.
4The battery will normally be kept fully
charged by the alternator, but it is possible for
the battery to become discharged if the daily
mileage is very low with much use being
made of the starter and electrical accessories.
5When the battery begins to deteriorate with
age it may also require a boost from a mains
charger.
6Disconnect both battery leads before
connecting the mains charger. 7To remove the battery from the car, first
disconnect the leads from the battery
terminals (earth first) and then unscrew the
securing clamp from the casing projection at
the base of the casing (photo).
8Lift the battery from its mounting platform.
Refitting is a reversal of removal. Reconnect
the earth cable last.
Fuses
Circuit protected Fuse rating (A)
1 Stop lamps, direction indicator lamps, instrument panel warning
lamps, tachometer economy gauge, check control system . . . . . . 10
2 Windscreen wiper and washer, rear screen wiper/washer, check
system panel illumination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
3 Left front parking, right rear tail lamp, cigar lighter illumination,
heater control and clock, digital clock illumination . . . . . . . . . . . . . 7.5
4 Right front parking lamp and left rear tail lamp, instrument panel
illumination and rear number plate lamp . . . . . . . . . . . . . . . . . . . . . 7.5
5 Left-hand dipped headlamp, rear foglamps . . . . . . . . . . . . . . . . . . 10
6 Right-hand dipped headlamp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
7 Left-hand headlamp (main beam) . . . . . . . . . . . . . . . . . . . . . . . . . . 10
8 Right-hand headlamp (main beam) . . . . . . . . . . . . . . . . . . . . . . . . . 10
9 Engine cooling fan and horn (Comfort) . . . . . . . . . . . . . . . . . . . . . . 25
10 Heater booster fan, digital clock map reading lamp . . . . . . . . . . . . 20
11 Heated tailgate glass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
12 Courtesy lamps, cigar lighter, radio power feed, disc pad
sensors, economy gauge (ES models) . . . . . . . . . . . . . . . . . . . . . . 10
13 Hazard warning lamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
14 Spare (Comfort), Horn (Super) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
BulbsWattage
Headlamp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40/45 or Halogen H4 60/55
Front parking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Side repeater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Tail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Stop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Reversing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Rear foglamp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Direction indicator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Rear number plate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Courtesy lamp (roof) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Courtesy lamp (pillar) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Warning and indicator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Wedge base
Torque wrench settingsNm lbf ft
Alternator mounting and adjustment nuts . . . . . . . . . . . . . . . . . . . . . . . 50 87
Starter motor bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 35
9•2 Electrical system
2.7 Battery clamp
If battery terminal corrosion
has occurred, it may be
neutralised by applying
sodium bicarbonate or
household ammonia.

3The centralised door locking system can
operate independently of the key.
4To gain access to the lock solenoid and
linkage, remove the front door trim panel as
described in Chapter 12.
5Disconnect the battery negative lead.
6Disconnect the electrical wiring plugs from
the solenoid within the door cavity.
7Disconnect the solenoid from the lock lever
by removing the clip.
8Unscrew the two bolts which secure the
solenoid to the door and remove it.
9Renew the solenoid or switch as necessary.
10Refitting is a reversal of removal.
11Refer to Section 10 for details of system
fuses and relays.
33 Economy gauge
(Econometer)
2
1This device is fitted to ES (energy saving)
models and indicates to the driver the fuel
consumption (in litres per 100 km) coupled
with a needle which moves over coloured
sections of a dial to make the driver aware
that his method of driving is either conducive
to high or low fuel consumption. Refer to
Chapter 3, Section 16.
2The device is essentially a vacuum gauge
which also incorporates a warning lamp to
indicate to the driver when a change of gear is
required.
3A fuel cut-out valve (see Chapter 3, Sec-
tion 11) is used in conjunction with the
economy gauge so that when the accelerator
pedal is released during a pre-determined
engine speed range, fuel supply to the engine
is stopped, but resumes when the engine
speed falls below the specified range.
LED (light emitter diode)
4The gearchange indicator will only light up
at engine speeds in excess of 2000 rev/min
for vacuum pressures up to 600 mm Hg in 1st,
2nd and 3rd speed gears and for vacuum
pressures up to 676 mm Hg in 4th speedgear. The light will not come on if 5th speed
gear is engaged or if the coolant temperature
is below 55ºC.
5There is a two second delay in the light
coming on to prevent it operating during rapid
acceleration in a low gear.
6If the LED light comes on during
deceleration it should be ignored.
Fault finding
7A faulty economy gauge should be checked
in the following way.
8Refer to Section 21 and remove the
instrument panel.
9Disconnect the economy gauge L
connector and then connect a test lamp
between the BN cable contact and earth. If
the lamp comes on then the gauge supply
circuit is not open. If the lamp does not come
on, check all connections in the supply cable
which comes from the interconnecting unit of
the electrical system, also Fuse No 12.
10Now connect a voltmeter between the
white cable and earth. Check the voltage with
the engine not running, but the ignition
switched on. It should be between 0.7 and
0.9 volt. If the reading varies considerably
from that specified, check the connections
between the economy gauge and the fuel
cut-out device control unit. If the fault cannot
be rectified, renew the ignition control unit
(Digiplex system, see Chapter 4).
11Now check the closed throttle valve plate
switch by connecting a voltmeter between the
brown and BN cables of the L connector. With
the valve plate open, there should be no
reading, but with it open, voltage should be
indicated.
12Failure to conform as described will be
due to a faulty earth in the switch or a faulty
fuel cut-out device control unit.
13A further test of the throttle valve plate
switch may be carried out by disconnecting
the multi-plug from the fuel cut-out device
control unit.
14Connect a test lamp to contact 4 (positive
battery terminal). The lamp should come on,
when the engine is idling or the accelerator
released. If it does not, renew the throttle
valve plate switch.15Connect a tachometer to the brown/white
cable contact in the L connector and record
the engine speed with the engine running. If
no reading is obtained, renew the Digiplex
ignition control unit which must be faulty.
34 Check control (warning
module) system
2
1This is fitted into the instrument panel of
certain models to provide a means of
checking the operation of many electrical
circuits and other systems in the interest of
safety. Sensors are used where appropriate.
2The following components are not
monitored by the system, but have separate
warning lamps:
Handbrake “on”
Choke in use
Low engine oil pressure
Battery charge indicator
3The multi-functional electronic device
automatically checks the following functions
whether the engine is running or not:
Coolant level
Disc pad wear
Door closure
Engine oil level
Front parking lamps
Rear foglamps
Stop lamps
4The check information is stored by the
system monitor until the engine is started
when the display panel then indicates the
situation by means of the LEDs (light emitter
diodes) and the general lamp.
5If all functions are in order, the green panel
lamp will come on when the ignition key is
turned and will go out after two to three
seconds.
6If some functions are not in order, then the
red panel lamp will come on also the
appropriate LED.
Sensors - checking
7If a fault signal occurs which is
subsequently found to be incorrect, first
check the wiring connections between the
9•12 Electrical system
Fig. 9.15 Check system control panel (Sec 34)
A Parking lamps
B Coolant levelC Engine oil level
D Door closureE Brake fluid level
F Disc pad wearFig. 9.14 Location of control units (Sec 33)
A Digiplex ignition system control unit
B Fuel cut-out valve control unit