1983 FIAT UNO wiring diagram

REPAIRS & OVERHAUL
Engine and Associated Systems
Engine (also see Chapter 13)Page 1•1
Cooling and heating systems (also see Chapter 13)Page2•1
Fuel system (also see Chapter 13)Page 3•1
Ignition system (also see Chapter 13)Page4•1
Transmission
Clutch (also see Chapter 13)Page5•1
Transmission (also see Chapter 13)Page6•1
Driveshafts, hubs, roadwheels and tyres (also see Chapter 13)Page7•1
Brakes
Braking system(also see Chapter 13)Page 8•1
Electrical
Electrical system(also see Chapter 13)Page 9•1
Steering and suspension
SteeringPage 10•1
Suspension (also see Chapter 13)Page 11•1
Bodywork
Bodywork (also see Chapter 13)Page 12•1
Additional information
Supplement: Revisions and information on later models Page 13•1
Wiring DiagramsPage 14•1
REFERENCE
MOT Test Checks PageREF•1
Tools and Working Facilities Page REF•5
General Repair Procedures Page REF•8
Fault FindingPage REF•9
Buying Spare Parts & Vehicle Identification Numbers PageREF•12
Glossary of Technical Terms PageREF•13
IndexPage REF•17
Contents

pump jet and give ten full strokes of the
throttle lever, pausing between each stroke to
allow fuel to finish dripping.
8The total volume of fuel collected should be
between 2.5 and 4.5 cc. Adjust the nut on the
pump control and if necessary to increase or
decrease the volume of fuel ejected.
Fast idle adjustment
9With the choke valve plate fully closed, the
throttle valve plate should be open to give a
dimension (X) (Fig. 3.18) of between 0.90 and
1.0 mm (0.035 to 0.039 in). Use a twist drill of
suitable diameter to measure the gap. If
necessary, adjust by means of the screw and
locknut.
Anti-flooding device
10Close the choke valve plate by means of
the control lever. At the same time, push the
lean out valve rod towards the valve.
11There should be a gap (X) (Fig. 3.19)
between the edge of the choke valve plateand the carburettor throat of between 4.75
and 5.25 mm (0.187 to 0.207 in). Adjust if
necessary by means of the screw and locknut
on the lean out valve.
11 Carburettors (Weber 32 ICEE/
250 and Solex C32 DISA 14)-
description and adjustment
4
1One of these carburettors is used on
903 cc ES engines. They are very similar to
the Weber 32 ICEV 50/250 and Solex
C32 DISA 11 already described in this
Chapter except that a fuel cut-out solenoid
valve is fitted in association with the Digiplex
ignition system (see Chapters 4 and 9).
2The solenoid valve cuts off the supply of
fuel to the carburettor whenever the
accelerator pedal is released during overrun
conditions.
3A fuel cut-out device control unit receives
information regarding engine speed from the
static ignition control unit.
4A throttle butterfly switch relays informationthat the accelerator pedal is in the released
state.
5At certain minimum idle speeds during
deceleration, the fuel cut-out solenoid valve is
re-energised so that engine idling is
maintained without the tendency to cut out.
6The Solex type control unit varies the fuel
cut-out point according to the deceleration
value.Fault testing
7Should a fault develop, connect a test lamp
between the fuel cut-out solenoid switch and
a good earth.
8Connect a reliable tachometer to the engine
in accordance with the maker’s instructions.
9Start the engine and raise its speed to
between 3000 and 4000 rev/min, then fully
release the accelerator pedal.
10The test lamp should only go out during
the period when the accelerator pedal is
released. Should the test lamp remain on all
the time, or never come on, check the throttle
switch earth and the solenoid switch
connections.
11Disconnect the multi-plug from the control
unit. Switch on the ignition and check that a
test lamp connected between contact 7 of the
multi-plug and earth will illuminate. If it does
not, there is an open circuit from connection
15/54 of the fuel cut-off switch.
12Switch off the ignition and check for
continuity between contact 3 of the multiplug
and earth. An ohmmeter will be required for
this test.
13If there is no continuity (ohmmeter shows
infinity), check all the system earth
connections. Also check that the wiring plug
under the control unit is properly connected.
14Finally, check the engine speed signal. To
do this, a tachometer must be connected to
the single socket under the control unit within
the engine compartment.
15If the tachometer registers correctly then
this confirms that the electronic ignition
Fuel system 3•9
Fig. 3.18 Fast idle adjustment diagram (Solex C32 DISA 11)
(Sec 10)
X = 0.90 to 1.0 mm (0.035 to 0.039 in)Fig. 3.19 Anti-flooding device adjustment diagram
(Solex C32 DISA 11) (Sec 10)
X = 4.75 to 5.25 mm (0.187 to 0.207 in)
Fig. 3.21 Sectional view of fuel cut-off
switch (Solex C32 DISA 14) (Sec 11)
Fig. 3.20 Moving lean out valve rod
(Solex C32 DISA 11) (Sec 10)
X = 4.75 to 5.25 mm (0.187 to 0.207 in)
3

Idle speed and mixture
adjustment¢
29Before carrying out any adjustments, the
engine must be at operating temperature, the
fan having cut in at second speed and then
switched off.
30Release the locknut and turn the main idle
speed screw in the throttle valve housing until
the engine idles at the specified speed. This
should be all that is necessary to obtain the
correct idle speed, as the throttle valve plate
base setting is set during production.
However, if wear has taken place, or incorrect
adjustment has been carried out previously,
proceed in the following way.
31Disconnect the intake duct from the
throttle valve housing. Release the locknut on
the base (small) adjusting screw, and turn thescrew until there is a clearance between the
lower edge of the throttle valve plate and the
throat wall of between 0.05 and 0.1 mm
(photos).
32With the engine still at operating
temperature, start the engine, and having
released the locknut, turn the main (large) idle
speed screw fully clockwise to close the
bypass passage.
33Now turn the base (small) screw until the
engine idles at between 700 and 800 rpm.
Tighten the locknut.
34Finally, turn the main (large) adjusting
screw to give an idle speed of between 800
and 900 rpm.
35It is unlikely that the mixture will require
alteration, but if it does, connect an exhaust
gas analyser to the car in accordance with the
equipment manufacturer’s instructions.
36With the engine at operating temperature,
prise out the tamperproof cap, and turn the
mixture screw, which is located in the airflow
meter, until the CO level is as given in the
Specifications. Turning the screw clockwise
richens the mixture, turning it anti-clockwise
weakens the mixture. Use a close-fitting Allen
key for the adjustment (photo).
Fuel injection system -
electrical testsª
37When carrying out checks to trace a fault
in the system, an ohmmeter should be used
for the following tests.
38Disconnect the multipin connector from
the ECU, and also the one from the system
control relay, and apply the probes of the
ohmmeter in accordance with the following
sequence to check for continuity in thecables. The component wiring plug will of
course be disconnected for the test.
ECU connector Component connector
plug terminal plug terminal
1 1 of ignition coil
2 2 of throttle position
switch
3 3 of throttle position
switch
4 50 of ignition switch
5 Earth
5 5 of airflow meter
7 7 of airflow meter
8 8 of airflow meter
9 9 of airflow meter
9 9 of throttle position
switch
9 18 of supplementary air
valve
9 87 main relay socket
10 10 of coolant temperature
sensor
12 Injector terminals
13 Earth
System control Component connector
relay connector plug terminal
plug terminal
1 1 of ignition coil
15 15 of ignition switch
30 Battery positive
31 Earth
50 50 of ignition switch
87 Injector terminals
87 18 of throttle position
switch
87 9 of ECU multipin socket
87b Fuel pump (fused)
13•68 Supplement: Revisions and information on later models
Fig. 13.42 ECU and component connector plug terminals - 1301 cc Turbo ie engine (Sec 9C)
For colour code see main wiring diagrams
9C.31C Checking throttle valve plate
opening with a feeler blade
9C.36 Using an Allen key to adjust the
mixture (CO level)
9C.31B Idle speed base setting screw (1)
and main adjustment screw (2)9C.31A Disconnecting the throttle valve
housing intake duct9C.27B Removing the air cleaner element

13•88 Supplement: Revisions and information on later models
Fig. 13.73 Wiring diagram of the Microplex ignition system on the 1301 cc Turbo ie
engine (Sec 10)Fig. 13.74 Wiring diagram of the Microplex ignition system on the 1372 cc Turbo ie
engine (Sec 10)1 ECU
2 Safety pressure switch
3 Ignition unit with coil
4 Distributor
5 Anti-knock sensor
6 Vacuum/pressure pick-up in engine inlet
manifold
7 Socket for diagnostic equipment8 Tachometer
9 Spark plugs
10 Switch to earth (to retard advance
curve if necessary)
11 Turbocharger operation warning light
12 Anti-theft relay (where fitted)
13 Hidden anti-theft switch (where fitted)1 ECU
2 Pipe (pressure/vacuum
in inlet manifold to
control unit)
3 Spark plug
4 Distributor
5 Ignition coil (with
control unit)6 Tachometer
7 Ignition switch
8 Connector
9 TDC sensor
10 Engine speed
11 Anti-knock sensor
12 Air pressure safety
switch13 Speedometer signal
for electronic injection
14 Connector
15 Diagnostic socket
a Crankshaft pulley
b Flywheel

TDC sensor
48Insert the probes of the ohmmeter
between terminals 1 and 2 of the multipin
connector; 618 to 748 ohms (1301 cc) or 578
to 782 ohms (1372 cc) should be indicated.
49If necessary, carry out a check of the gap
between the sensor and the crankshaft pulley,
as described in Chapter 4, Section 10.
ECU supply
50Switch on the ignition, and then insert the
probes of a voltmeter between terminals 13
and 11 of the multipin connector. Battery
voltage should be indicated. If not, check the
battery earth, ignition switch or intermediate
connector plug for security.
Power module supply (1301 cc)
51Pull the multipin plug from the powermodule, and connect the probes of a
voltmeter between terminal 4 of the connector
and earth. If the reading is less than battery
voltage, check the security of all connections
between the ignition switch and terminal + 15
of the ignition coil.
52Reconnect the multipin connector to the
ECU, but have the one from the power
module disconnected, and then switch on the
ignition.
53Connect the voltmeter between terminals
4 and 2 of the power module multipin
connector. If the indicated voltage is less than
battery voltage, check the security of all
connections between the ignition switch and
terminal + 15 of the ignition coil, and the
battery earth. If all are satisfactory, check for
continuity between terminals 11 and 12. If
continuity is broken, renew the ECU.
Power module (1372 cc)
54Proceed as described in paragraph 53.
Anti-knock sensor
55If “pinking” occurs, or loss of power is
noticed, test the sensor by substitution of a
new one.
Ignition coil
56Disconnect the leads from terminals 1
and 15 on the coil before testing.
57Using the ohmmeter, check the resistance
of the primary winding. This should be
between 0.31 and 0.37 ohms (1301 cc) or
0.40 to 0.49 ohms (1372 cc), at an ambient
temperature of 20ºC (68ºF).
58The secondary winding resistance should
be between 3330 and 4070 ohms (1301 cc) or
4320 to 5280 ohms (1372 cc), at an ambient
temperature of 20ºC (68ºF).
Distributor
59Check the resistance of the rotor arm,
which should be between 800 and
1200 ohms.
60Where all the foregoing tests have proved
satisfactory, then any problem must be due to
a fault in either the power module or the ECU.
These components can only be checked by
the substitution of a new unit - power module
first, then the ECU.
Safety pressure switch
61The device protects the engine from
excessive turbocharging pressure, cutting off
the ignition by earthing the Microplex ECU.
Testing is not possible without a special
pressure pump, so the easiest way to check a
suspected fault is to fit a new unit.
Digiplex 2 ignition system -
description
62This system operates in a similar manner
to that of the earlier type described in Chap-
ter 4, but the circuit layout differs to suit the
Mono Jetronic fuel injection system. In
operation, the main difference is that the
Digiplex 2 system has a greater number of
13•90 Supplement: Revisions and information on later models
Fig. 13.81 Microplex ignition system
control unit connection (Sec 10)
For colour code, see main wiring diagramsFig. 13.80 Microplex ignition system ECU multipin connector (Sec 10)
For colour code, see main wiring diagrams
Fig. 13.79 Ignition advance curves - Microplex ignition system on the 1301 cc Turbo ie
(Sec 10)

Auxiliary control panel
(later models) -
removal and refitting
Á
61Disconnect the battery negative lead.
62Insert the flat of a screwdriver under the
trim piece at the end of the auxiliary panel as
shown and prise it free. Repeat the procedure
and remove the trim piece at the other end of
the panel (photo).
63Undo the retaining screws, withdraw the
panel from the facia. Disconnect the wiring
connectors from the panel switches to
remove the panel completely (photo).
64A switch bulb can be renewed by
untwisting the holder and removing the holder
and bulb.
65A switch unit can be removed from the
panel by unscrewing the four retaining screws.66Refitting is a reversal of the removal
procedure. Ensure that the wiring connections
are securely made and check for satisfactory
operation of the switches on completion.
Heater control panel
(later models) -
removal and refitting
Á
67Disconnect the battery negative lead.
68Pull free the heater/fresh air and blower
control knobs (photo).
69Undo the two retaining screws and
withdraw the control panel from the facia
(photos). Detach the wiring connectors from the
panel illumination lights and remove the panel.
70Refitting is a reversal of the removal
procedure. Ensure that the wiring connections
are securely made and on completion check
that the operation of the controls is satisfactory.
Trip master Á
71This electronic instrument is fitted into the
check panel of 1100SL and 1300SL models
from 1986.
72The device provides information on fuel
consumption, range, speed and elapsed time.
73With the ignition key turned to MAR,
figures are displayed in respect of the last
journey - average fuel consumption, average
speed and elapsed time (up to switching off
the ignition).
74As soon as the engine is started, the
instrument processes the current values to
include fuel consumption, range and the
actual time. 75Fuel consumption is only displayed when
the road speed exceeds 8.0 km/h (5.0 mph).
76The fuel range is only displayed after a
road speed of between 25.0 and 70.0 km/h
(15.0 to 44.0 mph) has been maintained for at
least 90 seconds or at higher speeds for
22 seconds.
77A reset button is provided, also a display
change button (from instant to average or
total values). Should the instrument reading
exceed 99 hours, 59 minutes or 1000 km
(622 miles) depressing the display change
button will display all zeros. Depress button E
to resume normal function.
78Refer to the end of the manual for a wiring
diagram of the check panel, incorporating the
trip master.
Interior roof mounted spotlamp,
switch and/or clock -
removal and refitting
Á
79Disconnect the battery negative lead.
80Prise free the lamp unit from its aperture
in the roof panel using a thin-bladed
screwdriver. The lamp bulb can be inspected
by untwisting the holder and withdrawing it
from the rear of the unit (photos). Extract the
bulb from the holder if it requires renewal.
81To remove the lamp switch from the
panel, reach through the lamp aperture and
press it free from the roof panel (photo).
Detach the wiring connectors.
82To remove the clock, reach through the
lamp aperture and undo the retaining screws
(photo). Withdraw the clock and detach the
wiring connectors.
13•108 Supplement: Revisions and information on later models
15.69B . . . and withdraw the heater control
panel15.69A . . . undo the retaining screws
(arrowed)15.68 Remove the control knobs . . .
15.63 . . . and withdraw the auxiliary
control panel
15.62 Prise free the trim covers for access
to retaining screws . . .15.59B . . . and disconnect the
speedometer cable15.59A . . . withdraw the instrument
panel . . .

Wiring diagrams 14•1
14
Component key for wiring diagrams 1 to 29
Note: Not all the items listed will be fitted to all models
No Description
00200 Alternator with built-in regulator
00500 Battery
01001 Starter motor
01202 Rear front electric window motor
01203 Left front electric window motor
01206 Windscreen wiper motor
01207 Rear screen wiper motor
01252 Right front door locking motor
01253 Left front door locking motor
01254 Right rear door locking motor
01255 Left rear door locking motor
01400 Windscreen washer pump
01401 Rear screen washer pump
01420 Electric fuel pump
01500 Engine cooling fan
01502 Injector cooling fan
01504 Ventilation fan
02001 Engine cut-out solenoid on injection pump
02010 Fuel injector
02011 Fuel injector
02012 Fuel injector
02013 Fuel injector
02015 Supplementary air valve
02210 Accelerator pump outlet cut-out solenoid on
carburettor
02215 Supplementary air valve
02400 Ignition coil
02405 Ignition coil with electronic control unit
02490 Static advance ignition control unit
02492 Microplex ignition system control unit
03000 Insufficient engine oil pressure switch
03002 Right front door ajar switch
03003 Left front door ajar switch
03004 Right rear door ajar switch
03005 Left rear door ajar switch
03006 Handbrake ‘on’ warning switch
03007 Brake stop-lamp switch
03008 Reversing light switch
03028 Radiator thermostatic switch
03029 Coolant overheating warning light thermostatic switch
03034 Injector cooling fan thermostatic switch
03035 Accelerator pump outlet cut-out solenoid thermostatic
switch
03036 Radiator thermostatic switch with two operating ranges
03053 Map reading light switch
03059 Foglamps switch
03060 Rear foglamp switch
03110 Heated rear screen switch
03114 Ventilation fan switch
03123 Air pressure switch
03142 Choke warning light switch
03144 Reset switch
03145 Display switch
03305 Right front door open light push button
03306 Left front door open light push button No Description
03319 Horn push button
03500 Ignition switch
03505 Butterfly valve cut-off switch
03506 Throttle position switch
03530 Right front electric window switch
03531 Left front electric window switch
03546 Rear screen wash/wipe switch
03550 Hazard warning lights switch
04010 Steering column switch unit, direction indicators
04022 Steering column switch unit, headlamps, main beam
and dipped, side lights
04032 Steering column switch unit, windscreen wash/wipe
04214 Fuel injection system control relay
04215 Antiskid system failure relay
04225 Radiator fan 2nd speed engagement relay feed
04241 Foglamps relay feed
04260 Electric windows motor relay feed
04283 Antiskid system relay
04291 Horn relay feed
04292 Heated rear screen relay feed
04441 Dim-dip cut-out 04600 Ignition distributor
04700 Coolant temperature sender unit
04701 Electronic injection coolant temperature sender unit
04720 Oil pressure sender unit
05008 Right headlamp, main beam and dipped with side light
05009 Left headlamp, main beam and dipped with side light
05013 Abnormal fuel consumption sensor
05015 Right foglamp
05016 Left foglamp
05410 Right front direction indicator
05411 Left front direction indicator
05412 Right front side direction indicator
05413 Left front side direction indicator
05640 Rear number plate lamp
05690 Right rear light cluster, sidelight, direction indicator,
brake light, rear foglamp
05691 Left rear light cluster; side light, direction indicator,
brake light, rear foglamp
06000 Centre courtesy light
06026 Map reading light
06076 Ideogram fibre optic light
06080 Heater controls light
06084 Instrument panel light
06300 Sidelights warning light
06305 Main beam headlamps warning light
06310 Rear foglamps warning light
06311 Foglamps warning light
06315 Hazard warning lights warning light
06320 Direction indicators warning light
06335 Insufficient brake fluid level warning light
06336 Handbrake ‘on’ warning light
06343 Insufficient engine oil pressure warning light
06344 Insufficient brake fluid level warning light
06345 Fuel reserve warning light
06350 Coolant overheating warning light

14•2 Wiring diagrams
No Description
06355 Battery charging warning light
06365 Choke warning light
06368 Antiskid system failure lamp
06385 Heated rear screen warning light
06800 Horn
06801 Right horn
06802 Left horn
07000 Coolant level sensor
07001 Engine oil level sensor
07003 Brake fluid level sensor
07015 Right front brake pad wear sensor
07016 Left front brake pad wear sensor
07020 Engine speed sensor
07021 TDC sensor
07022 Anti-knock sensor
07023 Diagnostic socket
07037 Butterfly valve (cut-off) switch
07050 Fuel gauge
07051 Instant fuel consumption gauge (econometer)
07052 Airflow meter
07060 Idle cut-off device
07107 Roadwheel speed sensors
07109 Vacuum switch
07191 Absolute pressure sensor
07192 Vacuum switch
07400 Fuel gauge
07410 Engine oil temperature gauge
07415 Coolant temperature gauge
07420 Engine oil pressure gauge
07430 Tachometer
07460 Clock
07461 Digital clockNo Description
08051 Ignition coil condenser
09000 Dim-dip transformer
09008 Radiator cooling fan 1st speed resistor
09100 Heated rear screen
10022 Cut-off device electronic control unit
10500 Control (fuse) box
10515 Electronic injection control unit
10571 Central locking control unit
10584 Antiskid system ECU
10586 Pressure modulators
59000 Cigar lighter
60000 Instrument panel
60204 Four place fusebox
70090 General earth
70091 General earth
70092 Earth plate
M Electronic control unit
Wire colour codes
A Light blue
B White
C Orange
G Yellow
H Grey
L Blue
M Brown
N Black
R Red
S Pink
V Green
Z Violet
Example of two-colour wire: BN (White/Black) Component key for wiring diagrams 1 to 29 (continued)
Note: Not all the items listed will be fitted to all models