The engine control unit
M10 monitors
and controls the UNIJET electronic injection system.
The engine control unit
M10 receives
a supply controlled by the ignition (15/54) to pin 13 of connector
B from the line protected by fuse B25.
The relay
J10 controls the supply
of the system: it is supplied by the battery, the line for maxifuse
UGD of B5, the coil is supplied by the same line
and is energized by an earth signal coming from the control unit M10, from pin 46 of connector C. This energizing makes
it possible to supply pins 7, 8 and 1 of the control unit.
(the line which goes from
J10 to pin 1 is also protected
by fuse B41).
The relay
J15 is also supplied
by the battery, from the line for maxifuse UGD of B5: signals
arrive, from pins 30 and 52 of connector C for the control unit M10, which energize the relay J15, which
provides the supply for the electric fuel pump N40 which is earthed
through the inertia switch I50.
In
case of impact, this cuts off the circuit to prevent the danger
of fuel delivery.
The diesel pre-heating relay
J17,
supplied by the battery - connector A - through the line protected
by fuses B37 and B39, is energized
by the signal coming from the alternator ("recharging"
warning light signal): the pre-heating only operates when the engine
is running.
Under these circumstances, the relay controls
the operation of the diesel heating resistance
O20: the
thermal contact (connector A of O20) deactivates
the system when the heating is over.
The control unit
M15, which manages
the pre-heating of the heater plugs A40, is supplied
- connector A - directly by the battery through the line protected
by fuse B37.
It receives commands from
pins 38 and 51 of connector C of
M10 which controls the timing
and sends a feedback signal o pin 1 of connector B of the control
unit.
Connector B is connected to the heater plugs
A40.
Pins 4 and 5 of connector A of
M10 are
earthed.
The control unit
M10 receives
signals from the various sensors in order to monitor all engine
service conditions.
Rpm sensor
K46 supplies information
on engine speed via a frequency signal sent to pin 26 of connector
D of control unit M10.
It receives
an earth signal from pin 37 of control unit connector D. Both signals
are weak and are therefore suitably shielded by pin 17.
Timing sensor
K47 is supplied
from pin 12 of connector D of control unit M10.
It receives a reference earth from pin 2 of connector D
of control unit
M10 and sends it a signal of frequency
corresponding to the timing of pin 3 of the same connector.
Engine temperature sender unit
K45 eceives
a reference earth from pin 27 of connector D of control unit M10 and supplies a signal proportional to coolant temperature to
pin 36 of the same connector.
Air flow meter
K41 receives a
general power supply from pin 11 of control unit connector D and
a reference voltage from control unit pin 1.
It sends
pin 14 of connector D a signal proportional to air flow.
K41 also
contains an air temperature sensor: the sensor reference earth is
supplied by pin 4 of connector D of M10, while an
air temperature signal is received by pin 23 of connector A.
Accelerator pedal
K55 is fitted
with two built-in potentiometers (a main one and a safety back-up).
The first receives power and earth from pins 5 and
23 respectively of connector C of
M10 and sends a corresponding
signal to pin 10 of the same connector.
The second
receives power and earth from pins 21 and 8 respectively of connector
C of
M10 and sends a corresponding signal to pin 9 of
connector C.
Fuel temperature sensor
K81 fitted
on the return manifold measures the temperature of diesel leaving
the injectors.
It receives a reference earth from pin
1 of connector C of
M10 and sends a fuel temperature
signal to control unit pin 24.
The supercharging sensor
K82 measures
the turbocharger pressure.
It is supplied from pin
8 of conector D of
M10 and receives a reference earth
from control unt pin 7.
The signal is sent to pin 6
of control unit connector D.
Fuel pressure sensor
K83 is responsible
for providing the injection control unit with a feedback signal
for governing pressure and injection duration.
It receives
power and a reference earth from pins 13 and 14 respectively of
connector D of
M10. It then sends a pressure signal to
pin 24 of the same connector.
Fuel pressure regulator
N77 maintains
fuel pressure level constant in the accumulator.
Both
control signals are produced by pins 31 and 21 of control unit connector
D.
EGR solenoid
L30 controls exhaust
gas recirculation.
It is supplied from pin 37 of connector
C of
M10 and sends a signal to control unit pin 50.
Pin 8 of connector B of
M10 receives
the signal coming from the brake lights switch I30,
with the supply controlled by the ignition (INT) from fuse F1 of the junction unit B1
(
See
E2021
BRAKE LIGHTS
).
Pin 2 of connector C of
M10 receives
a signal from the second contact of clutch pedal switch I31, ignition-operated (INT/A) through a line protected by fuse F1 in junction unit B1.
The injectors
N70 receive the
opening go ahead supply from pins 2 (cylinders 1 and 4) and 4 (cylinders
2 and 3) for connector E of M10.The engine control unit sends commands to
the injectors from pins 9, 7, 5 and 3 of connector E for cylinders
1, 2, 3 and 4, respectively.
The control unit is equipped with a self-diagnostic
unit that may be used by connecting the unit to connector
R10 via pin 28 of connector C.
The autod-diagnostic system also produces
a signal for the "injection failure" warning light: the
instrument panel
E50 receives a supply controlled by
the ignition (INT) from the line protected by fuse F1 in
the junction unit B1: when the earth signal arrives
from pin 48 of connector C, the "injection failure" warning
light comes on.An earth signal to pin 43 of connector C,
on the other hand, lights up the "heater plugs" warning
light.
If the engine temperature is high, the control
unit lights up the warning light in the instrument panel
E50 (signal
from pin 49 of connector C).
The control unit
M10 is connected
with the CODE control unit M20 through the special line
from pin 13 of connector C; in this way, if the CODE control unit
does not detect the correct code, it does not give the go ahead
and the engine cannot be started up.
The speedometer signal (vehicle speed) reaches
pin 26 of connector C of the control unit
M10
(
See
E4021
SPEEDOMETER
).
Control unit M10 is connected to the air
conditioning system via pin 32 of connector D and pin 3 of connector
B. This allows engine idling speed to be adjusted to increased engine
load whenever the compressor is activated, or to turn off the compressor
in the case of high speeds or high engine loads (
See E6021 COMPRESSOR ENGAGEMENT
).
The control unit also controls the engine
cooling system: pin 23 of connector B, pin 15 of connector D and
20, 45 of connector C control activation of the relevant fan (
See E5020 ENGINE COOLING
).