sensor FIAT MAREA 2001 1.G Owner's Guide

Engine
Fuel feed system
JTD Marea-Marea Weekend ©
2000 range ©
10.
iH
ft
B I 0 ] I D
[ 0 0 1 1
D
0 1 GLOW PLUG PREHEATING CONTROL
UNIT
The glow plugs are controlled by means of a
preheating control unit under the direct con­
trol of the injection control unit.
The preheating control unit contains a smart
relay that sends a return response (feedback)
to the injection control unit, which is thus in­
formed of faults in the preheating control unit
or glow plug short-circuits to earth.
The figure shows the connectors on the base
of the preheating control unit and the pin-out
1. Earth
2. Injection control unit (pin 22)
3. Power supply from main injection relay
4. Not connected
5. Injection control unit (pin 62)
8. Positive from battery (+30)
G. Glow plugs (only four outputs are used)
ACCELERATOR
PEDAL POTENTIOMETER
Accelerator pedal position is converted to an
electrical voltage signal and send to the injec­
tion control unit by a potentiometer connected
to the accelerator pedal.
Accelerator pedal position is processed to­
gether with rpm information to provide injec­
tion times and pressure.
The sensor consists of a case (1) secured to
the pedal by a flange, which contains an axi-
ally-positioned shaft (2) connected to two
potentiometers (3): main and safety potenti­
ometers.
A coil spring on the shaft ensures the correct
resistance to pressure while a second spring
ensures return upon release.
16 Publication no. 506.763/24

Marea-Marea Weekend 9 -™ Engine
2000 range (j§) Fuel feed system
10.
I I TEST
4F017XJ01
A switch (1) on the brake pedal con­
trols the car brake lights; the same
switch sends a signal to pin 59 of the
injection control unit
The control unit uses the "brake pedal
depressed" signal to:
- detect a situation of over-run;;
- check the plausibility of the signal
from the accelerator potentiometer
CLUTCH PEDAL SWITCH
A switch (2) on the clutch pedal is connected to pin 61 of the injection control unit.
The injection control unit uses the "brake pedal operated" signal to distinguish gear engaged and gear
shift conditions.
PRESSURE RELIEF SENSOR
The sensor is fitted to the intake manifold and
the signal sent to the injection control unit is
used to:
- regulate injection pressure;
- regulate injection duration.
The figure alongside shows the sensor and
electrical connector with the following pin-
out:
1. pressure signal
2. Earth
3. Fuel feed system
ATMOSPHERIC PRESSURE SENSOR
The atmospheric pressure signal is built into the injection control unit. It is responsible for measuring at­
mospheric pressure in order to correct measured air flow and reference air flow values to control the EGR
function.
Copyright by Fiat Auto 17

Engine
Fuel feed system
JTD Marea- Marea Weekend 0
2000 range ©
10.
FUEL SUPPLY CIRCUIT
Operationally-speaking, the fuel supply circuit is divided into a low pressure circuit and a high pressure
circuit.
The low pressure circuit consists of a tank, multifunction valve, auxiliary fuel pump submerged in the tank
and a return manifold.
The high pressure circuit consists of a radialjet pressure pump, delivery manifold and injectors.
1. Fuel tank
2. Submerged fuel pump (auxiliary) with fuel
level gauge control
3. Multifunction valve
4. Pressure pump control pulley
5. Diesel filter cartridge
6. Pressure pump
7. High pressure pipe
8. Delivery manifold (rail)
9. Injectors
10. Fuel recirculation pipe (injector return)
11. Return manifold
12. Pressure regulator
13. Fuel temperature sensor
14. Fuel pressure sensor
15. Diesel heater
16. Fuel temperature sensor
17. Sensor indicating presence of water in fuel
filter
18 Publication no. 506.763/24

Marea- Marea Weekend 9 ™
2000 range (Q)
4F019XJ01
1. Impeller
2. Volumes
3. Intake port
4. Outlet port
5. Rollers
6. Outer race
7. Pressure relief valve
4F019XJ02
Engine
Fuel feed system
10.
SUBMERGED FUEL PUMP ASSEMBLY
(AUXILIARY) AND LEVEL GAUGE CON­
TROL
The assembly consists mainly of:
- a roller-type fuel pump;
- a fuel level gauge;
- a fuel filter
The submerged fuel pump is volumetric type
with rollers and a motor with brushes and
permanent magnet excitation.
Impeller (1) is driven by the electric motor to
turn and create volumes (2) that move from
intake port (3) to outlet port (4).
These volumes are delimited by rollers (5) that
adhere to outer race(6) as the motor turns.
The pump is fitted with two valves: a check
valve to prevent the fuel circuit emptying
(with the pump off); a second pressure relief
valve (7) that short-circuits the outlet to the
inlet when pressures exceed 5 bars.
FUEL FILTER
The fuel filter is located in the engine bay.
The filter is cartridge type with a filter element
(1) made up of a pack of paper discs with a
filtering area of some 5300 cm 2 and a filter
gauge of 4 - 5 microns.
The filter is equipped with a fuel preheating
device (2) controlled by the engine control
unit via a relay.
The control unit activates or deactivates the
diesel filter on the basis of a diesel tempera­
ture signal sent by sensor (3) on the filter.
A plug (4) screwed to the base of the fuel
filter cartridge is used to drai off the water.
The plug incorporates a sensor for the detec­
tion of water in the diesel filter connected to a
warning light on the instrument panel.
1. Filter cartridge
2. Diesel preheating device
3. Diesel temperature sensor
4. Water drain plug with sensor to detect
presence of water in diesel filter
Copyright by Fiat Auto 19

Marea- Marea Weekend <§l ™
2000 range ©
Engine
Fuel feed system
TZZZZZZZZZZZZZZZZZZb
TZZZZZZZZZZZZZZ*
10.
MULTIFUNCTION VALVE
The multifunction valve is located on the fuel
tank and performs the following functions:
- tank pressurisation
- ventilation
- seal if the car rolls over
Tank pressurisation
Tank pressurisation is maintained at a level be­
tween 55 and 75 mbars by means of a valve
mounted on a sealing rim.
The valve is supported by a steel plate and held in place by a spring.
When tank pressure exceeds a specified level, it overcomes spring resistance and allows the valve to rise
so that vapours can flow out.
When the pressure returns to within specified limits, the valve closes again
Ventilation
Under certain car service conditions, a vacuum may build up in the tank due to the effect of:
- heat changes;
- fuel consumption
in this case, the valve's function is to make up pressure inside the tank by letting air into the tank.
If this function is not performed correctly, the car may judder or stall due to difficulties in supplying the
pump.
Seal if the car rolls over
The roll-over function prevents fuel emerging from the tank if the car rolls over or tilts to a great extent.
During normal car operation (bends, acceleration, braking etc.), the fuel slops about and may emerge.
The highly-sensitive roll-over valve prevents this happening.
DELIVERY MANIFOLD (RAIL)
The delivery manifold (rail) is fitted to the cylinder head on the intake side.
Its volume damps fuel pressure fluctuations due mainly to:
- operation of the pressure pump;
- injector opening.
A fuel pressure sensor is fitted in the middle of the delivery manifold.
Hydraulic connections (high pressure) are via special steel pipes.
Copyright by Fiat Auto 21

Engine
Fuel feed system
Marea- Marea Weekend W)JTD
2000 range ©
INERTIA SAFETY SWITCH
To increase car occupant safety in the case of
impact, the car is fitted with an inertia switch
located inside the passenger compartment se­
cured to the inside of the left panel.
This sensor reduces the possibility of fire (due
to emerging fuel) by deactivating the auxiliary
fuel pump that supplies the injection circuit.
The switch consists of a steel ball, fitted in a
tapered housing, kept in place by the attrac­
tion force of a permanent magnet.
In the case of violent impact, the ball is released from the magnetic detent and opens the normally closed
(NC) electrical circuit to cut off the auxiliary fuel pump connection to earth, and as a consequence the
supply to the injection system.
To restore the auxiliary pump earth connection, move back the seat and press the switch until a click is
heard.
Even after an apparently slight impact, if there is a smell of fuel or there are leaks from the fuel
system, do not turn the switch back on, but search for the fault and remedy it to prevent the risk
of fire.
'N.C. N.A. C
Inertia switch components
1. Inertia switch assembly
2. Sheath
3. Button
4. Upper side
5. Engagement side
6. Permanent magnet
7. Permanent magnet seat
8. Steel ball
C Common terminal
N.C. Normally closed contact
N.A. Normally open contact
22 Publication no. 506.763/24

Engine
Fuel feed system
JTD Marea-Marea Weekend 9
2000 range ©
E.G.R.
TOR
VALVE SELF-ADJUSTMENT MO-
Removing-refitting
- Disconnect the negative battery lead, then
remove the sound insulation shield follow­
ing the instructions in the previous para­
graphs.
1. Disconnect the electrical connection (1),
then loosen the bolts fixing the E.G.R.
valve self-adjustment motor and remove it.
E.G.R. VALVE HEAT EXCHANGER
Removi ng - ref itti ng
- Remove the throttle casing and the E.G.R.
valve following the instructions in the pre­
vious paragraphs.
2. Remove the hose connecting the throttle
casing to the intercooler.
- Drain the engine coolant.
3. Disconnect the pipes shown in the figure
from the thermostat, acting on the retaining
bands, then disconnect the electrical con­
nection (1) for the engine coolant tem­
perature sensor.
4. Undo the bolts fixing the heat exchanger
pipe to the exhaust manifold.
32 0"" Und«r 4 Print n° 506.763/25

Engine
Fuel feed system
Marea- Marea Weekend 9 ™
2000 range ©
SOLENOID VALVE ON VACUUM RES­
ERVOIR FOR THROTTLE CASING
PNEUMATIC VALVE
Removing-refitting
- Disconnect the negative battery lead, then
remove the sound insulation shield follow­
ing the instructions in the previous para­
graphs.
1. Disconnect the electrical connections (1)
at the fuel filter and the supply and return
pipes (2) at the reservoir and the supply
pipe to the pump, then loosen the nuts (3)
fixing the fuel filter mounting. Lift up the
filter and disconnect the electrical connec­
tion (4) for the water in the diesel sensor.
- Release the power assisted steering fluid
supply pipe from the reservoir to the pump
from the retaining band.
2. Disconnect the pipe (1) connected to the
vacuum reservoir and the pipe (2) con­
nected to the vacuum intake pipe from the
solenoid valve. Disconnect the electrical
connector (3), then undo the fixing bolts
(4) and remove the solenoid valve.
VACUUM RESERVOIR
Removing-refitting
- Disconnect the negative battery lead, then
remove the sound insulation shield and the
fuel filter, following the instructions in the
previous paragraphs.
- Release the power assisted steering fluid
supply pipe from the reservoir to the pump
from the retaining band.
3. Disconnect the pipe (1) connected to the
vacuum reservoir and the pipe (2) con­
nected to the vacuum intake pipe from the
solenoid valve. Disconnect the electrical
connector (3), then undo the fixing bolts
(4) and remove the bracket, complete with
solenoid valve, for the throttle casing
pneumatic valve.
34 VI-01 Update IN Print n° 506.763/25

Ma tea- Marea Weekend 9 m
2000 range ©)
Engine
Fuel feed system
10.
1. Undo the fixing nuts (1) and remove the
vacuum reservoir.
SOLENOID VALVE CONTROLLING
SUPERCHARGING PRESSURE
Removing-refitting
- Position the vehicle on a lift, then discon­
nect the negative battery lead.
2. Working from underneath the vehicle, dis­
connect the electrical connector (1) and
the pipes (2).
3. Press the retaining tab on the rear of the
mounting bracket and release the solenoid
valve.
FUEL FILTER
Removing-refitting
4. Disconnect the electrical connections (1)
from the fuel filter and the supply and re­
turn pipes to the tank and the supply pipes
to the pump (2), then undo the nuts (3)
fixing the fuel filter mounting. Lift up the
filter and disconnect the electrical connec­
tion (4) for the water in the diesel sensor.
Copyright by Fiat Auto oi upjdin 35

Electrical equipment
Component location
Marea- Marea Weekend
2000 range ©
55.
AIR BAG WITH SIDE BAG AND PRETENSIONERS AND FAILURE WARNING LIGHT
Component key
3 Power fusebox
4 Junction unit
6 Instrument panel
10 Engine battery earth
11 Battery
12 Ignition switch
70 Connection between dashboard/front ca­
bles
114 Air bag electronic contol unit
115 Passenger's Air Bag
116 Driver's Air Bag
117 Airbag/facia lead connections
231 Clock spring connector
239 Air Bag/left pretensioner cables connection
240 Air Bag/right pretensioner cables connec­
tion
241 Left pretensioner
242 Right pretensioner
352 Left side bag connection
353 Right side bag connection
354 Air Bag earth
355 Pretensioners connection
356 Left side bag sensor
357 Right side bag sensor
358 Left side bag
359 Right side bag
375 Standardized diagnostic socket
3D Power fusebox
R n.d.
R n.d.
Cn.d.*
RG 117'
LR 28C V n.d.
117 Connection between Air Bag/dashboard cables
* RG 3D
356 Left side bag sensor
' ZB 355
' RN 355
358 Left side bag
HR 360'
The cables involved in the wiring diagram are marked with an asterisk.
44 Print n° 506.763/23