time FIAT MAREA 2001 1.G Workshop Manual
Page 75 of 330
Marea- Marea Weekend •
2000 range ©
16v Engine
Fuel feed system
10.
1. Loosen the belt tension using the lock nut
(2) and the adjustment screw (1); then re
lease the belt from the pulley.
2. Undo the bolts fixing the bracket for the
power assisted steering pump mounting
and detach the pump.
3. Undo the nuts fixing the exhaust manifold
to the cylinder head and detach the mani
fold.
- To refit, reverse the order of the operations
carried out for the removal; tension the
power assisted steering pump drive belt,
using the adjustment screw; use tool
189576200 to check that the tension is
between 32 and 45 daN.
ELECTRIC FUEL PUMP WITH LEVEL
SENDER UNIT
Removing-refitting
- Disconnect the negative battery terminal.
- Lift up the lining in the luggage compart
ment and remove the fuel pup protective
cover.
- Disconnect the electrical connection for the
electric pump assembly and the fuel supply
and breather pipes.
4. Undo the ring nut fixing the electric fuel
pump to the tank using tool 1870736000.
The gasket on the tank housing should be
replaced each time the pump drip tray is
removed-refitted.
NOTE The position of the fuel pump is fixed
and is established by a reference in
the housing in the tank which sou Id
correspond to the projection on the
pump drip tray.
Copyright by Fiat Auto 7
Page 89 of 330
Ma tea- Marea Weekend 9 ™
2000 range (Q) Fuel feed system
Engine
10.
Control of injected fuel quantity
The control unit controls the fuel pressure regulator and injectors on the basis of output signals from the
accelerator pedal potentiometer, flow meter and rpm sensor.
The timing and thus the injection sequence are determined when the engine is started up using signals
from the rpm and timing sensor (synchronisation stage); injection timing is then implemented using the
rpm sensor signal alone and considering a injection sequence of 1 -3-4-2.
The control unit inhibits injection in the following cases:
- fuel pressure level greater than 1500 bars;
- fuel pressure level lower than 120 bars;
- engine speed higher than 6000 rpm.
When the engine has warmed up, maximum injection duration (injector opening time) is 1500 ns, but it
can reach 3000 ns during the start-up stage.
Control of injection advance
The electronic control unit determines injection advance mainly on the basis of the quantity of fuel to be
injected.
The injection advance is then corrected on the basis of coolant temperature and speed in order to com
pensate for ignition delays due to low temperatures in the combustion chamber during warm-up.
The optimum injection point is also processed to ensure driving comfort and emission limits laid down by
Euro 3 legislation.
Control of injection pressure
This control is of particular importance because injection pressure influences the following parameters:
- amount of fuel taken into the cylinders for the same injection time duration;
- injected fuel nebulation;
- spray penetration;
- lag between electrical control to injection and actual injection start and end times.
The above parameters engine behaviour significantly, particularly in terms of power output, exhaust emis
sions, noise levels and handling.
The injection control unit controls the pressure governor on the basis of engine load to obtain an optimal
line pressure at all times.
When the engine is cold, injection pressure is corrected on the basis of engine speed and engine coolant
temperature to meet engine needs at different operating temperatures.
Control of auxiliary fuel pump
The auxiliary fuel pump submerged in the tank is supplied by the injection control unit by means of a relay
when the ignition key is turned on.
Fuel supply to the pump is inhibited when one of the following condition occurs:
- when the ignition has been turned on for a certain length of time without the engine running;
- if the inertia switch cuts in.
Control of injection during over-run (cut-off)
The fuel cut-off strategy is implemented when the injection control unit receives information that the ac
celerator pedal has been released from the potentiometer.
Under these conditions, the control unit cuts off the fuel supply to the injectors and restores it before idle
speed is reached.
Copyright by Fiat Auto 3
Page 90 of 330
Fuel feed system
Engine Marea- Marea Weekend 9 ™
2000 range (Q)
10.
Control of idle speed
On the basis of signals from the rpm sensor and engine coolant temperature sensor, the injection control
unit controls the pressure governor and alters the injector control times to maintain idle speed stable at all
times.
Under certain conditions, the idle speed control unit also considers battery voltage.
Control of maximum speed limitation
According to rpm level, the injection control unit limits maximum speed by means of two types of inter
vention:
- as maximum speed approaches, it reduces the amount of fuel injected to reduce line pressure;
- when maximum speed is exceeded, it inhibits operation of the auxiliary pump and injectors.
Control of maximum torque limitation
On the basis of rpm level, the injection control unit computes limit torque and maximum permitted fume
index parameters on the basis of predefined, stored maps.
It then corrects the above parameters using engine coolant temperature and car speed data. The resulting
values are then used to modulate the amount of fuel to be injected by adjusting the pressure regulator and
injectors.
Control of fuel temperature
The injection control uint is kept constantly informed of fuel temperature by a sensor on the return mani
fold.
If fuel temperature exceeds a set value (about 110 °C), the control unit reduces line pressure by adjusting
the pressure governor, leaving injection times unaltered.
Control of coolant temperature
The injection control unit is constantly informed of coolant temperature by a sensor on the thermostat.
If engine coolant temperature or air conditioning fluid pressure exceeds certain levels, the control unit
performs the following actions:
- It reduces the amount of fuel injected by adjusting the pressure governor and injectors (power reduc
tion);
- it controls the engine radiator cooling fan.
Control of glow plugs
The injection control unit controls operation of the glow plug preheating control unit to bring the tem
perature in the combution chambers up to levels that promote fuel self-ignition and thus make start-up
easier.
The control unit controls the operation of the glow plug control unit for a certain time both before (pre
heating) and after (postheating) engine start-up and also controls activation of the warning light on the
control panel.
Preheating, postheating and glow plug warning light activation times vary according to engine coolant
temperature.
4 Publication no. 506.763/24
Page 91 of 330
Marea-Marea Weekend 9]
2000 range (j§)
I) JTD
Fuel feed system
Engine
10.
Exhaust fumes control
Through this function the injection control unit limits any exhaust fumes that could be produced during
transition speeds.
To satisy these requirements the control unit processes the signals supplied by the accelerator pedal po
tentiometer, the rpm sensor and the air flow meter and controls the fuel pressure regulator and the injec
tors to meter the correct amount of fuel to inject.
Exhaust gas recirculation control
On the basis of the signals supplied by the rpm sensor, intake air quantity sensor, engine coolant tempe
rature sensor and accelerator pedal position sensor, the control unit calculates the operating times for the
EGR valve so that the exhaust gases are partly recirculated in certain engine operating conditions in line
with Euro 3 pollution control standards.
Air conditioning system engagement control
The injection control unit manages the operation of the air conditioning system compressor electro
magnet coupling following a logic aimed at preventing operating conditions that would adversely affect
engine performance.
- When the compressor is switched on the injection control unit increases the quantity of fuel during
idling to allow the engine to adjust to the increased power requirements and momentarily interrupts the
supply to the compressor in high engine power requirement conditions (strong acceleration).
Engine immobilizer function control
The system is equipped with an engine immobilizer function. This function is achieved through the pre
sence of a specific control unit (Fiat CODE), capable of conversing with the injection control unit and an
electronic key with a special transmitter for sending a recognition code.
Each time the key is turned to the OFF position, the Fiat CODE system completely deactivates the injecti
on control unit.
When the key is turned to the ON position the following operations take place, in order:
1. the injection control unit (whose memory contains a secret code) sends the Fiat CODE control unit a
request to send the secret code to deactivate the immobilizer functions;
2. the Fiat CODE control unit responds by only sending the secret code after, in turn, having received the
recognition code transmitted by the ignition key;
3. the recognition of the secret code allows the deactivation of the injection control unit immobilizer func
tion and its normal operation.
Autodiagnosis
The complete electronic fault diagnosis of the injection system is carried out by connecting the special
equipment (EXAMINER or EXAMINER PLUS) to the standardized diagnostic socket (EOBD).
The system is also equipped with a self-diagnostic function which recognizes, memorizes and signals any
faults.
If a fault is detected in the sensors or actuators, the recovery strategy is immediately activated in order to
ensure that the engine functions at an acceptable level. The vehicle can be driven to a service centre for
the appropriate repairs to be carried out.
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Page 92 of 330
Fuel feed system
Engine Marea- Marea Weekend © ™
2000 range @
10.
The control unit autodiagnostic system checks the signals coming from the sensors and compares them
with the figures allowed:
- signalling faults during starting
- warning light on for 4 seconds indicates test stage
- warning light off after 4 seconds indicates no fault with components that could alter the pollution con
trol standard figures
- warning light on after 4 seconds indicates fault.
- signalling faults during operation
- warning light on indicates fault
- warning light off indicates no fault with components that could alter the pollution control standard fig
ures.
- recovery
- from time to time, the control unit defines the type of recovery according to the components which are
faulty
- the recovery parameters are managed by components which are not faulty.
Control of cylinder balancing during idling
According to the signals coming from the sensors, the injection control unit controls the idle speed torque,
altering the injector operating times.
Control of irregular operation
Depending on the signals coming from the sensors, the injection control unit corrects the amount of fuel
to be injected in order to improve driveability and reduce jerking whilst driving.
The correction is achieved through the fuel pressure regulator and by varying the injector operating times.
Control of electrical balance
According to the battery voltage, the injection control unit alters the idle speed, to guarantee a sufficient
current supply from the alternator in situations where the consumers are absorbing a great deal of power.
The variation in the idle speed is achived by regulating the fuel pressure and altering the injector operat
ing times.
VGT variable geometry turbocharger control (1910 JTD 110 CV)
The injection control unit processes the signal coming from the supercharging sensor, at the various en
gine operating speeds, and determines the quantity of fuel to be injected, acting on the fuel pressure
regulator and the injector opening times.
In addition, through the solenoid valve, the control unit regulates the geometry of the turbine in order to
ensure optimum performance in all operating conditions.
Turbocharger waste gate valve control (1910 JTD 100 CV)
At the various engine operating speeds, the injection control unit processes the signal coming from the
supercharging sensor and determines the amount of fuel to inject, acting on the fuel pressure regulator
and the injector opening times.
In addition, the control unit controls the opening of the turbocharger waste gate valve, via the solenoid
valve, in order to ensure excellent performance in all operating conditions.
Control of throttle closing when engine is switched off
When the engine is switched off (ignition key in OFF position) the injection control unit closes the throt
tle valve located on the air intake duct via the special solenoid valve.
This action makes it possible to limit the tiresome shuddering of the engine whilst it is switching off.
6 .i. V!-01-.Cancelftand replaces Print n° 506.763/25
Page 102 of 330
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 <fi=2 1 1 15J
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
Page 123 of 330
Marea-Marea Weekend H nD Engine
2000 range (Q) Fuel feed system
10.
1. Grip the outer casing of the regulator, partly
extract it and, at the same time, rotate it so
that the fins (1) which contain the open
ings for the fixing bolts are positioned hori
zontally.
NOTA Do not grip the pressure regulator by
the electrical connector.
Insert the blades of two screwdrivers by the
fins (1) and very carefully extract the pressure
regulator.
NOTE Do not use a screwdriver or other
tools in the seal areas between the
regulator and the pressure pump.
2. Pressure regulator
1. High pressure seal (black or green)
2. Anti-extrusion seal (white)
3. Low pressure seal (black)
NOTE // the high pressure seal accidentally
remains inside the pump casing, turn
the ignition key to the ON position
(engine switched off); this will op
erate the pump shaft and a small
amount of fuel and the seal will come
out.
NOTE Do not, under any circumstances, use any tools for extracting the high pressure seal and this
could damage the inner surface of the pump.
Refitting
- Suction off any impurities present inside the pump casing.
- Check the condition of the three seals and make sure they are correctly positioned before fitting.
- Slightly lubricate the outer surface of the three seals using vaseline. Do not, under any circumstances,
lubricate the other surfaces of the pressure regulator.
- Insert the pressure regulator in its housing on the pump, pressing gently and, at the same time, rotating
the regulator until it is is contact with the surface of the pump.
NOTE Do not, under any circumstances, use a hammer or other tools when fitting the pressure regula
tor.
- Fit the two bolts fixing the pressure regulator to the pump acsing. and tighten them to a torque of
0.9±0.1 daNm.
- Reconnect the electrical connector and complete the refitting of the remaining components reversing the
order of the operations carried out for the removal.
Copyright by Fiat Auto |& yt-01 - Update 37
Page 126 of 330
Marea- Marea Weekend
2000 range ©
Auxiliary Units
Climate control
50
COMPRESSOR ( 1596 engine)
The compressor fitted on this version is the HR V5 variable capacity type, illustrated in the diagram below,
and consists of:
- a crankcase (7) which contains the bores in which the pistons (4) slide;
- an assembly comprising a shaft on which an inclined plate (6) is fitted on which a disc (2) guided by
a pin (5) integral with the five connecting rods (3) controlled by the pistons (4) rotates on roller bear
ings;
- a cylinder head which contains the intake and supply ducts as well as the housing for the regulation
valve (9);
- a plate (8), between the crankcase and the cylinder head, which contains the inlet and supply valves;
- a pulley assembly with an electro-magnet coupling (1).
1. Pulley with coupling
2. Disc
3. Connecting rod
4. Piston
5. Disc guide pin
6. Inclined plate
7. Crankcase
8. Valve holder plate
9. Regulation valve
10. Valve control bellows
Operation
The alternating drive required for the sliding of the pistons in the bores/liners is produced by the rotary
motion of the inclined plate (6), whilst the variation in the capacity, dependent on the piston stroke, is
chieved through the alteration in the angle of the disc (2) controlling the connecting rods (3).
The inclination of the above mentioned disc depends on the difference in pressure between the intake
duct and the inside of the compressor. This difference, measured by the bellows (10), operates the regu
lation valve (9) and consequently causes the movement of the disc (2).
When the request for conditioned air is high, the regulation valve (9) is positioned in such a way that it
uncovers an opening which places the intake side in contact with the inside of the compressor; as, in this
case, there is no difference in pressure, the compressor operates at maximum capacity corresponding to
the position of the disc illustrated in the previous section.
When the air request is less, the valve is positioned so that the supply section is in contact with the crank
case and, at the same time, it stops the flow between the latter and the intake side activated previously.
Copyright by Fiat Auto 1
Page 131 of 330
Marea- Marea Weekend
2000 range ©
Electrical equipment
Protection and security devices
55.
PROTECTION AND SAFETY DEVICES
All the vehicle supply lines were designed taking into account the most up-to-date directives in terms of
safety and protection, especially to prevent fires.
There are 2 types of protection:
- active protection, aims to reduce the causes of faults "at source"
- passive protection, aims to limit the effects of a fault as much as possible
The first category includes a carefully designed wiring layout with wires positioned and carefully anchored
on tracks that are repaired and protected if necessary.
The cables connected to the alternator and the motor were modified for this reason by adding protective
caps etc. A strengthened sheath was also introduced for some of the more exposed sections of wiring.
The passive protection includes all interventions to reduce faults due to high current (overload, short cir
cuit).
All system fuses were rated based on the nominal absorbtion of the loads activated at the same time, to
ensure intervention in cases of a clear short circuit.
The introduction of a box containing 4 maxifuses with other fuses connected on the outside means all
the supplies can be protected except for the cable that connects the battery to the starter motor and the
cable that connects the starter motor to the recharging alternator. These cables are therefore protected by a
strengthened supplementary sheath.
In "MAXI" fusebox A:
EFI electronic injection fuse (petrol)
GLOW: plug fuse (diesel)
IGN: ignition switch fuse
J/B2 fuse master supply .
J/B1 fuse master supply
Next to the box.
B: fan fuse (see table)
C: ABS 60A fuse
D: second fan fuse: 40A (JTD)
115961 1998
iFil 30A IJ/B21 BOA
fiGNl 4OA IJTBTI BOA
1910JTD
IGLOWl 60A P7B21 80A
MGNI 40A IJ/Bll 80A
FUSE B
30A engine petrol without air conditioner
40A 1596 with air conditioning, JTD
50A 1998 wth air conditioning
Copyright by Fiat Auto 1
Page 139 of 330
Marea-Marea Weekend Electrical equipment
2000 range (§) Location of components on the car
55.
LOCATION OF RELAYS AND FUSES ON THE VEHICLE (BONNET - Petrol engine types)
Fi998l152B 273 274 i * *
3B-3C Power fusebox
96 Power fuse protecting ABS
98 Headlamp washer intermittent function
122 Engine cooling fan low speed relay
123 Engine cooling fan high speed timer
124 Air condiitoning compressor control relay
129 Power fuse protecting engine coling fan
150 Injection system relay feed
151 Lambda probe control relay for fuel pump
and injectors
152 Fuse protecting injection system
152A Fuse protecting injection system
152B Fuse protecting injection system
273 Fuse protecting automatic transmission
system
274 Fuse protecting automatic transmission
system
276 Starter enablement relay
(••) Versions with air conditioning
(*) With automatic transmission
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