coolant level FIAT MAREA 2000 1.G Workshop Manual

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

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

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.
Copyright by Fiat Auto 5

Engine Marea- Marea Weekend IP ™
Fuel feed system 2000 range o
10.
The EGR valve consists of:
- a Pierburg EGR solenoid (1) operated by engine management unit (2)
- a pipe from the exhaust manifold (4) (from which the exhaust gases flow)
- an air-water heat exchanger (3) (that lowers exhaust gas temperature)
- a pipe connected to throttle body (5) to which exhaust gases are admitted
4
Operation
With coolant temperature > 20°C and engine speeds between 800 and 3000 rpm, the engine management
unit controls the EGR solenoid by means of a square wave signal.
Changes in this signal allow the EGR coil to move a plunger and thus modulate the flow of exhaust gas
from the exhaust manifold to the intake manifold; this achieves two results:
- less air is taken in
- combustion temperature is lowered (due to the presence of inert gases), thus reducing the formation of
NOx (nitrogen oxides).
The engine management control unit is constantly informed of recirculation gas quantity via data from the
debimeter. If the intake of a given quantity of air (Qam) is required for a given rpm and the level sent by
the debimeter (Qar) is lower, the difference (Qgr) is the amount of gas recirculated.
Qam - Qar = Qgr
Qam = stored theoretical air quantity
Qar = actual air quantity
Qgr = recirculated gas quantity
An atmospheric pressure signal is used in controlling the EGR valve to detect when the car is being driven at
altitude. The recirculation gas quantity can then be reduced to prevent engine fumes.
28 Publication no. 506.763/24

Electrical equipment
Instrument panel
Marea-Marea Weekend
2000 range ©
55.
INSTRUMENT PANEL (excluding C.A.)
3 4 56789 10 11 12
21 20 1918 17 24 16 15 14 13 23 22
Front side
1. Fuel level gauge
2. Fuel reserve warning light
3. Speedometer
4. ABS failure warning light
5. Brake pad wear warning light
6. Left direction indicator warning light
7. Side lights warning light
8. Right direction indicator warning light
9. Main beam warning light
10. Low brake fluid level and handbrake ap-
plied/EBD system failure warning light
11. Rev counter
12. Engine coolant temperature gauge
13. Air Bag fault warning light
14. Brake light failure warning light
15. Doors open warning ilght
16. Trip counter/mileometer/outdoor tempera­
ture gauge
17. Low engine oil pressure warning light
18. Generator warning light
19 Injection system failure warning light
20. FIAT CODE system warning light
21. Heater plugs warning light
22. Seat belt warning light
23. Water in diesel filter warning light
24. EOBD warning light
14 Print rf 506.763/23

Marea- Marea Weekend
2000 range ©
Electrical equipment
Control module
55.
Wiring diagram
.mrmmmL 18 3 4 5 6 7 8 9 10 U 1213 1415161718 |TTTTrTrrrrTTTTT1.TTTTT1pmL 18 3 4 5 6 7 8 9 10 11 121314151617181920213223248586
n ti
O Mill
(*) JTD
A. Battery recharging warning light
B. Low engine oil pressure warning light
C. Left direction indicator warning light
D. Right direction indicator warning light
E. Side lights warning light
F. Instrument panel symbol lighting
G. Main beam warning light
H. Air Bag fault warning light
I. ABS failure warning light
J. Fuel reserve warning light
K. Fuel level gauge
L. FIAT CODE system warning light
M. Injection system failure warning light
M1. EOBD warning light
N. Water in diesel filter warning light
O. Heater plugs warning light
(**) TD 75 BHP
P. Seat belt warning light
Q. Brake pad wear warning light
R. Low brake fluid/handbrake on/EBD sys­
tem failure warning light
S. Brake light electronic control module
T. Brake light failure warning light
U. Doors open warning ilght
V. Speedometer
W. Rev counter
X. Engine coolant temperature gauge
Y. Electronic module
Z. Milometer - trip meter/outside tempera­
ture gauge
Z1 Odometer reset button
* Short-circuit plugs
Copyright by Fiat Auto 15

Electrical equipment
Instrument panel
Marea- Marea Weekend
2000 range ©
55.
Rear side (the connector sockets are shown)
Connector A (on front lead) Connector B (on facia lead)
Pin no. Cable colour Circuit involved
1 BV EBD system failure
2 BN Brake fluid level
3 BR Brake pad wear
4 CL Heater plugs (JTD)
5 MN FIAT CODE
6 LN Injection system failure (JTD)
7 HN Battery recharging
8 HG Engine oil minimum pressure
9 LN EOBD (petrol only)
10 RV ABS fault
11 GN Reserve signal (petrol only)
12 VB Speedometer signal
13 AG +30 battery
14 CN Speedometer generator power sup­ply
15 HB engine coolant temperature
16 HL Outdoor temperature signal
17S HM Speedometer signal
18 L Rev counter signal
(*) not connected in this version
Pin no. Cable colour Circuit involved
1 RG Left brake light failure
2 RV Brake light switch
3 RV Brake light switch
4 C Air Bag system fault
5 GV Water in diesel filter (JTD)
6 M Seat belt
7 -N.C.
8 A Left turn signal
9 AN Right turn signal
10 -N.C.
11 GN Side lights
12 LB Main beam headlamps
13 BN Handbrake on
14 RN Right brake light failure
15 H Doors open
16 CN Boot open
17S -N.C.
18 GR Instrument panel light
19 N Lighting earth
20 HG Fuel level
21 GL Outdoor temperature display
22 R +15 from ignition
23 N electronic earth
24 -speedometer signal (*)
25 VN Speedometer signal
26 -speedometer signal (*)
16 Print n° 506.763/23

Marea- Marea Weekend Electrical equipment
2000 range (Q) Control module
55.
Front side
1. Fuel reserve warning light
2. Fuel level gauge
3. Rev counter
4. Direction indicators warning light
5. Analogue speedometer and digital milo­
meter
6. Engine coolant temperature gauge
7. Gears indicator for automatic transmis­
sion
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Electrical equipment
Control module
Marea- Marea Weekend
2000 range ©
55.
Rear side (the connector sockets are shown)
Connector A Connector B
N° Cable
colour Circuit involved
1 HN Generator (G)
2 BN Brake fluid level (J)
3 -Injection system failure (*)
4 AG +30
5 LN EOBD (E)
6 -Not connected
7 -Turbocharging (N)
8 BR Brake pad wear (K)
9 MN Fiat Code (L)
10 -Heater plugs (*)
11 -Not connected
12 HG Minimum oil pressure (H)
13 HM Speedometer signal
14 HL Outside temperature signal
15 CN Speedometer module supply
16 L Rev counter signal
17 HB Coolant temperature gauge
18 -Not connected
19 RV ABS failure (M)
20 -Trailer lights (*)
N° Cable
colour Circuit involved
1 LB Main beam headlamps (D)
2 GR Instrument panel light
3 GN Side lights (C)
4 -Not connected
5 BN Handbrake (J)
6 M Seat belt (I)
7 N Earth
8 -Speedometer signal (*)
9 VB Speedometer signal
10 A Left turn signal
11 AN Right turn signal
12 -Not connected
13 CA Automatic transmission (A)
14 N Earth (electronic)
15 GL Outside temperature switch
16 HG Fuel level
17 R + 15
18 C Air Bag failure (B)
19 GN Fuel reserve
20 -Speedometer signal
(*) not used
18 Print n° 506.763/23

Marea- Marea Weekend
2000 range ©
Electrical equipment
Wiring diagrams
55.
Electrical symbols
M
Lt3
Position
Main beams
Heated seat
Seat belts
Heated rear windscreen
Handbrake applied and
low brake fluid level
ABS
Hazard warning lights
Direction indicator
Handbrake applied and
low brake fluid level
Recharging
Engine oil pressure
IX!
(O)
Hum®
120 Km/h
Choke
Water in fuel filter
Heater plugs warning
light
Turbocharger pressure
Rear fog lamps
Fog light
Brake pad wear
Turbocharger pressure
Automatic transmission
fluid temperature
Speed limits
Fuel level
Engine coolant
temperature
to
Switch discharge
Dipped beams
Central locking direction
indicators signal
Horns
Left direction indicator
Right direction indicator
Engine cooling
Windscreen wiper
Electronic sun-roof
Catalytic converter
temperature
Resistance
Diode
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