engine coolant FIAT MAREA 2001 1.G User Guide

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

Marea- Marea Weekend 9 ™
2000 range ©
Engine
Fuel feed system
10.
DIAGRAM SHOWING INFORMATION FLOW BETWEN THE INJECTION CONTROL UNIT AND
SENSORS/ACTUATORS
1. Auxiliary fuel pump
2. Variable geometry turbocharger control sole­
noid
3. Climate control compressor
4. Electric EGR valve
5. Rev counter
6. Engine radiator fan
7. Glow plug preheating control unit
8. Potentiometer on accelerator pedal
9. Brake and clutch pedal switches
10. Fuel pressure sensor
11. Intake air flow and temperature sensor (de-
bimeter)
12. Coolant temperature sensor
13. Fuel temperature sensor
14. Pressure relief sensor
15. Timing sensor
16. Rpm sensor
17. Vehicle speed signal
18. Battery
19. Four stage pressure switch
20. Fiat CODE control unit
21. Diagnostic socket
22. Fuel pressure regulator
23. Injectors
24. Throttle valve control solenoid
25. Glow plug preheating warning light
26. Injection system failure warning light
Copyright by Fiat Auto 1

Marea- Marea Weekend 9 ™
2000 range ©) Fuel feed system
Engine
10.
Compents of injection system wiring diagram
1. Vehicle speepd
2. Rev counter
3. Engine radiator fan low speed relay
4. Radiator fan high speed activation relay
5. Potentiometer on accelerator pedal
6. Timing sensor
7. Fuel pressure sensor
8. EGR system modulator solenoid
9. Fuel pressure regulator
10. Glow plug preheating warning light on control panel
11. Injection system failure warning light
12. Air conditioning system relay
13. Coolant temperature sensor
14. Rpm sensor
15. Fuel temperature sensor
16. Diagnostic socket
17. Fiat CODE control unit
18. Four stage pressure switch
19. Injection electronic control unit
20. Pressure relief sensor
21. 7.5A fuse protecting electronic injection system ( + 15 power supply from ignition switch)
22. 7.5A fuse protecting electronic injection system ( + 30 power supply from ignition switch)
23. Main injection system relay
24. 30A fuse protecting injection system
25. Auxiliary fuel pump relay
26. Glow plug preheating control unit
27. Intake air flow and temperature sensor (debimeter)
28. Brake pedal switch
29. Clutch pedal switch
30. Ignition switch
31. Battery
32. Inertia switch
33. Auxiliary fuel pump (submerged in tank)
34. 60A fuse protecting glow plug control unit
35. Cylinder no. 1 glow plug
36. Cylinder no. 2 glow plug
37. Cylinder no. 3 glow plug
38. Cylinder no. 4 glow plug
39. Cylinder no. 1 injector
40. Cylinder no. 2 injector
41. Cylinder no. 3 injector
42. Cylinder no. 4 injector
43. Throttle valve control solenoid
44. Variable geometry turbocharger control solenoid
45. Diesel filter heater relay
Copyright by Fiat Auto 9

Ma tea- Ma tea Weekend !@ ™
2000 range ©
Engine
Fuel feed system
10.
37 Not connected
38 Not connected
39 Not connected
40 Not connected
41 Not connected
42 Not connected
43 Not connected
44 Not connected
45 Not connected
46 Not connected
47 Engine rpm signal output
48 Diagnostic line k
49 Vehicle speed signal input
50 Not connected
51 Activation signal from 4-stage pressure switch
52 Activation signal from 3-stage pressure switch
53 Not connected
54 Not connected
55 Not connected
56 Not connected
57 Not connected
58 Key ON signal
59 Brake switch
60 Air conditioner activation request
61 Clutch switch
62 Glow plug diagnosis
63 Not connected
64 Not connected
65 Not connected
66 Not connected
67 Not connected
68 Not connected
69 Not connected
70 Not connected
71 Not connected
72 Not connected
73 Not connected
74 Not connected
75 Not connected
76 Accelerator pedal 1 earth
77 Accelerator pedal 1 signal
78 Accelerator pedal 1 power supply
79 Accelerator pedal 2 earth
80 Accelerator pedal 2 signal
81 Accelerator pedal 2 power supply
82 Diesel temperature sensor (pin 1)
83 Diesel temperature sensor (pin 2)
84 Coolant temperature sensor (pin 1)
85 Coolant temperature sensor (pin 2)
86 Air flow meter (pin 1)
87 Not connected
88 Air flow meter (pin 3)
89 Air flow meter (pin 5)
90 Fuel pressure sensor (pin 3)
91 Fuel pressure sensor (pin 2)
92 Fuel pressure sensor (pin 1)
93 Turbo pressure sensor (pin 1)
94 Turbo pressure sensor (pin 3)
95 Turbo pressure sensor (pin 2)
96 Not connected
97 Air flow meter (pin 4)
98 Not connected
99 RPM sensor (pin 1)
100 RPM sensor (pin 2)
101 RPM sensor (pin 3)
102 RPM sensor (pin 1)
103 Timing sensor (pin 2)
104 Timing sensor (pin 3)
105 Not connected
106 Not connected
107 Not connected
108 Fuel pressure regulator
109 Fuel pressure regulator
110 Not connected
111 Heater relay control Fuel filter
112 Not connected
113 Not connected
114 Cylinder 4 injector control
115 Not connected
116 Not connected
117 Cylinder 1 and 2 injector power supply
118 Cylinder 3 and 4 injector power supply
119 Cylinder 1 injector control
120 Cylinder 2 injector control
121 Cylinder 3 injector control
Copyright by Fiat Auto 11

Marea- Marea Weekend 9™
2000 range (§)
4F015XJ03
Engine
Fuel feed system
ijo.
ENGINE COOLANT TEMPERATURE
SENSOR
The sensor is fitted to the thermostat and
measures the temperature of the engine cool­
ant by means of an NTC thermistor with a
negative resistance coefficient.
Because the sensor is made using semicon­
ductor technology, the resistance falls if sen­
sor element temperature rises with increasing
coolant temperature.
Because resistance does not change in linear
manner, it is higher at low temperatures than
at high temperatures for the same temperature
increase.
1. NTC resistance
2. Sensor case
3. Electrical connector
FUEL TEMPERATURE
SENSOR
The sensor is fitted on the return manifold and
measures fuel temperature by means of an
NTC thermistor with a negative resistance co­
efficient.
Refer to the previous description of the cool­
ant temperature sensor for sensor operation.
FUEL PRESSURE SENSOR
The sensor is fitted in the middle of the fuel
delivery manifold (rail) and is responsible for
providing a return signal (feedback) to the
control unit in order to:
- adjust injection pressure;
- regulator injection duration.
Copyright by Fiat Auto 15

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

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

Auxiliary Units
Climate control
50
SPECIFICATIONS
TABLE SHOWING QUANTITIES OF OIL AND GAS FOR CLIMATE CONTROL SYSTEM
The table below summarizes the types of oil and the quantities of oil and coolant.
ENGINE TYPE COMPRESSOR TYPE OF
OIL
QUANTITY
OF OIL (cm3)
QUANTITY
OF GAS (g)
1596 16V HR V5 UNICON RL
488 265 600 ± 25
1998 20V SD6V12 SP10 135 600 ± 25
1910 JTD SD 7V16 SP10 135 600 ± 25
FOR ANYTHNING NOT DEALT WITH,
REFER TO THE BASIC MANUAL, ASSEMBLY 50.
Marea-Marea Weekend
2000 range ©
4 Print n' 506.763/23

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