2000 FIAT MAREA Timing sensor

Engine
Fuel feed system
Marea- Marea Weekend © ™
2000 range ©
10.
FUEL SYSTEM OPERATING DIAGRAM
1. Pressure pump
2. Electrically-controlled EGR valve
3. Flow meter
4. Pressure regulator
5. Fuel filter
6. Instrument panel
7. Glow plug preheating control unit
8. Electronic control unit
9. Injection system relay
10. Return manifold (low pressure)
11. RPM sensor
12. Glow plugs
13. Engine coolant temperature sensor
14. Potentiometer on accelerator pedal
15. Switch on brake pedal
16. Switch on clutch pedal
17. Variable geometry turbocharger
18. Timing sensor
19. Injectors
20. Fuel pressure sensor
21. Variable geometry turbocharger control sole­
noid
22. Auxiliary fuel pump
23. Glow plug preheating warning light
24. System failure warning light
25. Pressure relief sensor
26. Fuel temperature sensor
27. Throttle valve
28. Variable geometry actuator
29. Vacuum tank
30. Exhaust gas heat exchanger
2 Publication no. 506.763/24

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

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 ©
Engine
Fuel feed system
10.
TIMING SENSOR
The Hall effect sensor is fitted to the cylinder head and faces the camshaft pulley.
An opening on the pulley allows the timing sensor to detect the engine timing position and indicate it to
the injection control unit.
The injection control unit uses the timing sensor signal to detect TDC at the end of compression.
Operation
A semi-condulator layer, through which a current passes, immersed in a magnetic field (lines of force per­
pendicular to the direction of the current), produces a difference in power, known as Hall voltage.
If the intensity of the current remains constant, the voltage produced only depends on the intensity of the
magnetic field. The intensity of the field can simply be altered periodically to produce a modulated electri­
cal signal. Signal frequency is proportional to the speed with which the magnetic field changes.
To achieve this change, the sensor is crossed by a metal ring (inner part of the pulley) with an opening.
When it moves, the metal part of the ring covers the sensor to magnetic field and the output signal is
therefore low; Conversely, the sensor generates a high signal at the opening when the magnetic field is
present.
This signal, together with the rpm and TDC signals, allows the injection control unit to identify piston po­
sition and determine injection point.
AIR FLOW METER
(DEBIMETER)
The debimeter is located on the air intake
sleeve and is hot film type.
The debimeter contains an intake air tem­
perature sensor.
Operation
The principle of operation is based on a
heated membrane fitted into a measurement
channel through which engine intake air
flows.
The hot film membrane is maintained at a
constant temperature (about 120 °C higher
than incoming air) by the heater coil.
The mass of air flowing through the measure­
ment channel tends to take heat from the
membrane. To keep the membrane at constant
temperature, a certain current level must flow
through the resistance.
Because this current is proportional to the
mass of air that flows to the engine, it can be
measured with a Wheatstone bridge and the
resulting signal is sent to the injection control
unit.
1. Covers
2. Electronic card
3. Sensor
4. Mounting plate
5. Mount
6. o-ring
7. Temperature sensor
Copyright by Fiat Auto 13

Electrical equipment
Component location
Marea-Marea Weekend
2000 range ©
55.
Starting - Electronic ignition and injection - Recharging and warning light
light - Injection system failure warning light - Rev counter (1596)
Insufficient engine oil pressure warning
Component key
3 Power fusebox
4 Junction unit:
6 Instrument panel
8 Left front earth
10 Engine battery earth
12 Ignition switch
18 Left rear earth
2 Left facia earth
55 Front/engine lead connection
56 Fuel level gauge control unit
57 Inertia switch
70 Connection between dashborad/front
cables
132 Petrol vapour cut out solenoid valve
136 Knock sensor
138 Idle adjustment actuator
141A Heated Lambda sensor (upstream of
cat.)
141 B Heated Lambda sensor (downstream of
cat.)
143 Alternator
144 Rpm and TDC sensor
145 Starter motor
146 Potentiometer on throttle valve
150 Injection system relay feed
152 Fuse protecting injection system
155 Ignition coil unit
156 Spark plugs
162 Injector (1st)
163 Injector (2nd)
164 Injector (3rd)
165 Injector (4th)
168 Timing sensor
193 Earth for electronic injection
194 Injection lead/injector braid connection
195 Ignition/ injection control unit (1596)
334 Dual engine temperature sender unit
373 Air pressure and temperature sensor
375 Standardized diagnostic socket
55 Front/engine lead connection
1596
CN6A.
HG6A.
* HN 6A
1 CN n.d.
MB6A.
NZ8_
* ZB n.d
*RG195A_
HM6A
CN n.d. HN 143 *
HG 142
1 95A Injection/ignition electronic control unit (1596)
1596 1 N 141A* 20 L 141A* 29 RN n.d. *
2 NZ141B* 21 BN 127 35 B 127
4 L6A* 23 GN 6A* 36 LR252 [c*
5 V252 0 23 GN70 0 40 AG 127
9 LN 141A* 24 B141B* 41 MG 127
12 R 141B* 25 BR n.d. 0 44 Vn.d.*
13 GV131 25 BR 375 * 46 BG 268 [a
14 AB 127 26 LN6A* 47 C n.d. *
15 SB 150* 27 N 193* 48 S 127
16 GN 252 [cal 28 N 193* 49 NZ252
27 282,9 41 52
O I I I I I I -r-r-r'n , , r'l -r-
rrrri '/ 1 1 1 1 1 1 1 1 1 1 1 \1 L/-HJ 'A i I I i i ,I
40
1 95B Injection/ignition electronic control unit (1596)
1596 53 R144* 65 VB 138* JL. NZn.d. *
54 N n.d. * 66 LR 155 * _ZL HM194*
55 ZB 278 * 67 B 144* _7JL HV194*
56 L136* 68 V278*
57 C138* 69 B 168*
58 HN 138* 70 Z136*
59 GN 155 * 71 HG 194 *
60 S 146* 72 HL194*
62 SN 339 * 75 RN 278 *
64 GR138* 76 BR 146 *
74
67-Jf Mill i i r r-l I I I
60-
IE
L -j |l
53 59
The cables involved in the wiring diagram are marked with an asterisk.
70 Print n° 506.763/23

Electrical equipment
Component location
Marea-Marea Weekend
2000 range ®
Starting - Electronic ignition and injection - Recharging and warning light
light- Injection system failure warning ilight - Rev counter (1998)
Insufficient engine oil pressure warning
Component key
3 Power fusebox
4 Junction unit
6 Instrument panel
8 Left front earth
10 Engine battery earth
12 Ignition switch
18 Left rear earth
22 Left facia earth
40 Brake lights control switch
55 Connection between front/engine cables
57 Inertia switch
70 Connection between dashborad/front
cables
68 Right door mirror
70 Connection between dashborad/front
cables
127 Connection between front left cable/ca­
ble on relay holder bracket
132 Petrol vapour cut out solenoid valve
136 Knock sensor
141A Heated Lambda sensor (upstream of cat.)
141 B Heated Lambda sensor (downstream of
cat.)
143 Alternator
145 Starter motor
148 Earth for electronic injection
150 Injection system relay feed
151 Relay feed for Lambda sensor, electric
fuel pump, injectors
152 Fuse protecting injection system
162 Injector (1st)
163 Injector (2nd)
164 Injector (3rd)
165 Injector (4th)
167 Air flow meter
168 Timing sensor
184 Ignition coils (2nd)
185 Ignition coils (3rd)
186 Ignition coils (4th)
187 Ignition coils (5th) (1998)
189 Variable valve timing
193 I.E. control unit earth
223 Rpm sensors
291 Potentiometer on accelerator pedal
292 Clutch pedal switch
296 Accelerator control lever potentiometer
334 Dual engine temperature sender unit
363 Variable valve timing actuator (998)
364 Motorized throttle body
375 Standardized diagnostic socket
376 Acceleration sensor
55.
55 Front/engine lead connection
1998
* BV n.d
MN 127
' HN 6A
* AR n.d
1 27 Connection between front left cable/cable on relay holder bracket
1998
A1 R n.d.'
HL RN 13
HL BG 190A
A4 AB 190A
HL AG 190A
A6 M3A
HL MN55
HL C n.d. *
J*L MB 4C *
J*L AN n.d.
_§§_ MG 190A
_§£. S 190A
VN3A
66 B190A
_§7_ VG70
R n.d.
C2 BN190A
_2L HL n.d.
C4_ SG n.d.
C5 HRn.fi.'
C6 AR n.d. *
_5L G 190A
A1 R n.d. * B4 S365
HL RN98 B5 VN 98 A3 BV 151 * B6 B365 A4 AB 123 J7_ VG365 J*I
HL AG 122 B8 R 150 A6 M 124 C2 BN365 A7 MN 124 C3 HL98 A8 Cn.d.* C4 SG 98 B1 MB 151 * C5 HR152A* B2 AN 124 C6 AR 152B *
B3 MG 124 C7 G 150*
1 90A Injection/ignition electronic control unit (1998)
1998 3 GV131 22 GN6A 41 BN 127 57 V 167*
6 S 127 24 ZB 291 * 44 VB6A* 59 SB 292 *
7 AN 291 * 25 A n.d* 46 LN6A* 62 AB 127
"U 8 GN 291 * 27 RN n.d. * 47 Cn.d* 63 H 167* "U
9 B 127 30 BG 127 * 48 BV n.d *
13 MG 127 31 G 127* 50 AG 127
15 RV n.d. * 32 BV n.d * 53 BR 375 *
16 BV n.d * 35 L6A* 54 MN 167 *
21 VG376 40 HB 291 * 56 ZN 291 *
32 16
49 33
1 90B Injection/ignition electronic control unit (1998)
1998 1 G n.d. * 17 V n.d. * 32 V184* 52 L165A*
2 G 141B* 19 V162* 33 B n.d. * 54 L 136*
3 G 165* 20 V164* 34 B 141A* 55 L 141 *
4 G 189* 22 V136* 35 B 163* 58 L364*
5 G 132* 23 V141A* 36 B363* 59 L223*
6 G 136A* 24 V364* 38 B 136A*. 60 L141B*
10 G223* 25 V334* 40 B364*
14 G 185* 26 V n.d. * 42 B 168*
15 G 186* 28 V 141B* 49 L n.d. *
16 G 183* 31 V187* 51 L 168*
49 33
* The cables involved in the wiring diagram are marked with an asterisk.
72 Print n° 506.763/23