Rpm Sensor 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

Engine
Fuel feed system
10.
4F012XJ03
Marea- Matea Weekend 9 ™
2000 range (Q)
RPM SENSOR
The rpm sensor is fitted to the engine crank-
case and faces the phonic wheel on the
crankshaft.
The sensor is inductive type, i.e. it works by
varying a magnetic field generated when the
phonic wheel teeth (60-2 teeth) pass in front
of the sensor element.
The injection control unit uses the rpm sensor
signal to determine crankshaft speed and an­
gular position.
Operation
The changeover from full to empty due to the
presence or absence of teeth sets up a mag­
netic flux change sufficient to generate an in­
duced alternating voltage proportional to the
number of teeth on the phonic wheel.
The peak sensor output voltage value, all
things being equal, depends on the distance
between the sensor and the tooth (gap).
1. Steel bush
2. Permanent magnet
3. Sensor case
4. Winding
5. Core
6. Phonic wheel
7. Electrical connection
To obtain the correct signal, the specified gap
between phonic wheel and sensor should be
between 0.8 and 1.5 mm
This distance is not adjustable. When the gap
is not as specified, check the condition of the
sensor and phonic wheel.
Winding resistance
860 Ohm ±110% at 20 °C
1. Maximum magnetic flux
2. Minimum magnetic flux
3. Induced alternate voltage
12 Publication no, 506.763/24

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

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

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