Potentiometer FIAT MAREA 2001 1.G Workshop Manual

Marea-Marea Weekend Technical Data
2000 range (j§) Engine: fuel system - special tools
OO.io
INTEGRATED ELECTRONIC INJECTION/IGNITION SYSTEM
COMPONENTS
Electronic control unit
Manual gearbox I.A.W. 4EF. B3
Electronic control unit
Automatic transmission I.A.W. 4EF. L1
Air pressure sensor M. Marelli TPRT 05
Fuel vapour solenoid valve M. Marelli EC2
Throttle case M. Marelli 46 SX F2
Idle adjustment actuator M. Marelli IB 02
Injector M. Marelli IWP 109
Fuel pressure regulator MARWALL RPM 84
Coolant temperature sender unit SYLEA 402.386.01
Top Dead Centre and rpm sensor M. Marelli CVM 02
Throttle position sensor (potentiometer) M. Marelli IPF 2C
Detonation sensor NGK KNE 11
Electric fuel pump (*) MARWALL ESS 291
Lambda sensor upstream of catalyzer NTK OZA 534 A1
Lambda sensor downstream of catalyzer NTK OZA 532 A1
Fuel filter MARWALL FA 5325 IN
Timing sensor SYLEA SFA 200
Ignition coil Champion BAE 920A/
BERU 0.040.100.029
SPECIAL TOOLS
(*) Use tool 1870736000 for removing-refitting the fuel pump retaining ring nut
Copyright by Fiat Auto 27

Marea- Marea Weekend 9 \) JTD
2000 range O
Engine
Index
FUEL SYSTEM
- Introduction
- System management strategies
- Fuel system functional diagram
- Diagram showing information ente­
ring/leaving the control unit and
sensors/actuators
INJECTION SYSTEM WIRING DIA­
GRAM
- Injection electronic control unit
- Rpm sensor
- Timing sensor
- Air flow meter
- Injectors
- Engine coolant temperature sensor
- Fuel temperature sensor
- Fuel pressure sensor
- Heater plugs control unit
- Accelerator pedal potentiometer
- Brake pedal switch
- Clutch pedal switch
- Excess pressure sensor
- Atmospheric pressure sensor
page
1
1
1
2
8
10
12
13
13
14
15
15
15
16
16
17
17
17
17
THROTTLE CASING
- Removing-refitting
E.G.R. VALVE
- Removing-refitting
E.G.R. VALVE SELF-ADJUSTMENT
MOTOR
- Removing-refitting
E.G.R. VALVE HEAT EXCHANGER
- Removing-refitting
SOLENOID VALVE ON VACUUM
RESERVOIR FOR THROTTLE CA­
SING PNEUMATIC VALVE
- Removing-refitting
VACUUM RESERVOIR
- Removing-refitting
10.
page
30
31
32
32
34
34
FUEL SUPPLY CIRCUIT 18
- Immersed (auxiliary) pump and fuel
gauge assembly 19
- Fuel filter 19
- Pressure pump 20
- Fuel pressure regulator 20
- Multifunction valve 21
- Supply manifold (rail) 21
- Inertia safety switch 22
AIR SUPPLY CIRCUIT 23
- Throttle case 24
- Turbocharger 25
SUPERCHARGING PRESSURE
CONTROL SOLENOID VALVE
- Removing-refitting 35
FUEL FILTER
- Removing-refitting 35
PRESSURE REGULATOR
- Removing-refitting 36
EMISSION CONTROL DEVICES 27
- Oxidizing catalytic converter 27
- Exhaust gas recirculation circuit
(EGR) 27
- Recirculation circuit for crankcase
vapours (blow-by) 29
Copyright by Fiat Auto VI 01 Cancels anil replaces

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

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 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

Marea-Marea Weekend 9 -™ Engine
2000 range (j§) Fuel feed system
10.
I I TEST
4F017XJ01
A switch (1) on the brake pedal con­
trols the car brake lights; the same
switch sends a signal to pin 59 of the
injection control unit
The control unit uses the "brake pedal
depressed" signal to:
- detect a situation of over-run;;
- check the plausibility of the signal
from the accelerator potentiometer
CLUTCH PEDAL SWITCH
A switch (2) on the clutch pedal is connected to pin 61 of the injection control unit.
The injection control unit uses the "brake pedal operated" signal to distinguish gear engaged and gear
shift conditions.
PRESSURE RELIEF SENSOR
The sensor is fitted to the intake manifold and
the signal sent to the injection control unit is
used to:
- regulate injection pressure;
- regulate injection duration.
The figure alongside shows the sensor and
electrical connector with the following pin-
out:
1. pressure signal
2. Earth
3. Fuel feed system
ATMOSPHERIC PRESSURE SENSOR
The atmospheric pressure signal is built into the injection control unit. It is responsible for measuring at­
mospheric pressure in order to correct measured air flow and reference air flow values to control the EGR
function.
Copyright by Fiat Auto 17

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