Page 113 of 330

Marea- Marea Weekend 0 *° Engine
2000 range @ Fuel feed system
10.
EMISSION CONTROL DEVICES
The car is equipped with devices designed to reduce polluting emissions in accordance with Euro 3
reguirements:
- Oxidising catalytic converter (1)
- Exhaust gas recirculation circuit (EGR) (2)
- Crankcase blow-by vapour recirculation circuit (3).
4F027XJ01
OXIDISING CATALYTIC CONVERTER
The oxidising catalytic converter is a post-
treatment device used to oxidise CO, HC and
particulate and convert them to carbon dioxide
(C02) and water vapour (H20).
The catalytic converter consists of a ceramic
honeycomb case (1) with its chambers im
pregnated with platinum, a substance that
catalyses oxidation reactions.
Exhaust gases flow through the chambers and
heat the catalytic converter where they trigger
the conversion of pollutants to inert com
pounds.
The chemical reaction involved in oxidising
the CO, HC and particulate is effective at tem
peratures between 200 °C and 350 °C.
Above 350 °C, the sulphur in the diesel begins
to oxidise to produce sulphur dioxide and sul
phuric acid.
EXHAUST GAS RECIRCULATION CIRCUIT (EGR)
This system sends a proportion of exhaust gases to the intake under certain engine service conditions.
This dilutes the fuel mixture with inert gsaes to lower.peak temperature in the combustion chamber; This
helps limit the formation of nitrogen oxides (NOx) and reduces exhaust levels by 30-50%.
4F027XJ02
Copyright by Fiat Auto 27
Page 114 of 330

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
Page 117 of 330
Marea- Marea Weekend 9 *°
2000 range @)
Engine
Fuel feed system
10.
1. Undo the bolts (1) fixing the expansion
joint to the E.G.R. valve, disconnect the
pipe connecting the pneumatic valve and
the solenoid valve, then undo the bolts (3)
and remove the throttle casing.
2. At the bench, undo the bolts (1) and
separate the expansion joint from the throt
tle casing.
The pneumatic valve (2) is secured to the
throttle casing.
E.G.R. VALVE
Removing-refitting
- Remove the throttle casing, following the
description in the previous paragraph.
3. Loosen the bolts (1) fixing the pipe con
necting the E.G.R. and the heat exchanger.
4. Disconnect the electrical connection (1) for
the E.G.R. valve self-adjustment motor; undo
the bolts (2) fixing the E.G.R. valve to the
intake manifold, then lift up the valve and
remove the bolts fixing the pipe connected to
the heat exchanger (loosened previously).
Copyright by Fiat Auto VI 01 i ndate 31
Page 118 of 330
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
Page 119 of 330
Marea- Marea Weekend 9
2000 range ©
Engine
Fuel feed system
Open the band (1) retaining the oil vapour
recovery pipe, then undo the bolts (2) fix
ing the E.G.R. valve heat exchanger
mounting bracket.
Undo the nut (1), located under the ther
mostat, fixing the heat exchanger.
Disconnect the band (1) retaining the cool
ant pipe for the heat exchanger.
Undo the bolts shown in the diagram and
remove the thermostat to allow the subse
quent extraction of the heat exchanger.
Remove the heat exchanger from the en
gine compartment.
Copyright by Fiat Auto VK01 - Update ,f 33
Page 131 of 330

Marea- Marea Weekend
2000 range ©
Electrical equipment
Protection and security devices
55.
PROTECTION AND SAFETY DEVICES
All the vehicle supply lines were designed taking into account the most up-to-date directives in terms of
safety and protection, especially to prevent fires.
There are 2 types of protection:
- active protection, aims to reduce the causes of faults "at source"
- passive protection, aims to limit the effects of a fault as much as possible
The first category includes a carefully designed wiring layout with wires positioned and carefully anchored
on tracks that are repaired and protected if necessary.
The cables connected to the alternator and the motor were modified for this reason by adding protective
caps etc. A strengthened sheath was also introduced for some of the more exposed sections of wiring.
The passive protection includes all interventions to reduce faults due to high current (overload, short cir
cuit).
All system fuses were rated based on the nominal absorbtion of the loads activated at the same time, to
ensure intervention in cases of a clear short circuit.
The introduction of a box containing 4 maxifuses with other fuses connected on the outside means all
the supplies can be protected except for the cable that connects the battery to the starter motor and the
cable that connects the starter motor to the recharging alternator. These cables are therefore protected by a
strengthened supplementary sheath.
In "MAXI" fusebox A:
EFI electronic injection fuse (petrol)
GLOW: plug fuse (diesel)
IGN: ignition switch fuse
J/B2 fuse master supply .
J/B1 fuse master supply
Next to the box.
B: fan fuse (see table)
C: ABS 60A fuse
D: second fan fuse: 40A (JTD)
115961 1998
iFil 30A IJ/B21 BOA
fiGNl 4OA IJTBTI BOA
1910JTD
IGLOWl 60A P7B21 80A
MGNI 40A IJ/Bll 80A
FUSE B
30A engine petrol without air conditioner
40A 1596 with air conditioning, JTD
50A 1998 wth air conditioning
Copyright by Fiat Auto 1
Page 134 of 330
Electrical equipment
Junction unit
Marea-Marea Weekend
2000 range ©
55.
Junction unit
»F11=
~T~ II l;
•F9° |["^FT^1| °F10°ir°F13=
| ^14=- ir=F15«=- II
»F12=
SLHHItHia r i i i •
3F4= ir^F8=1l =F7="|| °F6 = 1
I I I I I 1 I '
14 5 4 12-
lor
1-11-J
I 1
J 7_
a o_o o_o OLD n.
Front view of control unit
and location of fuses
The connectors cannot
be connected incor
rectly as each has its
own unique shape. The
letters identifying the
connectors are the same
as those used in the
wiring diagrams .
NOTE connectors A, C and D: are connected to the front lead.
connectors B,F, I, J and H are connected to the facia lead
connectors E and G are connected to the rear lead
Rear view of control unit
and location of relays.
E1. Switch discharge relay for
starting (30A)
E2. Horn relay (20A)
E3. Heated rear windscreen relay
(30A)
4 Print n° 506.763/23
Page 135 of 330

Marea-Marea Weekend
2000 range Q
DESCRIPTION OF WIRING AND CONNECTORS
CONNECTOR A
N.
No.
Wiring
colour Circuit involved
1 R Supply (+30) from fuse box
2 BR Supply (+30) from fuse box
CONNECTOR c
N. No.
Wiring colour Circuit involved
1 RN Car interior fan power supply (with
air conditioner), air conditioner
control unit
2 MB Fuel pump control, inertia switch
3 AN Car interior fan power supply (only heater), air conditioner control unit
4 H Right dipped beam headlamp
5 HN Left dipped beam, headllamp en
ablement
6 VN Left main beam
7 V Right main beam
CONNECTOR E
N.
No.
Wiring colour Circuit involved
1 RN Right brake light
2 GR Rear view mirror control light
3 RG Left brake light
4 MN Rear window power supply
5 MB Fuel pump, inertia switch
6 -N.C.
7 AN Left rear turn signal
8 -N.C.
9 GR Right rear side light (without check
panel)
10 HL Left number plate light (without
check panel)
11 -N.C.
12 RG N.C.
13 RN N.C.
14 R Supplementary brake light
Electrical system
Junction unit
55.
CONNECTOR B
N. No.
Wiring
colour Circuit involved
1 R Power supply to electric windows, door lock, service control unit, main beam relay, fog lamp, sun-roof, heated seats, cigar lighter
CONNECTOR D
N.
No.
Wiring colour Circuit involved
1 G Left headlamp alignment
2 G Right headlamp alignment
3 G Headlamp alignment control
4 AN Front and left side turn signal
5 AR Alarm control unit power supply
6 HB Right headlamp alignment power
supply
7 H Left headlamp alignment power
supply
8 H Headlamp alignment control
9 B Reversing light control
10 Z Horns.
11 Z Horns.
12 -N.C.
13 GV Right front side light
14 AR Brake light power supply
15 A Front and right side turn signal
16 GL Left front side light
17S -N.C.
18 RN Brake light control
CONNECTOR F
N.
No.
Wiring colour Circuit involved
1 HR Dipped beam control
2 -N.C.
3 LR Main beam control
4 -N.C.
5 G Side light power supply from ignition
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