relay RENAULT MEGANE SCENIC 1995 Service User Guide

FUEL SUPPLY
Fuel cut-out on impact
13
AIM
The aim of this function is to avoid a fire after an
accident due to a fuel leak. To accomplish this, all
components which pump fuel from the fuel tank
are stopped during and after the impact. They
may only be started again by a mechanical action
performed by the driver or repair mechanic.
DESCRIPTION
The system comprises an inertia switch which may
be reset, which:
- detects the impact (1),
- cuts the electrical circuit.
99511R
It is mounted:
• For petrol engines, between track 1 of the
pump relay (236) and the + feed.• For diesel engines, between the + feed and
the fuel shut off (or the coded solenoid valve
if the vehicle is fitted with an engine
immobiliser).
OPERATION
During the impact, the inertia switch ball leaves its
seat and breaks the electrical current.
For petrol engines, the + feed to the pump relay
control circuit (236) is cut. The pump and the
injectors are thus no longer fed electrically.
The fuel in the fuel tank is therefore isolated.
For diesel engines, the + feed to the fuel shut off
or the coded solenoid valve is cut.
The pump can no longer take up fuel, there is no
high pressure any more. Any risk of fire due to
high pressure diesel spray over the engine is
removed.
RESETTING THE SWITCH AND SWITCH
OPERATION
To reset the inertia switch, press the top to
reposition the ball in its seat.
IMPORTANT:
• for petrol engines, after resetting the switch,
the computer memory
MUST be erased using
the XR25. The injection computer will
memorise a pump relay fault when the system
is triggered.
• for diesel engines, after resetting the switch,
the passenger compartment connection unit
memory
MUST be erased using the XR25. This
unit will memorise a break in feed to the
coded solenoid valve.
13-1

FUEL SUPPLY
Fuel cut-out on impact
13
WIRING DIAGRAM
Key
120Injection computer
199Fuel pump
236Fuel pump relay
246Fuel shut off
927Inertia switch
PRJ99472
13-2

FUEL SUPPLY
Pump flow
13
SPECIAL TOOLING REQUIRED
Mot. 1265 Pliers for removing quick release
unions
It is recommended to check the fuel pump flow
using the fuel return pipe connected to the sender
unit assembly.
97163R8
IMPORTANT
During this operation the following points must
be observed:
• Do not smoke and keep all heat sources away
from the working area.
• Take precautions to guard against fuel spray
due to the residual pressure in the pipes when
they are removed.
CHECKING THE PUMP FLOW
Lift the rear seat.
Remove the plastic cover.
Remove the clip (1).
Use tool Mot. 1265 to disconnect the fuel return
pipe (2) (marked by a red quick release union).
Connect an 8 mm semi-rigid pipe to the quick
release union and insert the other end of the pipe
into the 0-2000 ml measuring cylinder.
Shunt terminals (3) and (5) of the fuel pump relay
(located in the engine fuse box). In a period of
one minute the pump flow should be a minimum
of :
- 1.3 litres for F3R - K7M engines,
- 0.83 litres for E7J engines,
for a voltage of 12 Volts.
NOTE : when refitting, ensure the quick release
unions are correctly connected.
If the flow is low, check the feed voltage to the
pump (a drop of approximately 10% is caused for
a drop in voltage of 1 Volt).
EQUIPMENT REQUIRED
1 measuring cylinder 2000 ml
13-10

FUEL SUPPLY
Supply pressure
13
E7J engine
CHECKING THE FUEL SUPPLY PRESSURE
SPECIAL TOOLING REQUIRED
Mot. 1311-01 Fuel pressure test kit
Disconnect the fuel supply pipe (1) from the
throttle body and insert the0 - 10 bars pressure
gauge and the three way union from the test kit
Mot. 1311-01.
99089R
Shunt terminals (3) and (5) of the fuel pump relay
(B) in the engine connection unit (see diagram on
page 13-2).
98756R1
The pressure should be 1.06 bar.
Checking the pump safety valve
If the fuel pressure is correct, feed the fuel pump
and clamp the pipe with the two position valve
for a brief moment. The pressure should stabilise
at approximately 3 bars.
13-11

99366R
FUEL SUPPLY
Supply pressure
13
K7M engine
Fit the 0 ; 10 bars pressure gauge and the hose
Mot. 1311-01.
Shunt terminals (3) and (5) on the fuel pump relay
located in the engine fuse box (see diagram on
page 13-2).
The pressure should be 3 bars ± 0.2.
When a vacuum of 500 mbars is applied to the
pressure regulator, the fuel pressure should be
2.5 bars ± 0.2.
CHECKING THE PUMP SAFETY VALVE (under the
same conditions as previously)
Shunt terminals (3) and (5) of the fuel pump relay
(see diagram on page 13-2).
When the fuel return pipe is clamped briefly, the
pressure should stabilise between 4.5 and 7.5
bars.
13-13

FUEL SUPPLY
Supply pressure
13
CHECKING THE FUEL SUPPLY PRESSURE
SPECIAL TOOLING REQUIRED
Mot. 1311-01 Fuel pressure test kit (with 0 ;+
10 bars pressure gauge included)
99217R1
Disconnect the rear fuel pipe.
Fit the three way valve (1) from tool Mot. 1311-01
and connect the 0 ; + 10 bars pressure gauge.
Shunt terminals (3) and (5) of the fuel pump relay
located in the engine fuse box.
The pressure should be 3 bars ± 0.2.When a vacuum of 500 mbars is applied to the
fuel pressure regulator, the pressure should be
2.5 bars ± 0.2.
CHECKING THE PUMP SAFETY VALVE (under the
same conditions as previously)
Shunt terminals (3) and (5) of the fuel pump relay
(see diagram on page 13-2).
When the fuel return pipe is clamped briefly by
the two position valve, the pressure should
stabilise between 4.5 and 7.5 bars.
F3R engine
13-14

DIESEL EQUIPMENT
Special notes
13
2. Control by altimetric capsule
At altitude, when atmospheric pressure is
approximately 925 ± 20 mbars, the ALFB
solenoid valve is fed via a relay and the
altimetric capsule.
KEY
257Pre-heating unit
597Engine fuse box
711ALFB solenoid valve mounted on injection
pump
741Altimetric capsule
743Altimetric relayLOCATION
Altimetric capsule (741)
PRJ9925799334R
13-19

DIESEL EQUIPMENT
Pre-post-heating unit
13
DIAGRAM KEY
104Ignition switch
163Starter
171Air conditioning clutch
206Air conditioning trifunction pressure switch
247Instrument panel
251Bi-function coolant temperature switch
257Pre-heating unit
398EGR solenoid valve
412Fast idle solenoid valve (AC version)
597Engine fuse box
642AC / pre-heating separation diode
645Passenger compartment fuse box
680Pre-heating unit n° 1
681Pre-heating unit n° 2
682Pre-heating unit n° 3
683Pre-heating unit n° 4
711Diesel fuel pump
741Altimetric capsule
743Altimetric relay
777Power feed for fuse boxConnector (A)
+ Bat+ before ignition feed
Connector (B)
1Feed to heater plugs 1 and 3
2Feed to heater plugs 2 and 4
Connector (C)
A1 / S2Load dependence solenoid valve
control
A2 / PCLoad lever microswitch information
A3 / CTNCTN type sensor coolant temperature
information
B1/+APC+ after ignition feed
B2 / DEMStarter information
B3 / TemPre-heating warning light control (via
earth)
C1 / S1Not used
C2 / -Bat Earth
C3 / ClimFast idle solenoid valve control during
post-heating phase
92206-2R
IDENTIFICATION OF CONNECTORS
13-30

DIESEL EQUIPMENT
Fuel filter
13
LOCATION
Principle of the electric heater
The heater has heated studs. They are ceramic,
made from barium titanate which has a positive
temperature coefficient, meaning that its
resistance increases as its temperature increases.
99332R
1Fuel filter
2Electric heater
3Hand priming unit
The electric diesel fuel heater and the thermostat
are integral in the head of the filter.
DIAGRAM
PRJ99258
449Electric heater
450Diesel heating relay
597Engine fuse box
645Passenger compartment fuse box Operating temperature
Electrical circuit closes: 0°C
Electrical circuit opens: from 8°C
Heater power: 150 W
13-37

INJECTION
General
17
K7M engine
1Injection computer
2Pinking sensor
3Coolant temperature sensor
4TDC sensor
5Fuel vapour recirculation solenoid valve
7Idle speed regulation stepping motor
8Throttle position potentiometer
9Air temperature sensor
10Absolute pressure sensor
11Canister
12Coil for cylinders 1 - 4
13Coil for cylinders 2 - 3
14Fuel pump relay
15Anti-interference condenser
16Air filter
17Oxygen sensor
18Power assisted steering pressostat
19EGR solenoid valve
20Vacuum reservoir
21EGR air filter
LOCATION OF COMPONENTS
17-9