sensor RENAULT MEGANE SCENIC 1995 Service Owner's Guide

99239R
FUEL MIXTURE
Throttle body
12
Disconnect :
- the accelerator cable (4),
- the oil vapour rebreathing pipe (5),
- the two water hoses (6) which heat the
throttle body after clamping them using tool
Mot. 453-01.
Remove the four mounting bolts for the throttle
body and remove it.
Remove the heat shield between the throttle
body and the manifold. Throttle body mounting bolt
on inlet manifold 2
Throttle potentiometer mounting bolt 0.2
TIGHTENING TORQUES (in daN.m)
REMOVAL
Disconnect the battery.
Remove the three bolts mounting the unit to the
air filter.
99213R
Disconnect:
- the air temperature sensor (1),
- the throttle position potentiometer (8).
Slacken the clip mounting the air sleeve (2) to the
throttle body.
99238R
F3R engine
Remove the air filter and the air sleeve.
12-13

FUEL MIXTURE
Inlet manifold
12
E7J engine
Manifold nuts 2.5
TIGHTENING TORQUES (in daN.m)
REMOVAL
To remove the manifold, the throttle body must
be removed (see previous pages).
There are no special notes for removal.
The inlet manifold is fitted with an electrical
heater (2) with a PTC type resistance (positive
temperature coefficient).
This is mounted in the inlet manifold, opposite
the throttle, and is secured by a circlip.
The heater is fed via a relay by the computer up to
a coolant temperature of 68°C.
If the coolant temperature sensor is faulty, the
heater is permanently fed.
PRM1202
1Retaining circlip.
2 Electrical heater.
3Seal.
REFITTING
When refitting, replace the manifold gasket and
bleed the cooling circuit.
12-15

FUEL MIXTURE
Inlet manifold
12
K7M engine
EGR solenoid valve mounting bolt 1
Inlet manifold bolt and nut 2.5
EGR steel pipe bolt 1
TIGHTENING TORQUES (in daN.m)
NOTE : the fuel gallery must be removed
beforehand (refer to section 13 "Fuel gallery").
REMOVAL
Disconnect the air temperature sensor (1).
Slacken the two clips (2) mounting the air sleeve
to the throttle body and the air filter and remove
the sleeve.
99359R1
99357R
K7M 703 engine
From the EGR solenoid valve, disconnect (8) :
- the hose (9) going to the manifold,
- the electrical connector (10).
Remove the 2 bolts mounting the solenoid valve
(8), then remove the valve.
99358R
Disconnect:
- the accelerator cable (5),
- the throttle position potentiometer connector
(6),
- the idle speed regulation stepping motor
connector (7).
12-16

FUEL MIXTURE
Inlet manifold
12
K7M engine
Unscrew the steel pipe (11) which goes to the
manifold from the EGR solenoid valve mounting
(release the clip first).
All engine types
Remove the two bolts from under the manifold
which mount the wiring retaining bracket.
99460R
From the manifold, disconnect:
- the pipe (12) connected to the absolute
pressure sensor,
- the pipe (13) connected to the brake servo,
- the fuel supply and return pipes.
Disconnect the two hoses from the canister bleed
solenoid valve (14).
Remove the four lower mounting nuts then the
five upper mounting bolts.
99371R
Remove the manifold.
REFITTING
Renew all gaskets and seals which have been
removed.
Refitting is the reverse of removal.
Remember to reclip the clip mounting the EGR
pipe.
12-17

99238R1
FUEL SUPPLY
Fuel gallery
13
Throttle body mounting bolt on manifold 2
Fuel gallery mounting nut 1
TIGHTENING TORQUES (in daN.m)
REMOVAL
Disconnect the battery.
Remove the acoustic tie bar.
Disconnect:
- the air temperature sensor (1),
- the pressure sensor (3),
- the throttle potentiometer (4),
- the cylinder reference sensor (6),
- the fuel vapour recirculation pipe (11),
- the brake servo vacuum pipe (10),
- from the manifold, the pressure sensor
vacuum pipe (7).
Slacken the clip mounting the air sleeve to the
throttle body.
Remove the three nuts mounting the air filter.
99213R1
Remove the filter and the air sleeve.
Disconnect:
- the oil vapour rebreathing pipe (9),
- the coolant temperature sensor (2),
- the idle speed regulation solenoid valve (5). F3R engine
13-5

DIESEL EQUIPMENT
Special notes
13
ALFB (solenoid controlled load dependence)
ROLE
To eliminate the action of LFB load dependence
(internal drop in pressure in the pump and
therefore advance), depending on the engine
temperature and atmospheric pressure.
OPERATION
1. Control by pre-post-heating unit
a)As long as the coolant temperature is <
29°C, the solenoid valve is fed when the
ignition is turned on.
b)If the coolant temperature sensor is faulty,
the solenoid valve is fed when the ignition
is turned on depending on the air
temperature (the air temperature sensor
is located in the pre-post-heating unit).c)If both the coolant and air temperature
sensors are faulty, the solenoid valve is fed
for 200 seconds when the ignition is
turned on.
LOCATION
Coolant temperature sensor (1) (black connector)
DI130198904R
SPECIFICATIONS
Temperature in °CResistance Ω
252 610 to 2 990
80310 to 350
Coolant temperature sensor faulty
13-18

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
Pre-post-heating unit
13
LOCATION
Pre-post-heating unit (A)
This unit has two diodes to prevent the feeding of
the heater plugs when the air conditioning system
is operating and also has a CTN type air
temperature sensor.Coolant temperature sensor (1) (black connector)
99335R
BAir conditioning diaphragm control solenoid
valve on injection pump (fast idle)
CEGR control solenoid valve
98904R
SPECIFICATIONS
Temperature in °C ± 1Resistance Ω
252 610 to 2 990
80310 to 350
13-31

DIESEL EQUIPMENT
Pre-post-heating unit
13
PRINCIPLE OF OPERATION FOR GAS PRE-POST-
HEATING
1. "Pre-heating" when the ignition is turned on
a) Variable pre-heating
The time period during which the warning
light is illuminated and the heater plugs
are fed is dependent on the coolant
temperature.3. "Post-heating" while the engine is running
Post-heating has two phases:
a) Fixed post-heating
After the engine has been started, the
plugs are for for 10 seconds.
b) Variable post-heating
Variable post-heating begins when fixed
post-heating has ended.
During this phase, the plugs are fed
alternately 1 - 3 and 2 - 4 depending on
the coolant temperature.
If the coolant temperature sensor is faulty,
the heater plugs are fed systematically for
14 seconds.
b) Fixed pre-heating
After the pre-heating warning light has
extinguished (variable pre-heating), the
plugs remain fed for up to 8 seconds
before the engine is started.
2. Starting
The plugs remain fed while the starter is
activated.If the coolant temperature sensor is faulty,
the heater plugs are fed systematically for
30 seconds.
Variable post-heating may be
interrupted:
- finally when the coolant temperature
> 65°C,
- momentarily when the unit receives
full load information (post-heating
microswitch opens) for more than 1
second ; post-heating begins again
when the engine returns to idle speed
or low load (microswitch closes).
DI1304
DI1305
13-32

DIESEL EQUIPMENT
Pre-post-heating unit
13
FAULT FINDING
4. Engine operation fault (difficulty in starting, idle speed unstable, noise...)
Check:
- the feed to the pre-post-heating unit :
•+before ignition at connector A.
•+after ignition on track B1 of connector C.
•earth on track C2 of connector C.
- at the pump connector, the resistance of the ALFB solenoid valve (between earth and track
A1) : 7Ω ± 0.5,
- the coherence of the temperature reading given by the coolant temperature sensor,
Temperature (°C) 25 80
Resistance (Ω) 2 610 to 2 990 310 to 350
- the adjustment and operation of the post-heating microswitch,
- the coherence of the open or closed status of the altimetric capsule switch according to the altimetric
pressure of the test site (the switch should be closed for a pressure > 925 ± 20 mbars).
If the fault persists carry out a complete re-adjustment of the pump.
13-35