1995 RENAULT MEGANE SCENIC sensor

DIESEL EQUIPMENT
Coolant temperature sensor
13
LOCATION
Temperature sensor (1) (black connector)
DIAGRAM
98904RDI1307
The sensor has two functions
•Thermistor (tracks 2 and 3) :
i.e. a resistance which varies with coolant
temperature. The tracks are connected to the
pre-post-heating unit.
•Temperature switch (tracks 1 and 4) :
for operating the EGR solenoid valve.SPECIFICATIONS
Thermistor
Temperature in °C ± 1
Switch status
30closed
20open
Temperature in °C ± 1Resistance Ω
252 610 to 2 990
80310 to 350
Temperature switch
13-39

ANTIPOLLUTION
Fuel vapour recirculation
14
OPERATING PRINCIPLE
The fuel tank is connected to the outside through
the canister.
Fuel vapour is retained by the active carbon in the
canister.
So that the fuel vapour contained in the canister
does not evaporate into the atmosphere when
the fuel tank is opened, a valve isolates the canis-
ter from the fuel tank when the fuel filler cap is
removed.
The fuel vapour contained in the canister is elimi-
nated and burnt by the engine.
To do this, a pipe connects the canister and the in-
let manifold. A solenoid valve is located on this
pipe to control bleeding of the canister.
The operating principle for the solenoid valve is to
give a variable passage diameter (depending on
an RCO signal from the injection computer).
The variation in the selection of passage diameter
for the fuel vapour in the solenoid valve results
from the balance between a magnetic field crea-
ted by the feed to the coil and the force of a re-
turn spring ensuring the valve remains closed.
CONDITIONS FOR CANISTER BLEEDING
During richness regulation
Coolant temperature greater than:
- + 55°C (F3R engine),
- + 15°C (K7M engine),
- + 70°C (E7J engine).
Air temperature greater than:
- - 10°C (F3R engine),
- + 10°C (K7M engine),
- + 20°C (E7J engine).
No load position not recognised (if the throttle
position sensor is faulty, the non-recognition of
the no load condition is replaced by an engine
speed condition
engine speedR > 1500 rpm.).
Outside richness regulation
No load position not recognised.
Coolant temperature less than +15°C for
F3R and
K7M engines (no condition for E7J engine).
If the oxygen sensor is faulty, the canister is bled
when there is no no load.
The cyclical opening ratio for the canister bleed
solenoid valve may be seen using the XR25 and
#23. The solenoid valve is closed for #23 = 0.7 %
(minimum value) except for E7J engines (no #23).
14-4

ANTIPOLLUTION
Exhaust gas recirculation (EGR)
14
K7M engine
Mounting bolt for EGR solenoid valve 2.2
EGR solenoid valve bolt 1
Steel pipe bolts for EGR solenoid valve 1
TIGHTENING TORQUES (in daN.m)
REMOVING THE EGR SOLENOID VALVE
Remove the acoustic tie bar.
Disconnect:
- the air temperature sensor connector (1),
- the oil vapour rebreathing pipe (2).
Slacken the two clips (3) mounting the air duct (4)
and remove it.
Disconnect the accelerator cable (8).
99359R2
From the solenoid valve, disconnect:
- the vacuum pipe (5),
- the electrical connector (6).Remove the two mounting bolts for the EGR
solenoid valve, then remove the valve.
99358R1
REFITTING THE EGR SOLENOID VALVE
Renew the seal.
Refitting is then the reverse of removal.
SPECIAL NOTES
To remove the two steel pipes connecting the EGR
solenoid valve mounting to the exhaust manifold
and the inlet manifold, unclip the two clips (9) on
either side of each pipe.
14-14

ANTIPOLLUTION
Exhaust gas recirculation (EGR)
14
K7M engine
OPERATING CONDITIONS FOR THE EGR SOLENOID
VALVE
The EGR system is operational if the following
conditions are met:
• coolant temperature greater than 20°C,
• air temperature greater than 5°C,
• no load position not recognised and throttle
position less than a set threshold, dependent
on engine speed (at 1024 rpm the throttle
position must be greater than 59 seen
using # 17 ;
at 5120 rpm the throttle position must be
greater than 103 seen using # 17),
• manifold vacuum greater than a certain
threshold.
The EGR solenoid valve is not operated if a fault is
detected with the :
- air temperature sensor,
- manifold pressure sensor,
- throttle potentiometer,
- EGR system.
A status bargraph on the XR25 visualises
operation of the EGR solenoid valve by the
computer.
It is however better to carry out a road test to
show this status. A test with the vehicle stationary,
engine operating under low loads is not
sufficient.
A faulty component in the EGR system will cause
an obvious worsening of the exhaust gas values.
CHECKING THE SEALING AND OPERATION OF THE
EGR SOLENOID VALVE
After the cooling fan has operated at least once,
stop the engine and turn the ignition off.
Disconnect the electrical connector.
Supply a 12 V feed directly to the solenoid valve.
Disconnect the pipe (D) connected to the vacuum
reservoir from the solenoid valve. In its place
connect a vacuum pump.
Create a vacuum of 300 mbars. The pressure
should not drop by more than 2 mbars per second
(120 mbars per minute).
Eliminate the vacuum to return the solenoid valve
to atmospheric pressure.
Run the engine at idle speed.
Create a vacuum of 300 mbars again, the engine
should run at idle speed, but unsteadily. If this is
not the case, replace the solenoid valve assembly.
Erase the computer memory after the operation.
14-16

ANTIPOLLUTION
Catalytic converter - oxygen sensor
14
CHECKS TO BE MADE BEFORE THE ANTI-
POLLUTION TEST
Ensure:
- the ignition system is operating correctly
(correct spark plugs, correctly set plug gap,
high voltage leads in good condition and
correctly connected).
- the injection system is operating correctly
(supply is correct - check using the XR25).
- the exhaust pipe is correct and is sealed.
- the EGR is operating correctly.
Check the vehicle history if possible (run out of
fuel, lack of power, use of incorrect fuel).
CHECKING ANTI-POLLUTION STANDARDS
Run the engine until the engine cooling fan has
operated twice.
Connect a correctly calibrated four gas analyser to
the exhaust tail pipe.
Keep the engine speed at 2500 rpm for
approximately 30 seconds then let the engine
return to idle speed and note the pollutant values.
CO
≤0.3 %
CO
2≥14.5 %
HC
≤100 ppm
0,97
≤λ≤1.03
1
NOTE : λ = ————
richness
λ>1→lean mixture
λ<1→rich mixture
If, after these tests, the values are correct, the
antipollution system is correct.
If the values are not correct, additional tests must
be carried out:
- Check the condition of the engine (condition
of the oil, valve clearances, timing, etc,...),
- Check the correct operation of the oxygen
sensor (see section 17) ,
- test for the presence of lead (see following
page).
If the test for the presence of lead is positive, en-
sure the vehicle uses two or three full tanks of un-
leaded fuel before replacing the oxygen sensor.
If, after all these tests have been carried out, the
values still do not conform, the catalytic converter
must be replaced. Petrol engine
14-21

93703S
This test is only possible using the Nauder lead test kit.
To obtain a test kit, contact your After Sales Head Office.
Part numbers: - For the complete kit: T900
- For a set of 40 test papers : T 900/1
ANTIPOLLUTION
Test for the presence of lead
14
METHOD
Detecting lead at the exhaust
a- Conditions for the test:
- Engine not running
- Exhaust pipe warm but not burning.
- Do not perform the test if the temperature is below 0 °C.
b- If necessary, use a dry cloth to clean the inside of the exhaust pipe to remove soot deposits.
c- Wearing the gloves, moisten a test paper slightly with distilled water (if the paper becomes too wet, it
will lose its efficiency).
d- Apply the moistened test paper to the cleaned section of the exhaust pipe and hold it there with
slight pressure for approximately one minute.
e- Remove the test paper and leave it to dry. If lead is present, the paper will be a red or pinkish colour.
ATTENTION :The test for lead should be carried out on the exhaust tail pipe. It should never be carried out
on the oxygen sensor.
Petrol engine
14-22

STARTING - CHARGING
Starter motor
16
OPTIMA 5800 diagnostic station
CHECKING THE STARTER USING THE DIAGNOSTIC STATION
The starter may be tested using the OPTIMA 5800 diagnostic station, by measuring the battery voltage and
the current used during the starting phase. The following operating faults may be detected:
- battery fault (voltage drops when the starter is activated),
- starter jammed (the current used is too high),
- starter fault (the current used is too low).
To carry out the test the vehicle must be prevented from starting:
- E7J, K7M engines : disconnect the engine speed sensor (on the clutch bellhousing),
- F3R engines : disconnect the engine speed sensor (on the gearbox),
- F8Q engines : disconnect the fuel shut off on the pump and insulate the terminal.
NOTE :
- an open circuit on the engine speed sensor or the ignition creates a fault which is memorised in the injec-
tion computer. Erase this fault using the XR25 (see injection section),
- if the vehicle is fitted with an immobiliser, just lock the doors using the PLIP.
FAULT FINDING
SPECIAL TOOLING REQUIRED
16-10

98900-1R
IGNITION
Static ignition
17
The differences between static ignition with two
coils and distributed ignition are:
- the high voltage distributor is no longer used,
- two dual output coils are used.
PRESENTATION
The system comprises:
- the injection computer (the ignition power
stage is integrated into the computer),
- two dual output coils,
- four spark plugs,
- an anti-interference condenser.
DESCRIPTION - OPERATING PRINCIPLE
COMPUTER
The injection computer (120), depending on the
information received from various sensors, but
principally depending on the engine speed and
load, determines:
- the number of degrees of advance to be used
and consequently the ignition point,
- which cylinders are at TDC and consequently
the ignition coil to be operated.
The spark is created at the two cylinders at TDC by
cutting the earth to the coil concerned.
COILS
There are two coils. They are of the dual output
type.
They are controlled separately by the computer.
They create two sparks at the same time.They have a foolproofing device (K7M engine):
- on their base to prevent them being fitted in-
correctly to the rocker box cover,
- at the retaining clips for the high voltage
leads.
They are colour coded on the 3 track electrical
connectors.
Coil (2) has a black electrical connector. This coil
provides the sparks for cylinders 1 and 4 at the
same time. It is controlled by track 28 on the injec-
tion computer.
Coil (3) has a grey electrical connector. This coil
provides the sparks for cylinders 2 and 3 at the
same time. It is controlled by track 29 on the injec-
tion computer.
Both coils are connected to an anti-interference
condenser (1).
F3R engine
F3R - K7M
engines
17-2