1995 RENAULT MEGANE SCENIC light

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
1. The pre-heating warning light does not operate
TEST SOLUTION
Earth the warning light output of connector (C) using
a 2 A fuse when the ignition is turned on (track B3).
• The fuse blows.
• The warning light does not illuminate.
• The warning light does illuminate.The warning light wiring in the instrument panel is in
short circuit. Repair the wiring.
The bulb is blown or the wiring is faulty.
Replace the bulb or repair the wiring.
Check:
- + battery on connector (A),
- + after ignition on connector (C),
- battery earth on connector (C).
If the feed is correct, replace the pre-post-heating
unit.
2. The pre-heating warning light only operates for a fraction of a second when the ignition is turned on.
TEST SOLUTION
Disconnect connector (B) and test the pre-heating:
• The warning light illuminates and there is a
voltage at the connector outputs (B).
• The warning light illuminates and there is no
voltage at the connector outputs (B).
• The pre-heating warning light illuminates for a
fraction of a second only.Check the plugs circuit. If it is correct, check and
replace the faulty plug(s).
Replace the pre-post-heating unit.
Check the before ignition feed to the pre-heating
unit.
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DIESEL EQUIPMENT
Pre-post-heating unit
13
FAULT FINDING
3. There is no fast idle when engine is cold (with air conditioning option)
TEST SOLUTION
Run the air conditioning.
• The fast idle operates
• The fast idle does not operate.Check the connections at the pre-post-heating unit
(connector C).
Ensure continuity between track C3 of connector (C)
and track 1 on the solenoid valve.
Replace the pre-post-heating unit (ensure the
warning light operates correctly when the ignition is
turned on).
If the fast idle solenoid valve opens the pneumatic
circuit, repair the circuit between the vacuum pump,
the solenoid valve and the diaphragm.
If the solenoid valve does not open the circuit,
measure the voltage between the 2 tracks on the
solenoid valve connector.
•12 volts
Replace the solenoid valve after testing the
connections.
•0 volt
Ensure the following continuities :
- between track 2 on the connector and earth,
- between track 1 and track C3 of the pre-post-
heating unit.
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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
Alternator
16
OPERATION - FAULT FINDING
These vehicles are fitted with alternators with in-
ternal ventilation, an integral regulator and a
warning light on the instrument panel which ope-
rates as follows :
- when the ignition is turned on, the warning
light illuminates,
- when the engine starts, the warning light ex-
tinguishes,
- if the warning light illuminates again when
the engine is running, there is a "charging"
fault.
LOOKING FOR FAULTS
The warning light does not illuminate when the
ignition is turned on.
Check:
- the electrical connections are correct,
- the bulb is not blown (to do this, earth the cir-
cuit; the bulb should illuminate).
The warning light illuminates when the engine is
running
There is a charging fault which could be due to:
- the alternator drive belt being broken or the
charging cable being cut,
- internal damage to the alternator (rotor, sta-
tor, diodes or brushes),
- regulator fault,
- an excess voltage.The customer complains of a charging fault and
the warning light operates correctly.
If the regulated voltage is less than 13.5 V, check
the alternator. The fault could be caused by:
- a destroyed diode,
- a cut phase,
- track contamination or wear.
Checking the voltage
Connect a voltmeter across the battery terminals
and read the battery voltage.
Start the engine and increase the engine speed
until the voltmeter needle stabilises at the
regulated voltage.
This voltage should be between 13.5 V and 14.8 V.
Connect as many consumers as possible, the
regulated voltage should remains between 13.5 V
and 14.8 V.
IMPORTANT: if arc welding is carried out on the
vehicle, the battery and the regulator must be
disconnected.
16-2

SPECIAL NOTES FOR BOSCH MONOPOINT INJECTION
• Use the XR25 with the latest cassette and fiche n° 28.
Read the computer Part Number using code G70*.
Erase the memory using code G0**.
• Injection warning light operational (see principle of ignition section).
• Maximum engine speed before ignition cut-out: 6 500 rpm.
• Corrected idle speed after operation of the air conditioning: 900 rpm.
• Corrected idle speed with wheels at full lock (power assisted steering pressostat information) : 825 rpm.
• Canister bleed solenoid valve controlled by RCO signal depending on engine operating conditions (the
valve is not operated for no load).
• If there is a fault with the absolute pressure sensor, the manifold pressure is recreated depending on the
throttle position and the engine speed.
• Reading of the default values from the air temperature sensor (#03) or coolant temperature sensor (#02),
not the values taken in defect mode by the computer when they are recognised as being faulty.
• There is a+after ignition input (track 30) to inform the computer that the ignition has been turned off
while it remains fed for a few seconds to reposition the idle speed micromotor.
(Avoids false detection of a fault in the engine immobiliser system).
INJECTION
General
17
E7J engine
FITTING A 2ND GENERATION ENGINE IMMOBILISER REQUIRES A SPECIAL PROCEDURE FOR REPLACING THE
COMPUTER.
17-6

INJECTION
General
17
K7M engine
SPECIAL NOTES FOR MULTIPOINT INJECTION
•55 track SIEMENS FENIX 5 computer.
•Semi-sequential multipoint injection. Injectors controlled in pairs (injectors for cylinders 1 and 4 then
injectors for cylinders 2 and 3).
•Static ignition with two coils.
•Canister bleed solenoid controlled by RCO signal.
•EGR solenoid valve controlled by RCO signal (K7M 703).
•Idle speed correction depending on:
- air conditioning,
- heated windscreen,
- power assisted steering pressostat.
•Injection warning light on instrument panel operational.
•Use fault finding fiche N° 27.
FITTING A 2ND GENERATION ENGINE IMMOBILISER REQUIRES A SPECIAL PROCEDURE FOR REPLACING THE
COMPUTER.
17-8

INJECTION
General
17
F3R engine
SPECIAL NOTES FOR MULTIPOINT INJECTION
•55 track SIEMENS FENIX 5 computer.
•Injection cylinder by cylinder (sequential).
•Static ignition with two coils.
•Canister bleed solenoid controlled by RCO signal.
•Idle speed correction depending on:
- battery voltage,
- air conditioning,
- heated windscreen.
•Injection warning light on instrument panel operational.
•Use fault finding fiche N° 27.
•Computer configuration depending on gearbox type (manual gearbox or automatic transmission).
FITTING A 2ND GENERATION ENGINE IMMOBILISER REQUIRES A SPECIAL PROCEDURE FOR REPLACING THE
COMPUTER.
17-10