light RENAULT MEGANE SCENIC 1995 Service User Guide

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

INJECTION
Injection fault warning light
17
PRINCIPLE FOR ILLUMINATION OF THE INJECTION FAULT WARNING LIGHT ON THE INSTRUMENT PANEL
• Vehicle without engine immobiliser system
When the ignition is turned on, the warning light illuminates for 3 seconds then extinguishes.
• Vehicle with engine immobiliser system deactivated
When the ignition is turned on, the warning light illuminates for 3 seconds then extinguishes.
When the doors are unlocked, the red immobiliser warning light, which was previously flashing, extin-
guishes. When the ignition is turned on, it illuminates for 3 seconds then extinguishes.
• Vehicle with engine immobiliser system activated
When the ignition is turned on, the computer does not identify the code and the vehicle cannot be star-
ted. The injection warning light illuminates for 3 seconds then extinguishes.
Before the ignition is turned on, the red immobiliser warning light flashes. When the ignition is turned
on, this light flashes twice as fast.
If a fault in the immobiliser system is detected when the engine is running, the injection warning light
will flash in the engine speed range from idle speed to 1 500 rpm approximately.
• Fault with an injection system component
Faults in the following components cause the warning light to illuminate:
- absolute pressure sensor,
- throttle position potentiometer,
- injectors,
- idle speed regulation stepping motor (K7M engine),
- idle speed regulation valve (F3R engine),
- no vehicle speed information when the vehicle is moving,
- EGR solenoid valve (K7M 703 engine),
- automatic transmission computer → injection computer (F3R - K7M engines).
17-24

INJECTION
Engine immobiliser function
17
This vehicle is fitted with a 2nd generation engine immobiliser system.
REPLACING THE INJECTION COMPUTER
The computers are supplied uncoded but are capable of being programmed with a code.
When replacing the computer, the vehicle code must be programmed in and then check that the immobiliser
system is operational.
To do this, carry out the following operations:
•Vehicle fitted with a PLIP engine immobiliser system
- Lock and unlock the doors using the PLIP.
- Turn the ignition on for a few seconds.
- Lock the doors using the PLIP, the immobiliser function is operational.
•Vehicle fitted with a coded key engine immobiliser system
Turn the ignition on for a few seconds then turn it off again.
CHECKING THE IMMOBILISER FUNCTION
•Vehicle fitted with a PLIP engine immobiliser system
- Turn the ignition off, lock the doors from inside the vehicle using the PLIP. The red immobiliser
warning light should flash.
- Turn the ignition on, The red immobiliser warning light should flash twice as fast.
•Vehicle fitted with a coded key engine immobiliser system
Remove the key from the ignition switch, after 10 seconds the red immobiliser warning light should flash.
TESTING AN UNCODED INJECTION COMPUTER FROM STOCK OR FROM A VEHICLE NOT FITTED WITH AN
IMMOBILISER SYSTEM
To avoid coding the injection computer before the test, it is vital to cut the + 12 V before ignition feed to the
immobiliser system. Remove the passenger compartment connection unit fuse (F39) (for more details, refer
to section 82).
NOTE : if the injection computer has been coded by mistake, a method exists for decoding it (refer to section
82).
SPECIAL NOTES
Using the XR25 it is possible to see if the injection computer is coded. The computer is uncoded if bargraph 2
right hand side is illuminated and if *22 = 2 DEF
A CODED COMPUTER FITTED TO A VEHICLE WITH AN ENGINE IMMOBILISER MAY NOT BE USED FOR TESTING
ANOTHER VEHICLE, REGARDLESS OF WHETHER THIS VEHICLE HAS AN ENGINE IMMOBILISER OR NOT.
17-25

INJECTION
Richness regulation
17
Non-loop mode
When richness regulation is occurring, the operating phases when the computer ignores the voltage in-
formation from the oxygen sensor are:
- Full load: #35 = variable and greater than 128
- Sharp acceleration: #35 = variable and greater than 128
- Sharp deceleration with no load information (injection cut) : #35 = 128
- Oxygen sensor fault: #35 = 128
DEFECT MODE IN THE EVENT OF AN OXYGEN SENSOR FAULT
If the voltage from the oxygen sensor is incorrect (# 05 varies only slightly or not at all) during richness regu-
lation, the computer will only enter defect mode (# 35 = 128) if the fault has been present for 3 to 5 minutes.
The fault will be memorised in this case only.
If an oxygen sensor fault is present and recognised and if the fault has already been stored, the system enters
the open loop mode directly (# 35 = 128).
17-35

INJECTION
Operating wiring diagram
17
E7J engine
COMPUTER TRACK ALLOCATION
TrackALLOCATION
1Power earth
2Electronic earth
3Vehicle speed information
4+ before ignition (permanent) computer memory
5Canister bleed signal (sequential earth period)
6Pump relay control (via track N° 2)
7Locking relay control (via track N° 2)
8Diagnostic line for erasing the memory and power assisted steering pressostat information
9Throttle position potentiometer information (pin N° 4 on 222)
10Heater relay command
11TDC sensor signal (track B)
12Rev counter information at instrument panel
13Connection with injection fault warning light on instrument panel
14Air temperature information
15Coolant temperature information
16+ 5 V feed for absolute pressure sensor and throttle potentiometer
17Common earth for absolute pressure sensor, throttle potentiometer and coolant temperature
sensor
18Emission of diagnostic signal to diagnostic socket
19Main computer feed via injection locking relay
20Air conditioning compressor command
21Injector control via earth
22Not used
23+ or - feed to idle speed micromotor (pin N° 1)
24+ or - feed to idle speed micromotor (pin N° 2)
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