ignition RENAULT MEGANE SCENIC 1995 Service Owner's Guide

INJECTION
Special notes on semi-sequential injection
17
K7M engine
OPERATING PRINCIPLE
The K7M engine is fitted with semi-sequential injection.
Injection of fuel is carried out simultaneously to cylinders 1 - 4 and cylinders 2 - 3.
To do this, the two pairs of injectors are connected to two injection computer tracks:
- the injectors for cylinders 1 and 4 are connected to computer track 4 ,
- the injectors for cylinders 2 and 3 are connected to computer track 30 .
For each cylinder, there is one injection per revolution, i.e. two per cycle. These injections take place during
the compression and exhaust phases.
The injection computer uses the same system as that used to control the ignition coils for determining when
to control which injector. By analysing the signal from the flywheel, it knows the TDC point for cylinders 1 - 4
and cylinders 2 - 3 (see principle in section 17 "Ignition"). By counting the number of teeth, the engine phases
preceding TDC maybe determined.
17-17

INJECTION
Special notes on semi-sequential injection
17
K7M engine
cylinder 2compression expansion exhaust inletTDC
TDC
cylinder 3
exhaust inlet compression expansionTDC
cylinder 1
TDC TDC
inlet compression expansion exhaustTDC
cylinder 4expansion exhaust inlet compression
TDCTDCTDC
computer track
N° 4
12 V
0 V
computer track
N° 30
12 V
0 V
Ignition
1revolution 1revolution
1 cycle
injection of petrolTDC
17-18

INJECTION
Special notes on sequential injection
17
F3R engine
PRINCIPLE FOR RECOGNISING THE CYLINDER AT THE INLET PHASE
Depending on the signal from the TDC sensor, the computer knows at what moment cylinders 1 and 4 are at
TDC and at what moment cylinders 2 and 3 are at TDC. (For further explanations refer to section 17
"Ignition").
Cylinders 1 and 4 are at TDC,
- if the signal from the cylinder reference sensor is 0 Volts, cylinder 4 is at the start of the inlet phase,
- if the signal from the cylinder reference sensor is 12 Volt, cylinder 1 is at the start of the inlet phase.
Cylinders 2 and 3 are at TDC,
- if the signal from the cylinder reference sensor is 0 Volts, cylinder 3 is at the start of the inlet phase,
- if the signal from the cylinder reference sensor is 12 Volt, cylinder 2 is at the start of the inlet phase.
LOGIC
Signal from cylinder
reference sensorCylinder at start of inlet phase
12 Volt 1
0 Volts 4
12 Volt 2
0 Volts 3Cylinder at TDC
1 - 4
2 - 3
17-20

INJECTION
Special notes on sequential injection
17
F3R engine
CYLINDER REFERENCE SENSOR CONNECTIONS
TRACK ALLOCATION
1 Earth
2 Information to injection computer on track 42
3 +after ignition
1REMOVAL2REFITTING
DI1701DI1702
DI1703
3ADJUSTMENT
17-23

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
Computer configuration as a function of the gearbox type17
F3R engine
The display shows:
CONFIGURING THE COMPUTER DEPENDING ON GEARBOX TYPE (MANUAL OR AUTOMATIC)
Each time the injection computer is replaced, the gearbox type for the vehicle must be programmed (manual
or automatic). The computer is designed to operate with both these types of gearbox.
Procedure for configuring the computer:
Connect the XR25
ISO selector on S8
Turn the ignition on
Enter D13 then
For a vehicle fitted with a manual gearbox:
Enter G60*
For a vehicle fitted with an automatic transmission:
Enter G50*
If the configuration has not been programmed
After programming the configuration, turn the ignition off to store it in the memory. Memorisation is effec-
tive after the ignition has been turned off, once the computer has left the monitoring mode.
The monitoring mode varies from 30 seconds to 13 minutes.
then once the configuration is
complete
17-26

INJECTION
Computer configuration as a function of the gearbox type17
F3R engine
To check that storing has been correctly carried out, turn the ignition on using fault finding fiche n° 27, bar-
graph 20 LH side should be extinguished, bargraph 19 RH or LH side should be illuminated.
There is a method for configuring the computer which does not require the use of the XR25. To do this:
- turn the ignition on,
- start the engine,
- accelerate the engine to a speed greater than 2500 rpmfor 10 seconds,
- turn the ignition off,
- turn the ignition on again and start the engine,
- accelerate the engine to a speed greater than 2500 rpm for 10 seconds,
- turn the ignition off.
The memorisation procedure is the same as that described previously.
NOTE : the configuration procedure using the XR25 may be used to reconfigure an incorrectly configured
computer (automatic transmission instead of manual gearbox). The procedure which does not use the XR25
will however only work for an unconfigured blank injection computer from stock.
17-27

INJECTION
Injection strategy / air conditioning
17
AIR CONDITIONING / INJECTION COMPUTER CONNECTION
The electrical connection:
- from the air conditioning computer to the injection computer is by one wire. This track only transmits the
information that the air conditioning is operating. The injection computer deduces that the air
conditioning has been selected:
track 6 F3R engine
track 5 K7M engine
track 34 E7J engine
- from the injection computer to the air conditioning computer is by one wire. This track transmits the
compressor operation authorisation and prevention information :
track 51 F3R - K7M engines
track 20 E7J engine
PROGRAMMING FOR OPERATION OF THE COMPRESSOR
During certain operating phases, the injection computer prevents operation of the compressor.
Starting the engine
The compressor is prevented from operating for 10 seconds after the engine has been started.
Thermal protection
The compressor clutch is prevented from engaging if the coolant temperature is greater than or equal to :
- + 115°C (F3R and E7J engines)
- + 120°C (K7M engine)
Over-revving protection
The compressor may not operate if the engine speed is greater than :
- 6 000 rpm (F3R engine),
- 5 600 rpm (K7M engine),
- 5 400 rpm (E7J engine).
OPERATING PRINCIPLE
1.Idle speed regulation.
2.Air conditioning operation information becomes ON for the first time since the ignition was turned on.
The driver must select air conditioning from the control panel.
The idle speed is increased to:
F3R engine 900 rpm
K7M engine 850 rpm
E7J engine 900 rpm
The injection computer prevents the compressor from operating to assist the increase in idle speed.
3.2 to 5 seconds after receiving the information for air conditioning operation ON, the computer authorises
operation of the compressor and increases the idle speed regulation solenoid valve percentage opening.
The idle speed does not increase.
17-29

INJECTION
Operating wiring diagram
17
KEY TO OPERATIONAL WIRING DIAGRAMS (E7J, F3R, K7M)
COMPONENT NO DESCRIPTION
109
119
120
146
147
149
193 to 196
218
222
224
225
228
236
238
242
244
247
250
272
310
319
341
371
398
437
565
597
645
649
663
664
679
746
772
777
927
MF
MHOn board computer
Automatic transmission computer
Injection computer
Pinking sensor (located under the inlet manifold for E7J engine)
Absolute pressure sensor
TDC sensor
Injectors
Fuel pump
Throttle position potentiometer
Power assisted steering pressostat
Diagnostic socket
Idle speed regulation micromotor
Fuel pump relay (in engine fuse box)
Injection feed locking relay
Oxygen sensor
Coolant temperature sensor
Instrument panel
Vehicle speed sensor
Air temperature sensor
Ignition power module
Air conditioning control panel
Idle speed regulation solenoid valve
Fuel vapour recirculation solenoid valve
Exhaust gas recirculation solenoid valve (EGR)
Throttle body heater (under throttle body)
Throttle body assembly
Engine fuse box
Passenger compartment connection unit
Idle speed regulation stepping motor
Dual ignition coil n°1 (cylinders 1 and 4)
Dual ignition coil n° 2 (cylinders 2 and 3)
Radio anti-interference condenser
Cylinder reference sensor
Heater relay (in engine fuse box)
Power fuse board (near battery)
Inertia switch
Rear right hand electrical earth
Engine electrical earth (located on the cylinder block between the starter and the al-
ternator for the E7J engine)
17-39