air condition RENAULT SCENIC 2000 J64 / 1.G Technical Note 3426A User Guide

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Injection/air conditioning programming
13
13-14
Injection/air conditioning programming
INJECTION COMPUTER/AC COMPUTER CONNECTION
The compressor is of the variable cubic capacity type.
The injection calculator and the air conditioning calculator are linked by two leads:
– The power absorbed information tells the injection computer the output absorbed by the compressor. It is possible
to see the output absorbed using the diagnostic tool. When air conditioning is engaged the reading should be
between 250 and 5000 Watts.
– The connection from the injection computer to the air conditioning computer. This lead carries information on
whether starting the compressor is authorized or forbidden.
When the air conditioning function is selected, idling speed is modified to reach a maximum of 875 rpm.
IMPORTANT: the absorbed output is never equal to 0, whatever the status of the compressor, engaged or not. The
minimum value read is approximately 250 Watts.

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Injection/air conditioning programming
13
13-15
COMPRESSOR OPERATION PROGRAMMING
During certain stages of operation, the diesel injection computer stops the compressor from functioning.
Engine start programming
The compressor is prevented from operating for 5 seconds after the engine has started.
Recovery of performance
When the position of the accelerator pedal is changed significantly and if the engine speed is less than 3000 rpm,
the compressor is prevented from operation for 5 seconds.
Recovery of output when the vehicle starts moving
If the position of the potentiometer is more than 50 % the engine speed is less than 2250 rpm and the vehicle speed
is below 20 km/h, the compressor is cut for 5 seconds.
Anti-stall protection
If the no load position is not detected, and the engine speed is less than 675 rpm. the compressor is disengaged. It
is engaged again after 5 seconds if the engine speed is increased.
Thermal protection programming
The compressor does not engage in cases where the coolant temperature is greater than + 112 °C.

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Thermal plunger
13
13-19
Thermal plunger
The three thermal plungers are located on a water unit
fixed under the manifold at the engine - gearbox joint.
The objective of the system is to reheat the coolant.
The thermal plungers are supplied with 12 volts by
two relays. One relay controls two thermal plungers,
and the other relay controls one thermal plunger. This
enables control of one, two or three thermal plungers
as required.
The resistance of the thermal plungers is:
0.45 ± 0.05 Ω at 20˚C. Control strategy
When the thermal plungers are operating the idling
speed is brought to 900 rpm.
Thermal plungers cannot operate in the case of:
– preheating,
– post heating,
– heated windscreen selected,
– engine speed below 700 rpm.,
If the conditions mentioned above apply, the thermal
plungers are controlled according to a characteristics
map linked to the air and coolant temperature.
Unshaded zone: Thermal plunger not supplied
Shaded zone: Thermal plunger supplied

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Coolant temperature management
13
13-41
Coolant temperature management
CCTM
This system allows the engine cooling fan to be
controlled by the injection computer. It consists of a
single coolant temperature sensor serving injection,
the engine cooling fan, the temperature indicator and
the instrument panel temperature warning light.OPERATION
The injection computer controls, as a function of the
coolant temperature:
– the injection system,
– the engine cooling fan relays:
!the fan is kept at a low speed if the coolant
temperature exceeds 99 ˚C and stops when the
temperature drops below 96 ˚C,
!the fan is kept at a high speed if the coolant
temperature exceeds 102 ˚C and stops when the
temperature drops below 99 ˚C,
!the fan can be controlled by the air conditioning.
For vehicles without air conditioning, only the low
speed engine cooling fan is operational.
COOLANT TEMPERATURE WARNING LIGHT
(shared with the injection fault warning light)
The warning light is controlled by the computer.
It is illuminated when the temperature exceeds 120 ˚C.
16179R1
244 Coolant temperature sensor (injection and
coolant temperature indication on the
instrument panel).
Three track sensor, two tracks for coolant
temperature information and one track for
indication on the instrument panel.

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Computer
13
13-42
Computer
TRACK ASSIGNMENT
Connector A
H2
H3
H4
G1
G2
G3
G4
F1
F3
F4
E1
E2
E3
E4
D3
D4
C1
C3
B1
B3
A3---
→
→
→
←
→
←
←
←
→
---
←
→
←
→←
→
←
→←
→
---
---THROTTLE POTENTIOMETER SUPPLY (TRACK 2)
OBD WARNING LIGHT
COOLANT TEMPERATURE WARNING OUTPUT
PREHEATING WARNING LIGHT OUTPUT
IMMOBILISER INPUT
FAULT WARNING LIGHT OUTPUT
POWER CONSUMED
THROTTLE POTENTIOMETER INPUT (TRACK 2)
FUEL CUT-OFF SOLENOID INPUT
AIR CONDITIONING INHIBITION OUTPUT
THROTTLE POTENTIOMETER SUPPLY (TRACK 1)
CLUTCH BREAKER INPUT
CONSUMPTION INFORMATION OUTPUT
VEHICLE SPEED INPUT
FAULT FINDING
ENGINE SPEED INFORMATION
THROTTLE POTENTIOMETER INPUT (TRACK 1)
FAULT FINDING
HEATED REAR WINDSCREEN INPUT
THROTTLE POTENTIOMETER EARTH (TRACK 1)
THROTTLE POTENTIOMETER EARTH (TRACK 2)
Connector B
B3
B2
C3
C2
C1
D4
D3
D1
E3
E1
F2
G3
G2
G1
H4
H3
H2
J3
J2
K3
L4
L3
L2
L1
M4
M3
M2
M1←
---
→
←
←
→
←
←
---
---
---
←
---
---
←
←
---
←
---
←
---
---
→
→
---
---
---
→PLUGS DIAGNOSTICS INPUT (1)
EGR POTENTIOMETER POSITION EARTH
PREHEATING RELAY CONTROL
EGR POTENTIOMETER POSITION SIGNAL INPUT
TURBOCHARGER PRESSURE INPUT SENSOR
SUPPLY RELAY CONTROL OUTPUT
AIR TEMPERATURE SENSOR INPUT
DIESEL PRESSURE INPUT SENSOR
+ AFTER IGNITION FEED
COOLANT TEMPERATURE SENSOR EARTH
EGR POTENTIOMETER POSITION SUPPLY
ENGINE SPEED SIGNAL SENSOR
AIR FLOW METER SUPPLY
FUEL TEMPERATURE SENSOR EARTH
AIR FLOW METER SIGNAL INPUT
ENGINE SPEED SIGNAL SENSOR
DIESEL PRESSURE SUPPLY SENSOR
FUEL TEMPERATURE INPUT
TURBOCHARGER PRESSURE SUPPLY SENSOR
COOLANT TEMPERATURE SENSOR INPUT
POWER EARTH
POWER EARTH
TURBO PRESSURE SOLENOID VALVE CONTROL OUTPUT
PRESSURE REGULATOR SOLENOID VALVE CONTROL OUTPUT
POWER EARTH
+ AFTER RELAY
+ AFTER RELAY
EGR SOLENOID CONTROL OUTPUT

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Oil vapour rebreathing
14
14-1
114ANTIPOLLUTION
Oil vapour rebreathing
CIRCUIT DIAGRAM
1Engine
2Oil separator
3Air filter unit
4Inlet manifold
CHECKING
To ensure the correct operation of the anti-pollution
system, the oil vapour rebreathing circuit must be kept
clean and in good condition.AOil vapour rebreathing pipe for the bottom of engine
BOil vapour rebreathing pipe for the top of engine
COil separator
DOil vapour rebreathing pipe linked to the intake
pipes
13042R
DI1322

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Exhaust gas recirculation
14
14-3
OPERATING PRINCIPLE
The valve is controlled by an RCO signal issued by the
injection computer. The RCO signal permits
modulation of the opening of the valve, and
consequently, the quantity of exhaust gas directed
back towards the inlet manifold.
The computer continuously carries out a test to detect
the position of the EGR valve flap.
OPERATING CONDITIONS
The parameters which determine the actuation of the
EGR valve are as follows:
– the coolant temperature,
– the air temperature,
– the air pressure,
– the accelerator pedal position,
– the engine speed.
The EGR function is cut if:
– the battery voltage is less than 9 volts,
– the engine speed is greater than 3000 rpm.,
– a characteristics map (engine speed/load) exceeds a
given threshold,
– the vehicle speed is less than 12 km/h, the engine
speed is less than 1000 rpm and if the coolant
temperature is greater than 60 ˚C for 40 seconds.
The EGR valve is not supplied after engine start
according to a coolant temperature characteristics
map.
time (s)The electric EGR valve is supplied for 40 seconds on
each return to idling speed if the air temperature is
greater than 15 ˚C.
Coolant
temperature (˚C)
15761R
1
2
4
5
6Solenoid supply
Sensor supply
Sensor earth
Solenoid earth
Sensor output
-20 0 17 20

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Alternator
16
16-2
REMOVAL
Put the vehicle on a 2 post lift.
Disconnect the battery as well as all electrical
connections on the alternator.
Separate the diesel filter from its mounting and
remove.
Unclip the power steering reservoir.
Release the air conditioning pipe at (A).
Remove:
– the wiring mounting support (1) and remove the unit,
– the front right wheel as well as the mudguard,
– the accessories belt.Special features of vehicles fitted with air
conditioning:
Before removing the accessories belt, check the
centreline of the automatic tensioner (see
section 07 "Accessories belt tension").
Loosen bolt (A), then bolt (B) until the shoulder is
exceeded while holding the automatic tensioner plate
using a 9.35 mm square, then relax the belt by moving
the ratchet in the direction of the arrow.
Remove:
– the bolts (A) and (B),
– the alternator mountings and remove the alternator. SPECIAL TOOLING REQUIRED
Mot. 1273 Tool for checking belt tension
16870R4
98837-1R4

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Alternator
16
16-3
REFITTING (special notes)
Refit in reverse order to removal.
The belts on vehicles fitted with air conditioning are
tensioned by bringing the automatic tensioner plate to
a stop at bolt (B), without forcing it, using a 9.35 mm
square.
See section 07 "Accessories belt tension" for the
belt tension value for vehicles without air conditioning.
NOTE: never refit a belt once it has been removed,
but replace it.
98837-1R1

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General
62
162AIR CONDITIONING
General
CONSUMABLES
– Oil for DELPHI HARRISON compressor:
PLANETELF PAG 488: 220 cm
3 ± 15
(to be ordered from ELF).
– Refrigerant:
R134a: 780 g ± 35 (Mégane)
R134a: 680 g ± 35 (Scénic)
– Compressor:
DELPHI HARRISON V5
62-1