engine RENAULT SCENIC 2003 J84 / 2.G General Information

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Innovations to the Scénic II:
The innovations in Scénic II fall into three categories:
1 - Functional innovations:
The main functional innovations on the vehicle are as follows:
FUNCTIONAL
INNOVATIONS This section describes the new services present on the vehicle and their integration on
the vehicle.
ARCHITECTURAL
INNOVATIONS This section describes the distribution of the main functions and the new computers
fitted to the vehicle.
FAULT FINDING
INNOVATIONS This section describes the fault finding changes implemented on the Scénic II in order
to:
●Allow fault finding on the multiplex network of the vehicle (vehicle to diagnostic tool
connection sensor).
●Develop and complement multiplex network fault finding functions (physical
measurements of the type of fault, fault finding assistance etc.).
●Mask the diversity and complexity of vehicle functions: fault finding by function, multi-
computers, etc.
KEYLESS VEHICLE
(access, protection -
de-protection and
hands-free starting)This function is provided by the following computers:
●UCH: responsible for access and vehicle protection (immobiliser).
●Steering lock: participates in vehicle protection (electromechanical locking of the
steering column).
●Injection: responsible for vehicle protection (immobiliser) and control of the starter
motor.
●Protection and Switching Unit: responsible for the power supplied to the starter motor
at the request of the UCH, and for injection management.
ELECTRONIC
STABILITY
PROGRAMThis function is provided by the following computers:
●Anti-lock braking system - electronic stability program: responsible for the trajectory
analysis function by means of the speed sensors, the yaw sensor, the transverse
acceleration sensor and the steering wheel angle (driver's intention: signal sent by
the electric power assisted steering).
●Injection: management of engine torque in order to correct the trajectory at the
request of the electronic stability program or automatic transmission.
●Automatic transmission: translation (shared with the injection computer) of driver's
intention, sends torque requests to the injection computer.

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2 - Design innovations:
These innovations concern services which are already in use but which are implemented in a specific way on the
Scénic II:
AIR CONDITIONINGThis service is standard on RENAULT vehicles, only the distribution of tasks is
specific:
●Air conditioning: responsible for user intention (management of temperature for
controlled air conditioning) and for mixing and distribution of air in the passenger
compartment (manual and controlled air conditioning).
●UCH: responsible for the heating function.
●Injection: responsible for management of the air conditioning (cold cycle).
●Switching Protection Unit: responsible for the power required for air conditioning
(compressor and engine cooling fan).
WIPERSThe distribution of the function is as follows:
●UCH: responsible for driver's intention, management of the wiper stalk and the rear
screen wiper.
●Switching Protection Unit: responsible for the power required for the windscreen
wiper.
LIGHTINGThis function has already been described in Section 1 - Functional innovations. Refer
to this section for further information.
Note:
In the case of lighting without XENON bulbs, the Switching Protection Unit manages
the dipped headlights.
ENGINE
MANAGEMENT -
INJECTION This function is shared by two computers:●Injection: management of programming and information associated with engine
management, and of the speed regulation and limitation function.
●Protection and Communication Unit: management of the power required for engine
management. The Protection and Communication Unit also incorporates the fuel
pump relay and actuators controlled by cable by the injection computer.

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Lastly, the Scénic II has a Protection and Switching Unit. The main functions of this computer are as follows:
VEHICLE POWER
SUPPLYThe main power relays of the vehicle are directly integrated into the Switching
Protection Unit (including the fuel pump relay and injection actuators).
POWER UNIT FOR
INJECTIONManagement of the starter motor, the air conditioning compressor and the engine
cooling fan.
POWER UNIT FOR
THE UCHManagement of lighting (combined with the Xenon bulbs) and window wipers.
POWER UNIT FOR
AIR CONDITIONINGManagement of the heated rear screen.

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3 - Fault finding innovations:
Development of the electronic and functional design of the Mégane has necessitated changes in the fault finding
processing used. The main fault finding changes are as follows:
●Vehicle to fault-finding tool connection sensor: this equipment is required for communication with the
computers attached to the vehicle's main communications network: the multiplex network. It also enables
communication with the computers diagnosed with the K / L lines.
●New fault-finding tool navigation interface:
The navigation interface of the fault-finding tool has changed to accommodate the Scénic II. Note in particular
the following changes:
–Vehicle identification by entering the VIN:
This can be done manually, or automatically by querying the
vehicle. It also gives the After-Sales type, and the engine and gearbox type.
–Distinction between the fault finding and repair menus:
The fault finding menu incorporates all the
functionalities associated with analysis of an electrical or electronic fault (processing of faults, conformity
checking, actuator commands and processing by customer complaint) whereas the repair menu allows
performance of all the operations associated with replacement of a component and/or modification of the
diagnostic system configuration (configuration read operations, configuration, programming, specific
commands etc.).
●New electronic layout integrity test: As correct operation of the vehicle is dependent on the integrity of the
multiplex network (main functional communication network) and of the cabled electronic systems, the multiplex
network test has changed, becoming the vehicle electronic layout integrity test. The changes are as follows:
–Multiplex network test:
This test remains similar to that already used for RENAULT multiplex vehicles. But it
also incorporates a read of the number of faults from the multiplex computers, physical measurements of the
types of multiplex network faults (open circuit, short circuit to earth, short circuit to the +ve of the faulty rings)
and an assisted help procedure for detecting the defective computer or ring (in the event of total paralysis of
the network). IMPORTANT:
The airbag harness tests and the various physical measurement tests must always be carried out using the
existing diagnostic tool leads and modules.
IMPORTANT:
Entering the VIN, which associated with entering the repair order, can generate the Computer
Diagnostic Sheet electronically.

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Summary list of the computers and functions present on the Scénic II vehicle:
Computer name InstallationFault finding Main function Fault finding sub-
functions
Parking
assistance Optional
●Tool
●K / L lines
●"Backup radar" type
function with beeperNone
AirbagStandard
●Tool
●Multiplex network
●Passive protection by
deployment of airbagsNone
Anti-lock
braking systemStandard
●Tool
●Multiplex network
●Anti-lock braking in braking
phaseNone
Automatic
gearboxOptional
●Tool
●K / L lines (although
present on the
multiplex network)
●Automatic gear change
depending on driver
intentionNone
Driving school
unitOptional
●Self-diagnostic
●Multiplex network
●Management of the "dual
control" systemNone
Manual or
automatic air
conditioning Optional
●Manual air
conditioning cannot
support fault finding
●Tool for automatic
air conditioning
●Multiplex network
●Air conditioning: user
intention and passenger
compartment air
distributionAir conditioning
Electric power
assisted
steeringStandard
●Tool
●Multiplex network
●Power assisted steering Supplies the
steering wheel angle
to the electronic
stability control
program
Electronic
stability control
program
(including anti-
lock braking
system)Optional
●Tool
●Multiplex network
●Anti-lock braking function
●Electronic stability and
understeer programNone
Automatic
parking brakeOptional
●Tool
●K / L lines (although
present on the
multiplex network)
●Automatic parking brake
control while stopping and/
or startingNone
InjectionStandard
●Tool
●Multiplex network
●Engine management
computerKeyless vehicle
Air conditioning
LPG / NGVOptional
●Tool
●K / L lines (although
present on the
multiplex network)
●Injection management
LPG / VNGNone
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Computer name InstallationFault finding Main function Fault finding sub-
functions
Discharge bulb
(domain:
discharge bulb)Optional
●Tool
●K / L lines
●Position and management
of the dipped headlightsNone
Central
Communication
Unit (Carminat)Optional
●Self-diagnostic
●Multiplex network
●Satellite navigation None
UCHStandard
●Tool
●Multiplex network
●Management of access and
the passenger
compartmentKeyless vehicle
Air conditioning
Tyres
Switching
Protection UnitStandard
●Tool
●Multiplex network
●Output management
(mainly engine
compartment)Keyless vehicle
Air conditioning
Instrument
panelStandard
●Tool
●Multiplex network
●Display of vehicle
informationTyres
Steering
column lockStandard
●Does not support
fault finding
(supervised by
the UCH)
●Multiplex network
●Immobilisation of the
steering column (vehicle
protection)Keyless vehicle
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