air conditioning RENAULT SCENIC 2003 J84 / 2.G General Information

FAULT FINDING INTRODUCTION
ABBREVIATIONS
01E
ABBREVIATIONS MEANING OF ABBREVIATION
ABSAnti-lock braking system
ALPFault Finding Chart
APCAfter ignition
AVCBefore ignition
BVAAutomatic gearbox
BVMManual gearbox
BVRSequential gearbox
CANController Area Network
ACAir conditioning
CDCompact disc
PASPower assisted steering (hydraulic)
EPASElectric power assisted steering
DVDDigital versatile disc
DTCFault finding code
EGRExhaust gas recirculation
ESPElectronic Stability Program
GMVMotor-driven fan assembly
CNGCompressed natural gas
LPG Liquefied petroleum gas
HLEHigh yield strength
MAGMetal active gas (for welding steel)
MIGMetal inert gas (for welding aluminium)
MRWorkshop repair manual
TNTechnical Note
OBDOn board diagnostics
SERResistance welding
SSPPTyre pressure monitoring system
THLEVery high yield strength
TMLabour time
UCHPassenger Compartment Unit
UPCProtection and Switching Unit
UCTRoof control unit
UHLEUltra high yield strength
VINVehicle identification number
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101EFAULT FINDING INTRODUCTION
ABBREVIATIONS

FAULT FINDING INTRODUCTION
General method
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101EFAULT FINDING INTRODUCTION
General method
The Scénic II is a multiplexed vehicle equipped with a communications network operating at a speed of
500 kBauds.
This change has allowed a new optimisation of the electronic layout of the vehicle in two ways:
●Distribution of vehicle functions: the main computers present on the multiplex network manage several
functions (example: UCH: access - vehicle protection - lighting - wipers - passenger compartment heating - tyre
pressure monitor).
●Elimination of redundant sensors: the "steering wheel angle" signal used by the electronic stability program
is produced by the electric power assisted steering which then transmits it to the multiplex network. So the
steering wheel angle sensor used by the electronic stability program does not exist.
This change has also allowed fault finding on computers present on the multiplex network to be performed by the
main communication network of the vehicle (multiplex network) instead of a cable network dedicated to fault
finding (K / L lines).Warning:

Scénic II diagnostics can only be done with the CLIP fault-finding tool equipped with the vehicle diagnostic
probe (part no.: Elé. 1674).
Note:
The multiplex network of the vehicle is the main functional communication network of the vehicle. But
certain optional functions are still performed by track wires.
IMPORTANT
However, the Scénic II still uses two different physical fault finding media:
●The multiplex network: which allows fault finding of the following computers: instrument panel, electric
power assisted steering, airbag, automatic air conditioning, UCH, anti-lock braking system - electronic
stability program, protection and switching unit, injection.
●K / L lines diagnostic network: for fault finding on the following computers: automatic transmission,
automatic parking brake, discharge bulbs and parking assistance.
Some other computers, while connected to the vehicle's multiplex network, have their own "self-test" function:
central communications unit (Carminat), driving school unit or that cannot be diagnosed with the tool: steering
lock (governed by the UCH).
IMPORTANT
Computer supply for the fault finding procedure:
To run fault finding on the vehicle computers, proceed as follows:
●Vehicle card in card reader
●Press and hold start button (longer than 5 seconds) with start-up conditions not fulfilled,
●Connect the diagnostic tool and perform the required operations.

FAULT FINDING INTRODUCTION
General method
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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.

FAULT FINDING INTRODUCTION
General method
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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.

FAULT FINDING INTRODUCTION
General method
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–Testing other computers that support fault finding: this test consists of connection and identification of
the computers present on the vehicle which can support fault finding K / L lines.
●New fault finding topics: the fault finding topics are now split into two separate menus:
–Computer diagnosis:
similar to the existing fault finding topics apart from the changed menu presentation.
The states and parameters menus have been modified to allow simultaneous display of these data items
and divided into screens by function and sub-function (example: "ignition" sub-function in Injection).
In addition, the computer fault finding procedure allows access to the vehicle "repair" menu when replacing
parts to be matched with the vehicle (configuration, programming).
–Fault finding by function:
limited to computer fault finding present on the multiplex network of the vehicle
and to the keyless vehicle, air conditioning and tyre functions. This new type of fault finding allows an
overall diagnosis of a function to be made by simultaneous dialogue with all the computers involved in
providing the service. In this way, it is possible to simultaneously analyse all the components associated with
a function and also simultaneously supervise intersystem exchanges between the computers responsible
for a customer service.
Note:
In the event of detecting a faulty component, it is necessary to switch to computer fault finding mode to
perform the configuration operations - programming the replaced part.
If a function fault is detected, a physical part is replaced: hence the choices made concerning
navigation of the diagnostic tool.

FAULT FINDING INTRODUCTION
General method
01E
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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FAULT FINDING INTRODUCTION
General method
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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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