FAULT FINDING INTRODUCTION
General method
01E
01E-2
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
01E
01E-4
LIGHTING - XENON
BULBThis function is provided by the following computers:
●UCH: translation of driver's intention, management of the lighting stalk, the direction
indicators and the rear fog lights.
●Switching Protection Unit: responsible for the power needed for lighting, the side
lights, the main beam headlights and the front fog lights.
●XENON bulb: responsible for management and correction of the dipped headlights.
IMPORTANT
The "discharge bulb" function in the Scénic II involves the following components:
●Two body-height sensors in the front and rear wheel arches on the left side.
The built-in front height sensor as well as the computer that manages
this feature.
●Two units that adjust / produce high-voltage lighting installed in the vehicle's
headlight units.
MULTIMEDIAThis function is provided by the following computers:
●Central Communication Unit (Carminat): responsible for the function.
●Navigation display: displays information relating to navigation.
IMPORTANT
This function may also be provided by the radio display, depending on the type of
navigation (basic - top of the range).
TYRE PRESSURE
MONITORThis function is provided by the following computers:
●UCH: responsible for the function, it also houses the receiver for tyre pressure
signals.
●Instrument panel: displays information relating to the tyre pressure monitor.
Note:
The tyre pressure is monitored by specific valves fitted with tyre pressure sensors.
AUTOMATIC
PARKING BRAKEThis function is provided by the following computers:●Automatic parking brake: manages the function and consists of the computer,
vehicle position sensor (gyroscope) as well as the mechanical cable locking /
unlocking system.
●Instrument panel: displays information about the automatic parking brake feature.
PARKING
ASSISTANCEThis function is provided by the following computers:●Parking assistance: manages the function with the instrument panel beeper
providing the user interface.
FAULT FINDING INTRODUCTION
General method
01E
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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