airbag RENAULT SCENIC 2003 J84 / 2.G General Information

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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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.

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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