RENAULT SCENIC 2006 J84 / 2.G Electrical Equipment - Multiplexing Workshop Manual

Electrical equipment
77 11 322 302
"The repair procedures given by the manufacturer in this document are based on the
technical specifications current when it was prepared.
The procedures may be modified as a result of changes introduced by the
manufacturer in the production of the various component units and accessories from
which his vehicles are constructed."
MARCH 2006
All rights reserved by Renault s.a.s.
EDITION ANGLAISE
Copying or translating, in part or in full, of this document or use of the service part
reference numbering system is forbidden without the prior written authority of
Renault s.a.s.
© Renault s.a.s. 2006
MULTIPLEXING
Fault finding - Introduction 88B - 1
Fault finding - Configuration 88B - 4
Diagnostics - Dealing with faults 88B - 7
Fault finding - Fault finding chart 88B - 11
Diagnostics - Repair assistance 88B - 14
88B

MULTIPLEXING
Fault finding - Introduction
88B
88B-1
188BMULTIPLEXING
Fault finding - Introduction
INTRODUCTION
Description of the multiplex network:
The multiplex network consists of a twisted pair of wires connected to several vehicle computers. The two wires are
known as Can H and Can L.
Two of the computers have an internal resistance of 120 Ω (terminating resistance):
–the airbag computer
–the injection computer
The network carries data exchanged by the computers.
The Scénic II is a new-generation multiplex vehicle; the main change is the increase in communication speed to
500 kBauds.
On the Scénic II, only one multiplex network can be diagnosed with the RENAULT tool.
The maximum number of computers on this network is 15.
PURPOSE:
●The purpose of the multiplex network test is to determine the various computers present on the vehicle's multiplex
network as well as the cause of possible inter-computer communication failures.
●It also serves to determine the functions installed in the vehicle, which are sometimes housed in various
computers (distributed functions).
●The test also checks the condition of multiplex network segments.
●The multiplex network test can also run diagnostics on computers disconnected from the multiplex network; this
provides an overview of the vehicles electronic architecture. WARNING
Fault-finding on the Scénic II can only be done with the CLIP diagnostic tool fitted with the new vehicle
connection probe cord (part no. Elé 1674 or 00 00 167 400).
Note:
A second multiplex network for the navigation system may also be present.

MULTIPLEXING
Fault finding - Introduction
88B
88B-2
MONITORING MULTIPLEX NETWORK OPERATION
This step is the essential starting point before any computer diagnostics.
It ensures that the network is correctly connected at the terminals of each computer and that the signal is correctly
sent to it and received by it. On the Scénic II, this function also reads the number of faults present in the computers.
The
multiplex network test function is executed automatically after vehicle selection by the user.
After the network check, the other functions become accessible.
MULTIPLEX NETWORK TEST PROCEDURE:
⇒
Communication established with the computers storing the vehicle configuration (identification read).
⇒
Vehicle configuration read in the two computers that hold the multiplex network configuration (airbag and
UCH on the SCENIC II)
⇒ List of diagnosable computers read in the two configuration computers
⇒ Computer interrogation
⇒ Physical (electronic) measurements on the CAN network. Vehicle computer power supply for diagnostics:
Vehicle card in card reader.
Press and hold (over 5 seconds) the Start button in the absence of start conditions (for example: selecting a
gear).
Connect the diagnostic tool and perform the required operations.
Important: To power the discharge bulb computers, the dipped headlights must be turned on.

MULTIPLEXING
Fault finding - Introduction
88B
88B-3
COMPUTERS
–Valid: green outline, green lettering.
–Undetected: red outline, red lettering.
–Undiagnosable: black outline, black lettering.
–Unknown: red outline, red lettering + exclamation mark.
PISTON RINGS
–Valid: green dash.
–Faulty: red dash.
–Undiagnosed: black dash.
INTERPRETING TEST RESULT CHARTS
On the Problems tab, the computers are organised into the following groups:
–Undetected if the computer failed to respond to the tool's identification request.
–Within the undetected category, the computers are subdivided into Stores multiplex network
configuration and Does not store multiplex network configuration".
–Unknown if the computer is detected but cannot be identified from its response.
On the Information tab, the computers are organised and listed as follows:
–Undiagnosable if the computer cannot be diagnosed with the tool and therefore was not queried.
–Valid if the computer responded correctly to the tool's query.
Clicking on the continue icon in the lower right-hand corner displays a new screen with the following tab:
On the Results tab, the computers are organised into the following groups:
–Faulty if the computer is known and has a non-zero number of faults.
–OK if the computer was detected, recognised and has no faults.
–Unknown if the computer was detected but could not be identified from its response.
–Undetected if the computer can be diagnosed but failed to respond.
FUNCTION TESTING
The vehicle function tests screen resembles the multiplex network test screen in showing a diagram of the network
architecture if this is known and displayed.
The Function tab, displays the various computers involved in the functions whether distributed or not distributed
over the different computers.
The Info tab displays the other possible functions found on the vehicle concerned.
Selecting a function from the list greys out the computers on the diagram that are not involved in that function.
The Diagnostics button runs diagnostics on the function selected from the list.

MULTIPLEXING
Fault finding - Configuration
88B
88B-4
Fault finding - Configuration
MULTIPLEX NETWORK CONFIGURATION
In this vehicle, the two computers holding the multiplex network configuration are the airbag and UCH computers.
The Configuration screen consists of two tabs for displaying and modifying the:
–multiplex network configuration on the first tab,
–diagnosable computer configuration on the second.
LIST OF VEHICLE COMPUTERSWARNING
First repair the computers containing the multiplex network configuration (airbag and UCH) to be able to
display the screen with the multiplex network configuration diagram for the diagnosed vehicle.
ComputerMultiplex network
configurationDiagnosable
computer configuration
Via CANVia the ISO K/L
lines
InjectionPRESENT YES -
ABSPRESENT YES -
Protection and Switching UnitPRESENT YES -
Automatic gearboxPRESENT - YES
LPGPRESENT - YES
Steering lockPRESENT - -
Electric power-assisted steeringPRESENT YES -
Instrument panelPRESENT YES -
UCHPRESENT YES -
Air conditioningPRESENT YES -
Central Communications UnitPRESENT NO NO
Driving school unitPRESENT NO NO
AirbagPRESENT YES -
Automatic parking brakePRESENT - YES
Parking assistanceABSENT NO NO
Discharge bulbsABSENT - YES

MULTIPLEXING
Fault finding - Configuration
88B
88B-5
MULTIPLEX NETWORK GENERIC ARCHITECTURE
Number of multiplex network segments between computers:
* A vehicle can have either LPG or automatic transmission, but never both.
** The vehicle either has just ABS or ABS + ESP (electronic stability program). 120 Injection
118 ABS **
1094 ABS+ESP **
1337 Switching Protection Unit
119 Automatic transmission *
997 LPG / GNV *
1088 Steering lock
1232 Electric power-assisted steering
247 Instrument panel
645 UCH 419 Air conditioning
1125 Control and Communications Unit
469 Driving School Unit
756 Airbag
1217 Automatic parking brake
989 Discharge bulbs
1222 Parking assistance

MULTIPLEXING
Fault finding - Configuration
88B
88B-6
NETWORK CONFIGURATION
NOTESThe configuration is detected with the ignition on.
It can be launched from the multiplex network test results screens.
The tool displays the UCH and/or airbag computer configuration.
Configuration involves the following steps:
–Select the computer to be modified.
–Select the multiplex network diagram version.
The version number increases with each change to the multiplex network wiring in this vehicle.
This information is available in the global vehicle base.
Choice of computers in the vehicle present on the network
The following computers are always fitted to the vehicle:
–Injection
–Protection and Switching Unit
–ABS
–Steering lock (cannot be support fault finding with the tool)
–Instrument panel
–Passenger Compartment Control Unit (UCH)
–Electric power-assisted steering
–Airbag
+ the vehicle options:
–Automatic gearbox
–LPG
–Climate control
–Control and Communications Unit (cannot support fault finding with the tool)
–Automatic parking brake
–Driving School Unit (cannot support fault finding with the tool)
–Discharge bulbs
–Parking assistance
WARNING
A computer connected to the multiplex network but not registered in the computers containing the multiplex
network configuration will not be checked in the multiplex network test.
Adjust the configuration by declaring any missing computers as present in the UCH or airbag computer or both.
Relaunch the multiplex network test after modifying the configuration.

MULTIPLEXING
Diagnostics - Dealing with faults
88B
88B-7
Diagnostics - Dealing with faults
FAULTY SEGMENT
NOTESFirst check that the computer at the end of the faulty segment is properly
supplied (earth, + battery, + accessories or + after ignition).
Always check that the computer is operating correctly.
Important: the tool may not be able to pinpoint the faulty segment(s). It then suggests
several segments that could be faulty. In this event, repair the segment nearest to the
diagnostic socket.
Isolate the faulty segment by disconnecting both ends of the segment. Check the condition of the connections.
Check the continuity of the Can H and Can L lines between the two connectors of the isolated segment.
Refer to the Help with finding short circuits section for computer and connection track allocations.
Perform the necessary operations to ensure the continuity of the two lines (for example, replacing the wiring).
Make sure the computer present in the vehicle is compatible with the Scénic II and that the data it is producing
is correct.
Reconnect the segment.
Carry out a new multiplex network test with the diagnostic tool.
Is the segment still declared faulty?
NoEnd of fault finding.
YesAre there other faulty segments?
NoRepeat the multiplex network tests to check the continuity and
insulation of the Can H and Can L lines between the end of the
faulty segment and the diagnostic socket.
YesApply the same procedure to each segment.
AFTER REPAIRCarry out a new multiplex network test with the diagnostic tool.
Clear the stored faults on all the computers connected to the network.
Deal with any other possible faults.

MULTIPLEXING
Diagnostics - Dealing with faults
88B
88B-8
FAULTY COMPUTER
NOTES–Make sure the computers installed in the vehicle are the correct type and are
compatible with Mégane II.
–Check the power supply to the computers (earth, + battery, + accessories or + after
ignition).
Make sure that the computer wake-up mode is in full working order on the vehicle and properly assimilated
by the computers.
The wake-up mode is:
–timed power supply: UCH, instrument panel.
–+ accessories: Protection and Switching Unit, air conditioning control panel, radio, Control and
Communications Unit.
–+ After ignition: Injection, ABS, airbag, Electric Power Assisted Steering, Automatic transmission, LPG,
Steering lock, Roof control unit, Driving school unit, Automatic parking brake, Parking assistance.
–+ After ignition + dipped headlights: Xenon bulbs.
WARNING
Dialogue with the Xenon bulbs is only possible with + after ignition and the dipped headlights on.
–Switch to computer diagnostics mode.
Test of communication with computers.
⇒No communication from computers to diagnostic tool: see Fault Finding Chart 1
No communication with the computer or computers not communicating with the
diagnostic tool.
Check the connections to the computers and for no open circuit. Repair if necessary.
⇒Computers that only produce partial information when identified:
Check in the Workshop Repair Manual or Global Vehicle Base to see that the computer
really is compatible with Scénic II.
Make sure the CLIP diagnostic tool update is recent enough to handle Scénic II faults.
If after these tests no irregularity or open or short circuit has been detected, contact your Techline.
AFTER REPAIRCarry out a new multiplex network test with the diagnostic tool.
Clear the stored faults on all the computers connected to the network.
Deal with any other possible faults.

MULTIPLEXING
Diagnostics - Dealing with faults
88B
88B-9
UNKNOWN COMPUTERS ON THE NETWORK
NOTES–Check the compatibility of the computers with Scénic II.
Make sure the CLIP diagnostic tool update is recent enough to be able to handle Scénic II faults.
–Switch to computer diagnostics mode.
Test of communication with computers.
⇒No communication from computers to diagnostic tool: see Fault Finding Chart 1
No communication with the computer or computers not communicating with the
diagnostic tool.
Check the connections to the computers and for no open circuit. Repair if necessary.
⇒Make sure the computer identification information is correct and matches the vehicle in
diagnostics.
–Computer information:
–Parts Department part no.:
–Vdiag:
–Program no.:
–Version no.:
–Calibration no.:
If after these tests no irregularity or open or short circuit has been detected, contact your Techline.
AFTER REPAIRCarry out a new multiplex network test with the diagnostic tool.
Clear the stored faults on all the computers connected to the network.
Deal with any other possible faults.