air conditioning RENAULT TWINGO 2009 2.G Electrical Equipment - Multiplexing Workshop Manual

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INTRODUCTION
Description of the multiplex network:
The multiplex network consists of a twisted pair of wires connected to several vehicle computers.
These two wires are called multiplex line H and multiplex line L.
Depending on the vehicle options, there is a single multiplex network.
–the Vehicle multiplex line (injection, anti-lock braking system/electronic stability program, instrument panel, air
conditioning, rev counter, sequential gearbox, UCH, airbag/pretensioners) is always present,
–the Multimedia multiplex line (navigation, radio, display, hands-free telephone) depending on the vehicle options.
Data is exchanged by the computers on the Vehicle multiplex line and Multimedia multiplex line networks at a
communication speed of 500 kbit/s.
The Vehicle multiplex line network has two computers, each with an internal resistance of 120ΩΩ Ω Ω

(network terminating resistors):
–the injection computer,
–the airbag computer.
The Multimedia multiplex line network has two computers, each with an internal resistance of 120ΩΩ Ω Ω

(network terminating resistors):
–the A2/A3 display,
–the radio.
PURPOSE
–The purpose of the multiplex network test is to determine the computers present on the vehicle's multiplex network
as well as the cause of possible inter-computer communication faults.
–It also serves to determine the functions installed in the vehicle which are often housed in various computers
(distributed functions, e.g.: Air conditioning, Security access, etc.).
–The test also checks the condition of multiplex network segments.
–The multiplex network test can also run fault finding on computers disconnected from the multiplex network; this
provides an overview of the vehicle's electronic layout. Note:
The Vehicle and Multimedia multiplex line networks support fault finding using the RENAULT tool.
MULTIPLEXING
Fault finding – Introduction

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MULTIPLEXING
Fault finding – Introduction88B
Interpreting test result charts
On the Faults tab, the computers are organised into the following groups:
–Not detected 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.
–Not recognised if the computer is detected but cannot be identified from its response.
On the Information tab, the computers are organised and listed as follows:
–Cannot support fault finding, if the computer cannot support fault finding with the tool and therefore was not
queried.
–Valid if the computer responded correctly to the tool's request.
If the Proceed icon in the bottom right-hand corner is selected, a new screen will appear with the following tab:
Under 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.
–Not recognised if the computer was detected but could not be identified from its response.
–Not detected if the computer can support fault finding but failed to respond.
FUNCTION TESTING
The function test can be accessed by clicking on the List of functions icon.
–The vehicle function tests screen resembles the multiplex network test screen with a diagram of the network layout
if this is known and displayed.
–The Function tab displays the different computers involved in the functions, which may be distributed over several
computers.
Examples for the Vehicle multiplex line network:
•Air conditioning: UCH, INJ, and CLIM.
•Access - Safety: UCH and INJ
•Wiping: UCH
•Lighting: UCH
Examples for the Multimedia multiplex line network:
•Radio.
•Multimedia interface (A2/A3 display)
•Multimedia connection (C-box)
–The Info tab displays the other possible functions found on the vehicle concerned.
–Selecting a function from the list of functions enables computers not involved in this function to be shaded, thus
indicating the computers involved in this function.
–The Fault finding button runs fault finding on the function selected from the list.

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Multiplexing enables signals to be sent between different computers on the vehicle, such as:
119 Automatic transmission computer 756 Airbag pretensioners/computer
120 Injection computer 995 Electronic rev counter
247 Instrument panel 1094 ABS/ESP computer
419 Air conditioning computer 1222 Parking distance control computer
502 Power-assisted steering computer 261 Radio
645 UCH 225 Diagnostic socket
653 Multimedia interface (A2/A3 display) 1959 Multimedia connection (C-box)
1222 247 995
502
645
120 119 65310941959
225261419
756
MULTIPLEXING
Fault finding – List and location of components

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Fault finding – Operating diagram88B
Operating diagram of the CAN Vehicle network
Number Description
119 Automatic gearbox
120 Injection computer
247 Instrument panel
419 Air conditioning
502 Power-assisted steering
645 UCH
653 Multimedia interface
756 Airbags
995 Electronic rev counter
1094 ABS
1222 Parking distance control
OBD Diagnostic socket
E134 Splice
R107 Dashboard - front of engine connection
E133 Splice
120
010
11 123
5
6
7 89 OBDE134
E133 R107
645 1094119
419
995
247
653
1222 502 756
MULTIPLEXING
Fault finding – Operating diagram

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MULTIPLEXING
Fault finding – Configuration88B
CAN Vehicle configuration screen
Make sure that the information displayed on the two tabs is correct.
The same configuration information for the two computers is essential for displaying the network topology.
Option: depending on equipment level
CAN Multimedia configuration screen Computer Multiplex network configurationConfiguration of computers that
can support fault finding
Injection (120) PRESENT YES
ABS/ESP (1094) PRESENT YES
Instrument panel (247) PRESENT YES
UCH (645) PRESENT YES
Airbag/pretensioners (756) PRESENT YES
Air conditioning (regulated) (419) PRESENT (option) YES (option)
Sequential gearbox (119) PRESENT (option) YES (option)
Power-assisted steering (502) ABSENT (option) YES (on K line) (option)
Rev counter (995) PRESENT (option) YES (option)
Parking distance control (1222) ABSENT YES (on K line)
A2/A3 display (653) PRESENT (option) YES (option)
Computer Multiplex network configurationConfiguration of computers that
can support fault finding
A2/A3 display (653) PRESENT YES
Radio R1-08 or R2-08 (261) PRESENT or ABSENT (option) YES or NO (option)

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AFTER REPAIRRun the multiplex network test again using the diagnostic tool.
Clear the stored faults on all the computers connected to the network.
Deal with any other faults.
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MULTIPLEXING
Fault finding – Interpretation of faults88B
FAULTY COMPUTER
Vehicle multiplex network
NOTESMake sure that the computers installed in the vehicle are the correct type and are
compatible with the vehicle.
Check that the computers are correctly supplied (earth, + battery feed,
+ accessories feed or + after ignition feed).
Make sure that the computer wake-up mode is in full working order on the vehicle and is properly assimilated
by the computers.
The wake-up mode is:
–Timed supply: UCH,
–+ accessories feed: Air conditioning, ABS/ESP.
–+ after ignition feed: Injection, Airbag/Pretensioners, Sequential gearbox, Instrument panel.
In + accessories feed these computers will not appear.
–Switch to computer fault finding mode.
Attempt to establish dialogue with computers.
No communication from computers to diagnostic tool: see ALP 1
No communication with the computer or computers not communicating with the diagnostic tool.
Check the connections to the computers and that there are no open circuits.
Repair if necessary.
Computers are not displaying all the information on their identifications:
Check in the Workshop Repair Manual or the World Vehicle Database that the computer is compatible
with the vehicle.
Check that the CLIP diagnostic tool update is recent enough to be able to deal with faults on the vehicle.
If no faults or open or short circuits have been detected after these checks, contact Techline.