2009 RENAULT TWINGO ESP

88B-4V3 MR-413-X44-88B000$010.mif
MULTIPLEXING
Fault finding – Introduction88B
MULTIPLEX NETWORK TEST PROCEDURE
–Establish dialogue with the computers storing the vehicle configuration (read identification).
–Read the vehicle configuration in the two computers that store the multiplex network configuration (UCH and
Airbag) for the Vehicle multiplex line network.
–Read the vehicle configuration in the computer that stores the multiplex network configuration (A2/A3 display
computer) for the Multimedia multiplex line network.
–List of computers which support fault finding read from the two configuration computers.
–Computer interrogation.
–Physical (electrical) measurements on the multiplex line network.
IMPORTANT
There are three diagnostic lines, depending on the vehicle options:
Fault finding on the computer using the vehicle multiplex network:
–Injection systems,
–ABS or ABS/ESP or vehicle speed computer (depending on the vehicle equipment),
–UCH,
–Automatic transmission (depending on the vehicle equipment),
–Lighting (depending on the vehicle equipment),
–Instrument panel,
–Airbag/pretensioners,
–Climate control (depending on the vehicle equipment),
–Driving school unit (depending on the vehicle equipment),
–LPG injection (depending on the vehicle equipment).
Fault finding on computers using the multimedia multiplex network (depending on the vehicle equipment):
–Radio (R1-08 or R2-08),
–Multimedia interface (A2/A3 display),
–Multimedia connection (C-box).
Fault finding on the computer using the K line (depending on the vehicle equipment):
–Parking distance control and power-assisted steering.

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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
Fault finding – Introduction88B
REPAIR HELP
Help with detecting computer or faulty segment:
If the multiplex network is completely frozen, this command can isolate multiplex network segments and thereby
rule out those that respond properly to the tool. This makes it easier to pinpoint the cause of the fault.
The algorithm for help with locating faults is intended for dealing with electrical faults present solely in the multiplex
line; it is therefore essential that connectors and computers not attached to the multiplex line V are not taken into
consideration.
A test for multiplex network faults by using physical measurements:
When a multiplex network segment has a short circuit, the computers can no longer communicate with each other or
with the diagnostic tool. At this point, the network test is not operational.
The CLIP tool can identify several types of faults by taking electrical measurements on the multiplex line H and
multiplex line L multiplex network. It can detect a multiplex line L / multiplex line H short circuit, a multiplex line L /
+12 V short circuit, a multiplex line H / +12 V short circuit, and a multiplex line H / earth short circuit.
By disconnecting the connectors then the computers, it is possible to determine or indicate the segment causing the
fault on the multiplex network.

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88B
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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MULTIPLEXING
Fault finding – Function88B
The multiplex network operates in a very similar way.
1. The transmitting computer formats the signal to be sent into a frame that can be identified by other computers.
2. The transmitting computer waits until the network is free, i.e. no other frames are being sent by another
computer.
3. The computer sends its frame.
4. All the other computers receive the transmitted frame. As the frame has already been formatted by the
transmitting computer, the receiving computer can determine whether the frame was meant for it or not.
5. The receiving computers acknowledge receipt of the frame. The transmitting computer will resend the frame if it
does not receive this acknowledgement.
Transmitting frames
The frames are transmitted on two twisted wires in order to avoid electromagnetic interference. These wires are
called multiplex line H and multiplex line L.
To reduce electrical interference when frames are sent, the two wires have differential voltages. In addition,
terminating resistors of 120 Ω are fitted at the ends of the network (in the airbag and injection computers) to
attenuate electrical signal reflections.
The electric signals are digital which means that there are only two levels of differential voltage known as recessive
state (corresponding to logic 1) and dominant state (corresponding to logic 0).
The status is recessive when the potential difference between multiplex line H and multiplex line L is zero (multiplex
line H = multiplex line L = 2.5 V). The status is dominant when the potential difference between multiplex line H and
multiplex line L is equal to approximately 2 V (multiplex line H = 3.5 V and multiplex line L = 1.5 V).

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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)

88B-23
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.

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MULTIPLEXING
Fault finding – Fault finding chart88B
ALP 2No topology diagram or configuration table display at the end of
the multiplex network test
The topology cannot be displayed under the following conditions:
1. The two computers storing the multiplex network configuration have failed to respond.
2. The multiplex network is not operational; therefore dialogue is impossible.
3. The two computers storing the multiplex network configuration do not have the same configurations.
4. On the Multiplex network tab on the configuration screen, an incorrect Diagram version number has been
entered into one of the two computers that store the network configuration.
5. No Network version has been entered into the two computers that store the configuration.
1 –
Vehicle multiplex network
The two computers storing the multiplex network configuration did not respond.
Check first that the computers storing the configuration (Airbag and UCH) are correctly supplied:
–check for earth on connection NAP, and for +12 V supply on connection AP25 on component 756.
–check for earth on connections MAM and NAM, and for +12 V supply on connections AP7, AP43, BP3, BP6,
BP15, BP19, BP49 on component 645.
Check the condition of the multiplex network and the continuity and insulation of the CAN H and CAN L lines
between the computers storing the configuration.
Multimedia multiplex network
The computer containing the multiplex network configuration did not respond.
Check first that the computer storing the configuration (A2/A3 display) is correctly supplied:
check for earth on connection NAM, and for +12 V supply on connection BCP4 and BPT to the display 653.
Check the condition of the multiplex network and the continuity and insulation of the CAN H and CAN L lines
between the computers storing the configuration.
2 – The multiplex network is not operational, therefore dialogue is impossible
(see fault "Multiplex network not operational").
3 – The computers storing the multiplex network configuration do not have the same configurations
(see configuration "Multiplex network configurations").
4 –On the multiplex network tab of the configuration screen, an incorrect diagram version number has
been entered on one of the two computers storing the network configuration
(see configuration "Network configuration").
5 – No diagram version has been entered on the two computers storing the configuration.
(see configuration "Network configuration").