88B - 17
MULTIPLEXING
Fault finding - Interpretation of faults
88B
V4 MR-372-J84-88B050$700_eng.mif
MULTIPLEX NETWORK NOT OPERATIONAL
NOTESFirst check that the computer at the end of the faulty segment is properly
powered (earth, + battery, + accessories or + after ignition).
Always check the computer conformity.
IMPORTANT
Switch off the ignition or remove the RENAULT card from the card reader, check that
the side lights are off and wait for 1 minute.
Finding the fault
type
NOTESUse the diagram of the multiplex network of the vehicle
(diagram of the diagnostic socket).
Measure the resistance between connections 133B and 133C on the diagnostic socket.
What is the resistance?
0 ΩΩ Ω ΩThe two lines are in short circuit (see Introduction: Repair advice).
Check that there is earth, + battery feed, + accessories feed or + after ignition feed
at the airbag computer and UCH terminals. To allocate the connections on the
computers and connections, use the vehicle diagrams for the airbag computer (756)
and the UCH (645).
For each 133B and 133C connection between the different vehicle computers, check
there is no interference resistance and no short circuit to earth or to the + battery feed.
60 ΩΩ Ω Ω
± 10 ΩΩ Ω Ω
Between 70 ΩΩ Ω Ω
and 110 ΩΩ Ω Ω
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.
