MULTIPLEXING
Diagnostics - Dealing with faults
88B
88B-10
MULTIPLEX NETWORK OUT OF ORDER
Help finding network short circuits
NOTESGet a copy of the multiplex network wiring diagram for the vehicle and the diagnostic
socket diagram.
In the event of a short-circuit to + battery, leave the battery connected.
The test procedure involves disconnecting the various network components in sequence to pinpoint the faulty
one.
Check the condition of the connectors.
Check the condition of the multiplex network wires (CAN H - CAN L).
Repair the damaged components.
Systematically repeat the multiplex network test after each operation to see if the fault has been resolved. If
the fault is still shown as present, continue disconnecting the connectors and computers one by one.
Input Output
Connector Can H Can L Connector Can H Can L
Protection and Switching Unit Siemens PEH blue 10 8 PEH blue 11/12 7/9
K4J injection S 3000 C 2AN A black A4 A3
K4M - F4R injection S 3000 C 2AN A black A4 A3 2AN B brown K4 K3
K9K injection LVCR 2AN A black A4 A3
F9Q injection EDC 16 C Black A4 A3
Automatic transmission DP0 Black 38 39
ABS - ESP Black 35 14
ABS Black 26 15
Electric power-assisted steering TRW Black 7 5 Black 6
4
Airbag Black 11 10
Climate control Black 7 1
Steering lock Black 3 6
UCH PE 2 black 6 16 10/8 20/18
Instrument panelGrey
30 29 Red 2 3
Driving school unitBlack
A3 B3
Central communications unit Green 6 7 Grey 3 4
Automatic parking brake Grey A3 A2
R 2 Grey 2 3
R 369White
12 13
OBD (On Board Diagnostic)Black
614
If the fault is not visible, 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.
