APRILIA RSV4 1100 Factory Service Station Manual page 233

RSV4 1100 Factory
The communication protocol is CSMA/CD (Carrier Sense Multiple Access w/ Collision Detection).
In order to transmit, every nod must first check that the BUS (the connection among all devices) is free
before attempting to send a message with BUS (Carrier Sense).
If during this period there is no activity on BUS, every nod has the same chance to send a message
(Multiple Access). If two nodes start transmitting simultaneously, the nodes recognise the "colli-
sion" (Collision Detection) and initiate an exchange action based on message priority (messages remain
unaltered during exchange and there is no delay for high priority messages).
CAN protocol is based on messages and not on addresses. The message itself is divided into several
parts (frames), each of which has a meaning: message priority, data contained, error detection, recep-
tion confirmation, etc.
Every network nod receives all the messages sent through the BUS (with reception confirmation or error
messages) and each nod decides if the message is to be processed or rejected. Besides, every nod
can request information from the other nodes (RTR = Remote Transmit Request).
Level in electrical circuit diagram:
CAN Line
Electrical specifications:
•
between PIN 66 and 80 of the control unit: approx. 120 Ohm
•
between PIN 32 and 33 of the instrument panel: approx. 120 Ohm
Pin out:
•
Line L: White/Black cable between PIN 66 and the Marelli control unit. PIN 32 of the instru-
ment panel, PIN 3 of the LH lights switch and PIN 11 of the ABS modulator.
•
Line H: Orange cable between PIN 80 of the Marelli control panel, PIN 33 of the instrument
panel, PIN 4 of the LH lights switch connector and PIN 2 of the ABS modulator.
CAUTION
BEFORE CARRYING OUT ANY TROUBLESHOOTING, CAREFULLY READ THE GENERAL TROU-
BLESHOOTING CONCEPTS FOR ELECTRICAL DEVICES AT THE BEGINNING OF THE CHECK
AND CONTROL SECTION IN THE ELECTRICAL SYSTEM CHAPTER.
DIAGNOSTIC TOOL: ELECTRICAL ERRORS
U0001 CAN line missing signals
Electrical diagnosis:
•
Bus Off.
Error cause:
•
No communication on CAN line (PIN 66 and/or PIN 80): problem in the entire network (for
example interruption or short circuit to positive or short circuit to ground).
This error is indicated by lighting up in a fixed manner the MI warning light.
Troubleshooting:
Electrical system
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