9-3 Viggen Coupe (9400) L4-2.3L Turbo (B235) HO (1999)
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P-Bus And I-Bus
A smaller number of control modules are connected to the bus in the Saab 9-3 compared with the Saab 9-5.
The two power-train systems, EDC and the diesel pump, are however not connected to the I-bus. These systems require considerably faster
communication so that no delays are noticeable, e.g. when EDC requests a certain fuel mass for injection.
Therefore, they are connected through a separate buss called the P-bus (Powertrain Bus). The P-bus has a data transfer rate ten times higher than that of
the I-bus.
The P-bus is also connected to the MIU (Main Instrument Unit). The MIU ensures that the information that is available on one bus is also available on
the other.
SID uses the following information
