System Overview

System Overview

System Overview:

- Main unit, Audio System (353)
- SID (541)
- Amplifier (354)
- Loudspeaker (266)
- Telephone connection (375)
- Steering wheel controls (633)
- Antenna, Viggen (364)

Brief Description












Viggen has been introduced in the M99 range of models with a B235R engine and Trionic T7 engine management system. The bus system in the Viggen is therefore almost identical to that in the 9-5.

The bus system in diesel cars is unchanged from M98 1/2 with EDC 15 and the diesel pump connected to the bus.

Other petrol engine variants have the M2.10 or Trionic T5 engine management system as well as TCM on automatic cars. As earlier, these systems are not connected to the bus.

The two powertrain systems EDC and diesel pump are not connected to the I-bus, however. These systems require much faster communication to eliminate noticeable delays, e.g. when EDC requests a certain amount of fuel for injection.

They are therefore connected by a separate bus called the P-bus (Powertrain Bus). Communication on the P-bus is ten times faster than on 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.