P-bus and I-bus

Fig 1: Identifying P-Bus And I-Bus D1PUZZLE

Courtesy of SAAB-SCANIA OF AMERICA, INC.

Fig 2: Identifying P-Bus And I-Bus

Courtesy of SAAB-SCANIA OF AMERICA, INC.

Fig 3: Identifying P-Bus And I-Bus PSGPUZZL

Courtesy of SAAB-SCANIA OF AMERICA, INC.

All Saab 9-3 M01 are equipped with the Trionic T7 engine management system. The bus system is therefore almost identical to the one fitted on the 9-5.

The bus system on diesel cars with EDC15 and diesel pump is unchanged from M98 1/2 and on cars with PSG 16 from M01 1/2.

The two diesel engine systems EDC15/diesel pump and PSG 16 are not connected to the bus however. These systems require considerably faster  communication to avoid any noticeable delays, e.g. when EDC or PSG requests a certain amount of fuel 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.