System overview, brief description, cars with engine management system PSG 16

Fig 1: System Overview - Brief Description, Cars With Engine Management System PSG 16

Courtesy of SAAB-SCANIA OF AMERICA, INC.

Engine control module PSG 16 is not connected on the I-bus. This system needs much faster  communication so that there are no noticeable delays when the control module requests a new amount of fuel per injection, a new injection angle or the like.

The engine control module is connected to a separate bus called the P-bus (Powertrain Bus). The communication speed of the P-bus is ten times faster than that of the I-bus.

The P-bus is also connected to MIU. MIU is responsible for ensuring that information available on one bus is also available on the other. Note also that PSG 16 has a separate K-lead to the diagnostic tool.