Advanced Bus Systems

The launch of the E65 brought about new technological innovations which required some advancements in bus technology. Fiber Optics, newly introduced to BMW group vehicles, allow for a larger amount of data transfer at a faster rate.

There are 2 new Fiber Optic Networks used on the E65. These new networks are MOST (Media Orientated System Transport) and byteflight. MOST is used for information and communication systems such as navigation, audio and telephone. The new byteflight system is used exclusively for the safety system (ISIS).

In addition to fiber optics, copper wire bus networks were also modified to meet the needs of the new technology. New networks such as PT-CAN and K-CAN enhanced the existing CAN bus and K-bus already in use on earlier models.

Example - E65 Bus System 

Fig 1: E65 Bus System Chart

Courtesy of BMW OF NORTH AMERICA, INC.

The K-CAN (Body Controller Area Network) replaces the single wire K-bus used on earlier models. K-CAN is subdivided into two sections: K-CAN System and K-CAN Periphery. K-CAN S and K-CAN P use the two wire twisted pair configuration. The communication speed has also been increased to 100 Kbps.

The PT-CAN system replaces the existing CAN system. PT-CAN differs from the existing CAN system by using an additional KL-15 "wake-up" wire. Communication speed remains the same at 500 Kbps.

New Sub-Bus systems have also been added to provide "local" communication to the larger networks. There are several Sub Bus systems on the E65, these include the Driver's door P-Bus, the Engine LoCAN, Telecommander CAN, M-Bus DWA K-Bus and the BSD interface. These systems will be discussed later in this course.