Cutlass V6-191 3.1L VIN M SFI (1998)
Body Function Controller: Description and Operation
Body Function Controller Communication
Data Line Communications
The Body Function Controller (BFC) communicates on two separate data lines, Class 2 and Serial Peripheral Interface (SPI).
Class 2 Data Line
Class 2 data is a higher speed data transmission. To control serial data line traffic, Class 2 uses the peer to peer method along with message arbitration to
manage data line traffic. The control modules on the Class 2 data line are:
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Body Function Controller (BFC)
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Electronic Brake Control Module (EBCM)
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Powertrain Control Module (PCM)
Serial Peripheral Lnterface (Spi) Data Line
The Serial Peripheral Interface (SPI) is a three wire interface connecting the Body Function Controller (BFC) to the Instrument. Cluster, which allows
for them to exchange information. This interface is a synchronous serial data link where the Body Function Controller (BFC) is the master and the
Instrument Cluster is the slave. Because of the need for modules on the different serial data links to communicate with each other, the Body Function
Controller (BFC) acts as an interpreter, or master, for data communication between the Class 2 and Serial Peripheral Interface (SPI) data lines.
