CAN (Controller Area Network)

CAN (Controller Area Network)








CAN was introduced on BMW vehicles starting with the 1993 740i/iL with M3.3. The CAN communication signal is considered as an input and an output between the engine and transmission control modules (among others). The CAN supplies the ECM and the EGS with all related operating data required by their operation. The CAN is a high speed bus that transfers one million bits of information per second.

Status of the following system conditions are continuously exchanged. Listed conditions are a sampling of total signal communication. Newer systems utilize CAN to a much greater extent than when first introduced.

DME: <-------------------> TCM:
- Throttle Position - Ignition timing intervention
- Engine Speed - Torque Converter Lock Up
- Engine Load - Range Selector Position
- Engine Temperature - Selected Program
- A/C Compressor On - Transmission Output Speed
- Decel Cutoff - Transmission Oil Temperature