The HS-
CAN bus on the Fiesta is a 500kbps, 11bit bus, that presents on the standard pins on the OBD2 port. HSCAN+ is pin 6, HSCAN- is pin 14. The bus needs a terminating device at each end - teh
PCM is at one end and the IC is at the other.
HSCAN Broadcast Messages:
PCM, IC,
ABS, (EHPAS)
HSCAN Diagnostics & Programming:
PCM, IC, (EHPAS)
The MS-
CAN bus on the Fiesta is a 125kbps,11bit bus, that presents on 'Vendor Option' pins on the OBD2 port. MSCAN+ is pin 3, MSCAN- is pin 11. You can't get to these pins using a normal cheap ELM327 tool, unless it has been modified to be 'switchable' between the two. J2534 tools, if the full API is implemented, can switch pins using an API call. So too can voltage be applied if needed.
MSCAN Broadcast Messages: IC, GEM, ACM,
RCM, (EATC)
MSCAN Diagnostics & Programming: GEM, ACM, (EATC)
The ISO9141 is a 10.4kbps bus that presents on the standard pins too - the K Line on Pin 7.
ISO Diagnostics & Programming:
RCM,
ABS
The names and the modules and their addresses for diagnostics and programming are as follows:
IC = Instrument Cluster. Target ID=0720h on both HSCAN and MSCAN
GEM = Generic Electronics Module. ID=0726h on MSCAN
ACM = Audio Control Module. ID=0727h on MSCAN
EHPAS = Electro Hydraulic Power Assisted Steering. ID=0730h(?) on HSCAN. To be confirmed.
EATC = Electronic Automatic Temperature Control. ID=0733h(?) on MSCAN. To be confirmed.
RCM = Restraints Control Module. ID=58F5h on ISO
ABS = Antilock Brake System (+ESP). ID=28F5h on ISO.
Each module sends out a series of broadcasts, and those broadcasts contain various bits of information that can be read by other modules. An overview of the broadcast messages, the source and what is contained in them are listed in a link in a previous post to a google sheets document.
Luke