THEORY OF OPERATION - CONTINUED
TRANSMISSION - CONTINUED
Other Outputs. Machine ECM also sends information to engine ECM via CAN data link. Machine ECM also sends
information to dash panel cluster and diagnostic connector via CAT data link.
Machine has two data links: CAT data link and CAN data link. A data link is not a visible component. A data link
consists of internal ECM circuits and connecting harness wiring. Data links are bidirectional, meaning they allow
ECMs to receive and send information.
CAT data link is an input and output of ECM. CAT data link is connected to ECM at connectors J1-10 and J1-20.
Machine ECM communicates with engine ECM on CAT data link.
CAN data link is an input and output of ECM. CAN data link is connected to ECM at connectors J2-67 and J2-68.
Data link is designed to communicate with other ECMs through machine harness. Machine ECM communicates
with engine ECM and instrument cluster on CAN data link. Engine ECM does not communicate directly with
instrument cluster. Engine information is sent to machine ECM. Then, machine ECM sends information to instru-
Electronic Technician (ET) also communicates with other ECM modules through data link. ET will list other ECM
modules and available diagnostic information. Information on both data links is available to ET via diagnostic con-