General Specification Electrical Function gmw3110 General Motors Local Area Network Enhanced Diagnostic Test Mode Specification

5.2 Communication State Diagram Based On Version 1.5 of GMW3104. 
Figure 9 and Figure 10 were taken 
from GMW3104 to provide a visual aid in understanding the possible communication states that exist in a 
node. The COMM_INIT and COMM_KERNEL_ACTIVE states are the states where a node is either capable of 
communications, or in the process of initializing the hardware and software necessary to become capable of 
communications. A node which is not in the COMM_INIT or COMM_KERNEL_ACTIVE states is not capable of 
communications and must enter the COMM_INIT state (to initialize the communications hardware and 
software) prior to communicating with other nodes on the vehicle or an off-board tester.
 
The following sections of this specification describe what takes place in the COMM_INIT and 
COMM_KERNEL_ACTIVE states relative to diagnostics. For more detailed information on these states or 
the other states in the figures (reference GMW3104). 
Figure 9: GMLAN Node Communication States 
COMM_INIT
COMM_INIT_COMPLETE / 
COMM_ENABLED_TIMER := 8 sec;
COMM_SHUTDOWN_STATUS := Disabled
ECU_READY
COMM_SHUTDOWN_CONFIRMED 
and
[COMM_SHUDOWN_STATUS := Enabled]
ECU_IN_STANDBY
STANDBY_OK
ECU_EXECUTING_RESET
RESET_COMPLETE
ECU_POWERED
[POWERED]
[not_
POWERED
]
LOCAL_EVENT_NO_COMM_REQD
ECU_UNPOWERED
RESET
ECU_ KERNEL_ACTIVE
B
U
S_
WA
K
EU
P_
MON
IT
O
R
_A
C
TI