BUS TYPE BACKGROUND
established at least once
since the start of the CAN
bus check, but
currently not occurring.
Either of the following:
If a gateway function
equipped ECU cannot
communicate, sub bus
and ECUs connected to
the sub bus will not be
If no ECUs are connected
to the sub bus, "There is
no system found on the
Communication Bus" will
Gateway function equipped ECUs relay signals between the ECUs
connected to the different buses.
*1: ECUs that are present in the vehicle but are not displayed on
the CAN Bus Check screen.
*2: Gateway function equipped ECU that does not memorize the
sub bus ECUs that are connected to it.
*3: Gateway function equipped ECU that memorizes the sub bus
ECUs that are connected to it.
The example of the CAN Bus Check screen in the illustration
shows the result of electrical noise on the CAN bus which is
caused by an open in a CAN branch line of ECU D (output from
the other branch line is unstable) and the communication of ECU
C is also unstable. In addition, in this example, ECU C is equipped
with a gateway function. Therefore, communication is also
unstable between the sub bus ECUs of ECU C and the V bus.
The example in the illustration shows that ECU D is not displayed
on the CAN Bus Check screen. This indicates a more significant
communication stop. In this case, a communication stop of ECU D