CAN Bus while car is off?

[unref-ptr]

Here again with another inquiry.

I am wondering if from your experience while logging CAN data, does the electronics keep sending CAN messages while the vehicle is off for a long time ? Or is it always active or only when charging for example.

[projectgus]

There are some CAN messages for a little while after "Off", before everything goes to deep sleep. Same when the car wakes up (i.e. if it's unlocked or a door is opened). Some of the logs include some of this, after powering "off" with the Start/Stop button.

My understanding so far is there's three main power states:

• Always-on "memory power" things. Always powered unless you disconnect the 12V battery. Some of these modules will send CAN while awake, but then go into deep sleep and stop talking on the CAN bus if nothing else happens. I don't think there's any CAN activity anywhere when the whole car is in deep sleep.
• "IG3" - this is a relay that turns on during charging or when the car is fully On. It can be turned on by either the OBC or the IGPM (main CAN gateway). It provides power to the systems that are needed for charging. More CAN messages show up when this is on.
• "IG1" - this is the "car ignition on" relay that turns on when the car is properly on. IG3 is expected to be on already whenever IG1 turns on. Pretty much everything is talking on CAN while IG1 is on.