Devices plugged into my 2014 VW EOS diagnostic port quit after a day of so of being parked without the engine running.
Could it be that the network goes to sleep to save power? How can I test for this?
I'm surprised it takes a whole day. I would have thought within an hour the BUS would be asleep, after that I would imagine it would only be modules waiting for remote inputs i.e. remote transmitters, passive entry, door buttons / switches.
Hi
Two different issues here
1. The live at the EOBD is permanent live, so never goes to sleep
2. As Mark said, depending on model/year etc the different BUS will go to sleep, in anything from a few seconds to maybe 40minutes, say 60minutes as an outside. This is perfectly normal.
If you device is drawing excessive current from the Live then it'll drop battery voltage to possibly a level below it's own minimum. You could check this by leaving a trickle charger attached.
But this is all a little missing the point, why do you want to monitor the BUS when the car is asleep? Yes, I realise there are some reasons, but would like to hear yours/your deivce?
Have you tried pulling the BUS on to the scope to see things?