daveo4EV
Well-Known Member
- First Name
- David
- Joined
- Jan 28, 2019
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- 160
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- Location
- Santa Cruz
- Vehicles
- Cayenne Hybrid, 911(s) GT3/Convertable
- Thread starter
- #31
once the 12V is dead I'm increasingly of the opinion the vehicle bus is isolated - the ODBII charger wot' provide enough power to "run" the main 12V computer - so it will never wake up - and you're not actually charging the 12V battery because it's "offline" and isolated behind a relay
but that's just pure speculation on my part - see diagram below - you need enough power on the 12V bus to power the main computer to trip the relay to reconnect the 12V battery - not clear to me the ODBII port can accept enough power for that to happen…when the 12V "dies" it goes offline behind the relay for it's isolated safety…
but this is all pure speculation on my part - but 12V power to the "jump post" is the recommended technique to wake the car up at the factory and as part of PDI when dealer receives the vehicle.
[picture deleted - see post #33]
but that's just pure speculation on my part - see diagram below - you need enough power on the 12V bus to power the main computer to trip the relay to reconnect the 12V battery - not clear to me the ODBII port can accept enough power for that to happen…when the 12V "dies" it goes offline behind the relay for it's isolated safety…
but this is all pure speculation on my part - but 12V power to the "jump post" is the recommended technique to wake the car up at the factory and as part of PDI when dealer receives the vehicle.
[picture deleted - see post #33]
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