12v battery died parasitic drainage AM1 fuse?

Do you have a SKS smart key? If you turn that off, that may minimize the draw

 

A little clarification is necessary, I think.
As soon as you open the door, some (most?) of the computer systems "come alive" in preparation for "starting".
If nothing actually happens, they will go to sleep again after some time.....a minute or two ??
If you keep doing "things", they will stay "alive"......and this is not necessarily parasitic drain.
To actually measure the parasitic drain, all doors, buttons and switches must be in the "off position" for that de-activation period.
I think it is only a couple of minutes.......but a half an hour should be safe.

 

1. I am aware of an AM2 fuse, but not an AM1 fuse.
2. The most likely reason for abnormal quiescent current draw is a relay stuck in the closed position.
3. It would help if you are able to observe a circuit which remains powered up when it should not be, while the car is IG-OFF. For example, if you saw the multifunction display was on, or the cabin ventilation fan remained on. That would provide a good clue about which relay to look at.
4. Lacking such clues, you would need to use the electrical wiring diagram to look at all systems which receive power via the fuse in question, and look for relays downstream from that fuse. Tap each such relay with a screwdriver to see if that causes the relay to release. If that doesn't help, then you would need to remove each relay to see if that makes a difference.
5. When the Prius is IG-OFF and locked, the quiescent current draw should be around 0.02A after the various systems settle down and assuming the Smart fob is a reasonable distance away.

Good luck.

 

perhaps you just had a 'senior moment'. i'm finding them more and more frequent.

 

This is very interesting. The newer 2G Prius do not have an AM1 fuse. It was removed from the 2006 electrical wiring diagram, for example.

It appears the only job of AM1 is to provide a permanent 12V source to the power source control ECU. If you look at the four snapshots of the AM1 fuse, in all cases they show the same circuit where the AM1 fuse feeds power to the AM1 terminal of the power source control ECU. That is probably why it was eliminated in subsequent 2G models.

When you were pulling fuses, did you by chance try the AM2 fuse and DOME fuse to see if their removal would result in a current reduction? I suggest you try to find other fuses which have an impact, as AM1 isn't doing much.

If you really were to find that AM1 was the only fuse which drove a quiescent current reduction, that would lead me to believe the power source control ECU was having a problem. However if true this would be an exceedingly rare event.