05 GS300, 1st battery used 4 years and replaced for free, dead again 4 years or this month, both battery are 8yr warranty Toyota one. 3rd battery bought in wheel works.
I replaced the battery after car cannot start 3 times. If I don't drive for 5 days it cannot start, yet ok if leave it only two days. New third battery acts the same. Each drive is only 30-45miles. Both yesterday and the day before yesterday I drove 30-45miles on free way, this morning drive out garage (20feet), disconnect battery and voltage is only 12.2V.

I measured the idle current:
1. with key inserted (not turned, if no key it alarms), remove negative battery terminal and add an amp meter, static current is 3.1A, ECU-B1 itself is 1.2A.
there is a click whenever battery connected, then I found pull out EFI fuse the current is 1.28A, pull out again ECU-B1 I get 0.17A. Pull out EFI relay and it is ok, but relay control output is engaged, so plug in relay it turns on and gives click sound.
2. remove amp meter and reconnect battery, pull out the key, measure the relay control output still there but relay not engaged..

Important correction of measurement:
when battery is charged, insert key and open engine hood, then pull out key. following battery cut off/on won't trigger alarm.
measured current is total 400mA, ECU-B1 itself is 350mA. EFI relay not engaged.

 

Parastic draw should be no more than 70 mA on our cars.

 

which car? did you measured or just believe? how you measure it to get rid of alarm? I know people says 20-30ma. But on my GS300, even I pull out ECU-B1 and EFI there is still 175ma. May be key-in measurement is not accurate, but EFI relay engage seems odd.

I corrected my measurement in 1st floor.

 

i measured it from my GS430. Keep in mind our cars have alot of KAM component since it's a luxury car compared to regular cars. So, 70 mA is reasonable, anything thing more would be too much.

 

Did you test it with the battery terminals taken out? I've posted before i believe, that batteries sometimes show symptoms of parasitic draw when it's on it's way out.

 

yes I taken out and put a meter in. this is a new battery.

 

Thanks! GS430 is 3rd gen. My new battery is a little high capacity than previous Toyota battery Lexus changed for me, but not sure original battery capacity.
Looks like ECU's 350mA is too big, any body know a simple fix?

 

My gs430 is 2nd gen.

 

you are right, then mine definitely has problem. thanks a lot.

 

Alternator?? Or you must have a short somewhere..

 

the problem is when total 400mA, pull out ECU-B1 it drops to 50ma. so I think alternator would not be a problem. I suppose alternator is not controlled by ECU.
any body has ECU pin out? how many ECU in the car?

 

I'm having the exact same sympton as you desribe. If I may, how did you resolve the problem?

 

You may not get an answer. It's an old thread.