Bumping this thread from the dead - i'm having this issue on my 2016 IS350 F Sport... but the TSB says it only affects 2014 & 2015?? So replacing the gateway ECU won't fix my problem? I'm on my 3rd battery now... I guess I'll have to keep a battery tender on it if it sits for more than a few days eh?

Anyone have any solutions? My warranty expired in Feb 2020

 

Correct, 2014 - 2015 IS250 and IS350 per the TSB so likely your ECU is OK.
When you are getting your battery replaced, is it covered under warranty from the place you purchased the battery?
I guess you don't have any aftermarket accessories installed that could cause excess drain when sitting overnight?

My 1st replacement battery (Bosch AGM) failed on me around the two year mark from installation. No aftermarket accessories for me.
Battery was covered under warranty and was replaced with a Champion AGM.

 

Hi All,

Does someone know how much current draw can be considered as normal when the car just sits and "everything" is turned off?
Factory setup, no mods, or aftermarket stuff have been installed.
A few days ago I've been replaced the OEM Panasonic battery as it got weak (after 4.5 years),
and took the opportunity to measure the current draw with the alarm system armed / unarmed state.
During this the power was supplied by a lab power supply, while the battery was disconnected
without interrupting the power towards the car.

The result was 40-50mA regardless of the alarm system armed state, which means nearly 1Ah / day
if we add the effect of self discharge. Depending on battery condition with this 40-50mA the
car should be capable to start after 30-40 days (assuming non sub-zero temperatures)
while the battery has 30-40% charge left (assuming 70Ah capacity).

So back to the initial question how much idle current is considered as normal?
...and what are the current draw figures when the gateway ECU is defective?

 

So my battery die again last Saturday and this would be the first one die after gateway ecu change which was done back in dec 2018 and this one marks the 6th battery replacement since 2015.

when I dropped off my car this morning my new SA just ripped me a new one. She said “it is normal to replace battery every one or two years. Sometime people replace it twice a year.”

 

IMHO it is not normal to replace the battery twice a year or even one or two years, especially for a daily driven car.
When batteries needs to replace this often that may suggests

• excessive (parasitic) drain
• defective charging system (under or overcharging)
• inappropriate battery (e.g. not start/stop compatible)

In case if the car is not in daily use a battery tender can prolong the lifespan of the battery.
For example after a two week sit the car should be able to start, but charging current provided by the alternator will be excessive,
reducing the battery life. This is also true after a jump start.
Due to the epidemic situation my car often sits 5 to 10 days without starting. In my case the battery needs 16-24 hours of slow charging (1A or less)
to completely top up, judging from the current draw. The last phase (a.k.a saturation) might take 6-8 hours,
this is when the voltage is already constant, and charging current drops below 200mA.

 

You definitely have an issue if you're using you IS on a regular basis.
And no, it's not normal to replace a battery more than once a year, or even more than once in 3 years.
Even in states with constant scorching heat you should be able to squeeze 3 years out of a battery.

Do you have any paperwork from 2018 that shows the Gateway ECU part number that was installed?
Does your IS have any aftermarket electrical accessories installed?

 

So this is my story.. everything was working perfectly.. went out tonight to get some food went back home, 10 min. later I decide to head out again and the car won’t start. It turns on lights everything looks normal, but when I press the Start button a rapid clicking noise takes over and I just press it again to stop it, dont want to damage anything.

*video attached*

Car warranty expired on 12/11/2020 🤦🏻‍♂️, the car has 49,936miles . Never had a prob with the car except a dash clock issue where it was shifting the time lately and when I took it to Lexus they said they checked the battery ( original battery) and it was low and decided to put a “new” one. This battery swap was on 09/2020. Since then, the car was working as usual (perfectly fine) except for tonights event.

Im hoping this to be a bad “new” battery issue as batteries don’t die that quick, since my car is electronically OEM, except for the dash clock which got replaced. I haven’t checked the voltage, but will check tomorrow.

I dont trust dealers for out of warranty service, but since this would be the first issue out of warranty ( it just gives me anger because it happened 1 day after warranty expired ) i want to check what they say about that 3 months old battery and if they will replace it. I dont believe the car has electrical issues, never got a single problem with the oem battery and I check for codes or warnings monthly and nothing.

 

battery should have an individual warranty on it.

 

yes that was the case, this morning i took my dmm turned ignition on measured the battery and the proof was there, 10.1v , so not even the screen was working. A friend came and helped to jump started, took it to the dealer they put a new one and found the old battery was leaking, a 3 months old battery leaking ... well it is what it is, I tell them the screen stopped working as well last night and on the phone he said everything was working again. When I got the car back the Lexus rep can’t turn on the screen .... said it was working earlier... yeap .. so Im gonna take it back on Monday for the screen..

If the screen issue is a memory loss due to low voltage , any idea on how to work it? if I press the power button I can hear the beep sound when the system comes up, I can receive calls through Bluetooth with no issues , but black screen , not turning on. Cant hear radio, AC buttons working fine.

 

I believe black screen is a common issue related to weak/dead batteries. I recall the solution being to disconnect the battery for 15 minutes and then restarting. You can search the forum for threads related to the issue

 

thanks mate, i found a discussion on the topic and already unplugged the battery, waiting the 15 min , ill post the result.

 

Worked perfectly! My screen is back!

Im very surprised the dealership didn’t performed this simple procedure and hand me the car like that.

As I always do, thanks for those who responded and helped! This forum is amazingly helpful.

 

HI
man this sucks, i had my eye set on a '15 IS350 f sport, hopefully they remediated that for the '15 model year.

____________________________________________

P/s thay pin iPhone at viet nam and Pin pisen iPhone

 

Happy 7th battery replacement, battery built date sep 2020, installed oct 2020, time of death aug 2022.

 

Still on the original battery - 2016 IS350