My new to me 2013 LS 460 AWD has lived in my garage all of two months but its well documented history shows that it has eaten 5 batteries in the 10 years it has been in service. As of yesterday it added one more dead battery to its tally as the sixth battery survived only 8 months before being destroyed. It has been a Lexus owned vehicle up until a local used car dealer bought it in 2020 so all the batteries (except the last one) have been replaced by Lexus dealers in southern California. It has 70,000 miles the clock.

With the car stopped, engine shut down, and the transmission in park there is a small sound of n electric motor running coming from the center of the dash. As far as I can see there is nothing turned on yet the noise continues. It seems that there is something that is not being turned off by the usual exit protocol. Is anyone else having this issue? Does anyone have advice on how to stop this?

Don

 

I know the sound you're hearing, I believe it's the hard drive in the nav unit and not a servo for the hvac.
My 2013 makes that noise with key on/engine off and is normal but mine shuts off when the ignition is turned off. There is a TSB for a flash of the Electric Power ECU for the battery going dead but doesn't list any specific causes for it.

I doubt this would be covered for you anymore but you could try it.

 

There's also a common issue with the door light switch. The plunger gets intermittent with drawing current after it's closed. As you know, intermittent issues can be hard to duplicate for diagnosis.

 

HAH! The hard drive on the nav. That's a very close match to the small sound that this makes. I'll check out if if shuts off when the switch is cycled. But first I have to install the 6th battery in my machine. Thanks for the quick reply.


Don

 

I'll check this out too. Many thanks

 

I'll check the door light switch out too. Many thanks.

Don

 

The Technical Service Information Bulletin tip (L-SB-0061-13 Rev I, 9/17/13) you furnished may be the key here as my car is indeed an early 2013 and the VIN matches the listing where the reprogramming of the Electric Power Control ECU is described. Once I get the fresh battery installed I will zip on over to the Lexus dealer and ask them to use this procedure to see if it will address the frequently discharged batteries that this car has suffered over the years. Consuming batteries each 18 months just does not seem acceptable. The most recent battery that is now dead is #6 and was only in service for 8 months before it was destroyed. The car's history showed that it sat still for long periods.

Crossing my fingers here.

Don

 

If you have any problems getting the flash you could get a battery tender, noco or ctek or whatever brand you want. mine fit the ser# but I wasn't having problems...tried to get the flash anyway but the dealer I went to said the tsb was too old and couldn't do it.

 

Do you understand that the LS460 consumes energy from the battery when the engine is not running? After it sits idle for a while all the batter’s energy is depleted. Just because the battery has no energy does not mean that it is defective.

 

Yes these cars will draw more power than most when just sitting, if I leave mine off the ctek tender the battery will drop to around 12.3 after 2-3 days.If left on the tender it stays around 12.6 so after a week I might get a slower than usual crank.

If it went to the dealer there is no way they wont replace a battery when it presents as a no crank or low load test, no money in charging batteries.

 

hmmm I just replaced my battery... I wonder if this is why...

 

I removed the 8 months old battery that would not start the car and let it rest a bit. The voltage produced by the battery sitting on my bench now reads 11 volts. That is pretty flat as it is supposed to be about 12.8 volts. New battery arrives tomorrow. I plan to keep it on a battery maintainer as I did with my Rolls once the new battery is in place. The interesting thing is that there was absolutely no warning of an impending failure. The previous day it was fine and the next day it was not. I've not had much luck with this car in the two months I have owned it.

Don

 

Sometimes batteries don't give you much warning especially if it sits alot, still a minor problem.

 

The battery tender should help a lot. A fairly simple diagnostic would be to put an amp meter at the battery to measure the drain when car is turned off. Then you start with the main fuse block, pull one fuse at a time and observe any change in the meter. Open a beverage and repeat. You'll likely find a circuit that's drawing an excessive amount. Then you can have that circuit/system checked by a shop. Hope you can narrow it down quickly and let us know what circuit is amiss.

 

Just an update on the issue of repeated destruction of batteries on my 2013 LS 460. Lexus of Tacoma, WA today confirmed that the software for my Electric Power Control ECU had never been updated in spite of the fact that the Lexus Technical Service Information Bulletin from September 17, 2013 (L-SB-0061-13) had called for it to be done. The issue was that the original software had a glitch that discharged the battery if the car was allowed to sit more than 50 hours. My new-to-me car had been owned by 4 Lexus dealers in Southern California since it was new and apparently not one of the dealers bothered to update the software as called for in their own TSB. Really guys? Since then the car has destroyed 5 batteries every 8-18 months or so since new.

But that omission was easily put aside when the TSB was provided to a real Lexus tech. The updated software has now been loaded. They also checked for phantom electrical drains when the car was shut off. Only a drain of 0.03 Milli-amps was found = trivial. However they did recommend keeping the car on a battery maintainer if it will sit idle for more than 5 days. Does this recommendation sound familiar?

This advice nicely corresponds with what the folks replying to my message on this Forum had said earlier. OK troops, Ya nailed it!!!! Thanks for the support.

I hope that addresses this vexing issue.

Don Elliott