I have 2001 LS430 with 169,000 miles on it. About six months ago I was waiting in a store parking lot on a friend. I had turned off the engine and was listening to the radio with the key on ACC. When she came out and I started the car to leave it wouldn't start, it acted as though the battery was dead because it just clicked when trying to turn over and the automatic steering wheel moved very slowly when I exited. I got a jump and the car started right up and everything worked fine. The battery was over 4 years old, so I figured I just needed a new battery and went to an auto parts store and they installed a new one. Well, the same thing happened about two weeks latter, I went back to parts store thinking I just got a bad battery, they tested it and it was fine. I took it to the local Lexus dealer to find the problem and they said everything tested fine and there were no problems with the battery or the alternator and they couldn't find what the problem was. They said if it happens again don't try to start it and have it towed in so they can diagnose it while it was having the issue. Well, soon after it done it again and I did what they said. Got it there, they hooked it up to their testing equipment, tried to start it and it starts right up. Their equipment shows everything working just fine. This happens if I listen to the radio while parked, it also happens when I clean the car and leave the doors open while cleaning the interior. All I have to do is let the vehicle sit for about a half hour and it starts up no problem at all. In addition to Lexus, I have taken it to a shop that specializes in Japanese imports and they cant find the problem.

Has anyone else experienced this issue and figured out what the fix is?

 

It sounds like your battery isn't at full charge. Check your battery cables for corrosion. It will look like a greenish powder where the insulation starts. Corroded cables won't flow enough power to keep the battery fully charged. Also check all grounds and the alternator wiring for the same. If you have a voltmeter check the alternator output voltage at the stud on the back of the alternator and compare it to battery voltage, both while the car is running. If they aren't very close to the same you are losing power in the cables or connections.

 

Sounds like you have parasitic draw. Disconnect the negative side of the battery. Put a multimeter to measure current between the battery and the disconnected cable. Put the multimeter on the milliamperes setting.

current measured should be low, probably less than 50ma. If higher, something is still on in the car causing the battery to lose voltage.

 

This has happened to me 10 years ago. I now never use car in ACC. If I ever wanted to wait and listen to music, I keep the car running. No problem since then.


I think LS draws too much battery to be using music on ACC.

 

Battery is fine, new in March of 2020. Had it tested where purchased when problem first started. Also, Lexus dealer and an independent import shop both couldn't find problem. I'm sure, at least hopeful, they would have checked those things. I appreciate the reply though.

 

This is an interesting topic of course heightened with COVID 19. Unexpectedly, my wife's car was dead after 4 days, out of nowhere. And because it had a Costco battery, I didn't have to really worry, just got a new battery no questions asked under warranty. It was 2 years old.

Thing is, there is no doubt--car could not start no juice. 8 volts. I could not jump it from the terminals under the hood, had to do directly to the battery inside the car. I WISH I LOAD TESTED IT AT THIS POINT, for my own records and knowledge.

Once I jump started it, we drove around, for maybe 20 min. Put it back, and removed the battery. It tested fine.

Why the last sentence is puzzling, is my buddy's mom's CR-V had the same thing happen. AAA tested the battery fine after jumping it. Took to Honda dealer, no issues to be found. Battery never replaced, been fine ever since.

I would agree with parasitic draw, just hard to pinpoint. It's not as easy as knowing lights left on, etc. Meaning, once that cause is removed, car runs fine and battery even tests ok.

Good luck.

 

I also experienced the same issue recently after listening to the radio for half an hour. Only accessory switched on was the radio. My battery is near new and always starts fine. I remember reading other similar discussion on this forum about the 3rd gen. I get the impression it must be an issue in the design of 3rd gen electrics.

 

I really appreciate all the reply's, keep them coming, I'm making note of them and plan taking the vehicle back to the dealer and have them check the suggestions I'm getting. Probably be another few weeks before I take it in. I'll update here the results.