Nospinzone

There can be very large difference in the electrical load from ACC to IG-ON.

I remember when leaving the key in the IG-ON position would burn out the points.

Anyone here younger than 40 is wondering what the hell are "points"!

Shibumi1

one thing no one has seemed to mention.... once a battery has been depleted (past 50%) it NEVER fully recovers unless ur a millionaire an have located a super Ni-Mh or Ni-Cad batt..

after a 50% depletion the average new ""full charge" is now only 80% of actual full..and each time the batt dies (which becomes easier each time) that % lowers... an unfortunately a load test may not show this. which is what the dealer uses to test the batt.. problem is that newer engines require a lot less (actual) power to start.. an shorter crank times.. but if they do an extended load test 20 secs or so. it would show the true state of a batt..

you can also do a chk of ur electrical system to see if any loads exist over the recommended factory limits... any auto electric shop should be able to help...

but definitely buy a new batt so u dont get stranded somewhere.....

Craig B

That makes a lot of sense. I've never left my vehicle on in the on position. I have left it on in the ACC position and had it shut off in about an hour. I don't drive my LS 460 much, so I keep it stored on a battery tender plus. It sits in my garage the entire winter. I drive my SUV in the winter.

Regards,

madlad

Good info people, but doesn't help. Went to the dealer yesterday. Service tech had no answers. Took the vehicle home, parked in the garage, with the stalk set for "auto." Turned off the engine, locked the doors, and waited to see how long it would take for the headlights to go off...they didn't. Moved the switch to "off" position. Clearly, the engine was completely off, and the internal lights were out within 15 seconds. The new battery has 850 cranking power, so it's not a cheapy. I'm thinking its a sensor problem of sorts. Nothing on the dash to block the sensor. Problem with the dealer is, if you can't replicate the problem in their presence, you don't have a problem.

JFNash

I'd argue the lights are a matter of settings/configuration. I doubt that lights would deplete your battery as from what I understood the battery would still discharge even when lights are off.

Hmmm. Get on the secret menu and observe the readings (battery voltage and any relevant reading). See if you can get a hint from there.

To access the 1st secret menu, press Display, then on the touch screen upper left corner, lower left, upper left, lower left.

To access the second secret menu (where you can get many many readings), enter the 1st secret menu. In the top of the screen, click the black (MENU) button. Then upper left, lower left, upper left, lower left, upper left, lower right.

HTH.

MikeE12345

I must give this a look see. Is it obvious how to exit the "secret" menu - I'd hate to be stuck there.

Thanks,
Mike

jmcraney

Sir, I can tell you have lost confidence in your car because of your recent experiences with the discharged batteries. Before you hire an Exorcist I need to give you some more information to consider.

The headlight "Auto OFF" feature begins its timeout from when one of the front doors is opened. So, if you conducted your auto-off test without opening one of the front doors - by waiting in the drivers seat - then the headlights will not automatically turn off and will probably stay on until the battery is dead, or you conclude that they will not turn off and decide to move on. If you conducted your experiment by reaching through an open window, with the remote key in your hand and cycled through the ACC/IG-ON/IG-OFF, leaving it in IG-OFF with the headlights on in the Auto mode, you would get the same results - eventually a dead battery.

This is a common design feature in most cars that have the auto-off mode and has been in use for many years.

It's another one of those "been there, done that" pieces of knowledge for me. Several years ago, when my first Lexus, an LS400, was a couple of weeks old I went out to the garage to enter some presets into the radio. I sat in the passenger seat and reached across and put the key in and turned to ignition-power-on and did my presets. When I finished I got our of the passenger door, the headlight were on, and I went into the house expecting the auto-off feature to turn the headlight off as it had been doing so faithfully for several weeks. Well, the next day the battery was dead. On that model only the drivers door opening would initiate the auto-off timeout. Because of that experience, checking to be sure the headlights would go off when the passenger door was opened was one of the first things I tested on my LS460. The auto-off feature works on the LS460 if either front door is opened.

Because of your description of the difficulty that AAA had starting your car I continue to believe that that event was related to accidentally leaving the ignition on.

I hope that you don't find my suggestions argumentative. They are not intended that way.

JFNash

Just press the Display button for 5 seconds and you'll be out.

edarte

I continue to be amazed with the complexity of the algorithms that Lexus uses and with jmcraney's knowledge of same.

cmasten

Funny! and totally true, we all think that he may have been Shakespeare in another life :-)

madlad

To jmcraney. In both instances, I had completely exited the car, had the drivers side door closed and locked. (Yes, I lock the car even in the garage). I then stood in front of the car. The car was completely off and the fob never left my pocket. The headlights didn't go off until I re-entered the car and put the **** on the stalk into the "off" position. I'm going to see what I can find from the secret menus. As an added note, I heard a slight whirring/whistling sound from the front while the lights were still on. It stopped as soon as I switched the **** to the "off" position and the headlights went off. I appreciate your comments and you appear to be pretty knowledgeable about the Lexus. Thanks for your inputs.

jmcraney

Houston (and Lexus), "madlad" has a problem with his car!

The whistling that you hear is balast noise from the balasts for the HID headlights. Proves your hearing is good - some can't hear frequencies that high.

iceman76

Did he help devise the algorithms for LEXUS?? It is quite phenomenal the amount of info / help he gives on the cars.

cmasten

It would seem that your circuitry for the auto feature for the lights is the malfunction. That is easy enough to show the dealer and have them replace those components, there is a timer circuit that is attached to the stalk. I could look that up in the service manual, but your symptoms are easily recreated and the dealer can fix it.

randomwalk

your headlight switch is set at "auto" and not at "ON" right?