Battery killer & memory seat won't set
 

I'm posting this so that if anyone has mysteriously had their battery die after being parked at night OR when getting into car and memory seat button fails to reset seat I have an explanation.

I've had both issues and I was able to identify the cause as a defective door closed switch on the door post.

Occationally after I get into my car after my wife has driven it my memory seat button on the door fails to adjust the driver seat. Also I have found that occasionally my lights remain on after parking in the garage at night if light switch is set to auto mode.

It seems that the memory seat button requires that the car senses a door open and the headlight auto off timer requires the car to sense a door open and close.

My driver door switch located behind the rubber cap on the door post is Intermitant. If my memory seat will not set the seats I just twiddle the rubber cap and then seats will reset when I select my memory position button on the door.

The dealer is replacing both driver and front passenger switches.

JR

JR,

The cars have so many interlocks it is sometimes hard to keep it all straight.

As for the "light switch set to auto mode": the feature that automatically extinguishes the external lights after the ignition is turned off has no operator controls, is autonomous and is always enabled for all lights-on modes.

And there are some important points to keep in mind about the seat memory.

1. As long as the car is in Park, when the door is open the seat memory will work whether the ignition is off or on.

2. The seat memory will not work when the door is closed, if the ignition is off. (If you were in the habit of setting the seat memory with the door open before you turned the ignition on and you occasionally changed your timing to doing it with the door closed and the ignition off, you might feel that there was a malfunction.)

3. As long as the car is in Park, and the ignition is on, the seat memory will work whether the door is open or closed.

Jiggling the switch and watching the light on the bottom of the door flicker is probably not an indication that the switch is defective - it is the nature of those types of switches. Mine do that and i don't have any problems.

And with all that said, it is certainly possible that one of your switches is defective. I don't recall ever seeing a report of a defective door switch, so that sort of thing is rare.

Thank you for sharing you experience with us.

Mr jmcraney,

Thanks for your reply. Your knowledge of the logic circuit sequence was very helpful.

My background is 45+ years in the field of Avionics support, 3rd level factory field tech support and eventually Field Manager of Technical Support for a major computer and high speed printer company. I can verify that both door open switches on my LS are intermittent. The dealer service advisor told me that while this is not a common problem it is also not uncommon. When they get a car with the phantom dead battery after being parked in the garage, these switches are one of the first suspects.

Pictures are worth 1000 words. Look at the attached YouTube videos I just took. You can see the car sensing the open door either delayed or not being sensed at all.

1st video
1st time the door open curtesy light is delayed coming on
2nd time only way to get it to come on is to twiddle the door switch


Next video
1st time light comes on normally.
2nd time light is delayed coming on
3rd time light does not come on until I twiddle the switch

In my car, Often when door is open the memory seat will not work, that is when the door switch fails to signal an open door.

My wife has seat set full forward when she drives. I am 6' 1" and 250 lbs. It is not possible for me to get into the car when the driver seat is set for my wife. :) Therefore I don't have the option of getting into the car and closing the door.


My wife has done this as she can get into the car when it is set for me BUT as I stated above I can't fit into the seat when set for her. If I were to accidentally select the #2 memory seat position when seated in the driver's seat, I get my knees crushed and steering wheel imbedded into my belly. That really hurts.

JR

One other observation that confirms a defective door open/closed switch =
I can occasionally lock the doors with the remote fob WITH THE DRIVER DOOR OPEN.

Yes, but I don't think you can extinguish the headlights with the remote fob when the door switch is stuck in the closed position.

JR,

Brillient! Brillient! Brillient!

Your skillful use of modern technology to show us about the switch failures you are experiencing will help more people than you probably realize. This site and the discussion threads here are read and followed by Lexus owners all over the world.

Your qualifications are impressive and we are lucky to have people like you who are willing to help us. Thank you!

Normally we don’t think about switch failures like yours, where the switch is stuck in the position that indicates that the door is closed, as problematic, more of a nuisance. The kind of failures that we usually regard as a problems are the ones that keep the interior lights on or the warning signals on because the switch has failed in such a way as to indicate that the door is open. Any failures of these switches is rare and since you have experienced two failures then that may be indicative of some sort of mass problem that is related to the switch manufacturing process.

We have seen lots of phantom battery failure reports in our discussions over the past few years. Most reports tell us that the dealer replaced the battery leaving the impression that the battery failed prematurely. I have never been able to accept a premature battery failure without some further investigation to insure that the battery was truly bad and that is usually done by charging the battery and then testing the specific gravity of each cell with a hydrometer. We have no way of knowing if Lexus is doing that behind-the-scenes failure analysis but I doubt it. And your comment that your dealer is aware that the door switches are a problem is the first I have seen regarding the battery failures.

I have long contended that a failure of the exterior-lights auto off feature was the cause of most of the dead batteries. And, I have long attributed this to leaving one of the doors or trunk open accidently. I have no doubt that the exterior lights will remain on and discharge the battery as you described if the drivers door switch fails in such a manner as to indicate that the door is always closed. The effect of this is canceled when there are passengers (I do remember that your passenger door switch is a problem too but that is a special situation) or the driver opens one of the other doors or the trunk. But, for the case where only the driver’s door is operated, and that switch is stuck in the closed position and the exterior lights are on when the ignition is turned off, the battery will certainly be discharged. It is a subtle sort of problem and my first concern after seeing your video was whether our advice to use the door lock button or the key fob lock (pressed twice, quickly) would guard against this sort of condition. The answer is NO. When you have a problem like this the car locks normally (locks and no audible warning) with the door pushbutton and it locks normally with the remote fob (locks and no audible warning). However, when you double-push the lock symbol on the remote fob the lights will not go off and that provides an indication that all is not well.

Your astute observations and keen videos have identified some other concerns for me.

The driver’s door switch is part of the technology that cancels the Hold feature, if it is enable, when the driver’s door is opened. And it is part of the technology that warns when the car is being left with the engine running. A failure like the one that you are experiencing will compromise some very important safety interlocks. I expect that if NHTSA becomes aware of this there will be a safety recall.

I knew you would see the light! (pun intended :) )

Intermittent problems are the most difficult to pinpoint as they don’t always present themselves when you want. This was an easy one as the intermittent switch failure was repeatable.

Looking at the service history of my car, about 4 months ago the previous owner had a road service call for dead battery. The dealer replaced the battery the same day. I suspect the door switch was the cause and possibly why they traded it in early.

Here is a simple video I just took. Ignore the yellow triangle on the dash as I had all windows and moon roof open for better visibility.

You can see that the first 2 times I opened the door there was no door open indication on the dash. The third time it finally sensed that the door was open.


JR

courtesy switch problems are quite common on the GS, and somewhat common on the LS460. and yes, they are the culprit of randomly dead batteries. they also cause the memory seat issues because after unlocking the car, many computers aren't woken up until the door is opened or the car is turned on. best way to diagnose it is push it over and over again and watch for the door ajar light to not come on right away or not come on at all. it can be intermittent though. just because it checks good at one time doesn't mean it's not causing problems.

Hey what happens to your switch when you let the door self close, or does it not do that with a stuck switch? Because I never slam my doors I'm wandering if slamming the doors cause the switch to malfunction.

I just checked. My door self closes fine even with the switch not sensing an open door.

Tomorrow the car gets both front door switches replaced by local dealer.

JR

anyone have the part number(s) for the door switch?

Anyone have the part numbers?

I believe mine is having this door switch issue as the lights sometimes do not turn off at all...