chuck58

The car is a 2000 LS-400. It has the NAV package. It’s been mostly garage kept, and trouble free, since I first acquired it 3 years ago. 88,000 miles.

I accidentally left the key in the ACC position overnight and completely drained the car battery. The car was in the garage, and the battery was completely discharged, such that absolutely no electrical equipment worked. NONE. I had to mechanically depress the gear shift lock switch, allowing me to get the gear shift into neutral, in order to push the car out of the garage and subsequently attempt a jumpstart. I performed a jumpstart in the morning, and during the jump start sequence, it did turn over, strong. During the start sequence, the security alarm was going off and the horn was beeping continuously. I replaced the battery with a new one, closed the hood, and the initial start up was successful. However, I also incurred multiple electrical failures. The following electrical systems (at least these) never did power up, after the new battery was installed....

>accelerator pedal is INOP/non responsive. I have engine idle rpm only

>tilt and telescope INOP

>brake lights INOP

>tail light position lights (night running lights in tail lamps) INOP

> headlights work, but only on low beam. I cannot select hi beam with the light switch lever

>every interior light is INOP, including all dash lights, dome lights, radio and climate control lighting on NAV screen are ~ ALL ~ INOP

>ignition key will not lock nor unlock doors nor trunk remotely

>gear selector is electrically locked/disabled and INOP

And this is just what I’ve found. Probably some other things are rendered inoperative as well, but I simply have not found them. Any and all advice is greatly appreciated.

Chucky

Yamae

It is the often case that computers are not going into the power off reset sequence mode when battery is draining slowly because those computers are reset detecting the quick voltage drop. In your case, the voltage has dropped very slowly and computers were not able to terminate closing jobs since there came no power off reset signal. The circuit that makes power off reset signal needs the quick voltage drop. Too slow drop doesn't help it. As long as the jump start was not doing any harm, all you need now is to reset computers removing the battery's negative cable for 10 minutes and reconnect it. If it doesn't work, try again a few more times.

I also need to add, modern cars are not fond of jump starting due to the big surge spike generated when the starter stops. It often damages electronics circuits, you know? I hope your jump starting was not causing any problem.

chuck58

Thank you Yamae. I’m applying this corrective measure right now. I will leave the battery disconnected for 20 minutes or so and get back to you before I go to bed tonight. As you indicated, I may have to try a couple of times tomorrow as well (with a interval of rest for the battery and computers to reset). I sincerely appreciate your insight and expertise in this matter.
Chucky

chuck58

As described above, I have attempted reset of onboard computers 5 to 6 times, with 20-30 minute rest intervals. I will continue to attempt to this reset procedure a dozen more times if I need to.

Any other suggestions from those who’ve experienced this type issue? Many thanks.
Chucky

Yamae

Did you try it while the engine key is inserted and computers are working? The power off reset needs to be done while computers are ON. So your engine key should be at ON/RUN position when the negative cable is removed.

chuck58

Thank you Yamae, I did not do it in the fashion you just described. I was turning the engine off, removing the key, disconnecting the negative battery terminal, waiting 20 minutes, returning for the car, getting in the vehicle, closing the door, inserting the key and starting the motor.

I have a new understanding of how the procedure works, I will try that now. I’m not nearly ready to give up on this. Thank you again for your very helpful instruction. I will let you know how this goes.

chuck58

So, key should be in the ON/RUN position when I disconnect the battery terminal?
Does that mean the key should also be in the ON/RUN position when I reconnect the negative battery terminal?

So let me describe the correct procedure, as I understand it.

>approach the parked car in the following condition:
>the car is in PARK, key is OFF, and out of the ignition,
>the battery negative ground lead wire is disconnected from the battery,
>Get into the car, close the door, insert the key and turn the key to the on/run position (NOT start)
> get out of the car, connect the negative battery lead wire from the battery NEG terminal, and then walk away from the car for 20 minutes.

———— ———— ————— ————

>After having left the car sit for 20 minutes in the above condition, return to the car CONNECT the negative battery terminal lead wire to the NEG battery terminal.

Repeat as often as required.

Did I miss anything?

I guess you can tell, I road in the short bus on school days.

Yamae

Have you done the disconnection while the car is ready to start?

Try as follows.
Your new battery is connected and the hood is closed.
Lock and then unlock doors.
Sit in the seat and check following conditions:
the car is in PARK, key is OFF, and out of the ignition.
Insert the key and twist two clicks (To set it ON/RUN but don't start the engine.
Wait 20 seconds until the VSC OFF is distinguished then keep the engine key at the ON/RUN position.
Open the hood and disconnect the battery (only negative side is enough)
Wait 10 minutes and connect the battery.
Insert the key and twist two clicks.
Wait again 20 seconds until the VSC OFF is distinguished.
Start the engine.

If above method is not effective, it probably means 2 things.
#1 is the waiting time 10 minutes is not enough to erase stray electrons in chips.
--> in this case, you need to wait more time such as a day or so.
#2 is the side effect of the jump starting.

chuck58

Thanks Yamae. This is easy-to-follow instructions. When I get to the end of this, I will be sure to follow up, and let you know the outcome.

As a side note, I am starting to hear some electrical activity under the hood after having tried this new procedure. That is a positive change I feel hopefully one or two more attempts at this cleared up. Again, I will let you know the outcome.

chuck58

if I get to the end of step number one above, do I leave the battery disconnected and the key out of the ignition and the gear selector in park? Or is there some other condition that I should set prior to leaving the car for a long period of time? Other than that, everything else is understood clearly.

Yamae

You can't remove the key while the battery is disconnected. Also you can't lock the key by the commander without the battery. If you have to park the car outside and don't want the key left in the cylinder for a day or so, after the reset, connect the battery again and after removing the key and lock doors and then again disconnect the battery and wait 1 day.

timmy0tool

iTrader: (7)

i learned something new in this thread.
you have our resident LS400/Celsior electronics expert who resides in japan helping so i don't doubt you will have your car up and running in no time!

Yamae

As I read your first post carefully again, I realized that some of INOP items were not related to computers. For an example, brake lights should be ON simply pressing the brake pedal only. There's no computers to turn them ON. I worry that you did something wrong when you were trying the jump starting. I bet some of fuses are blown. Didn't you reverse the power cable?

Obctkillz

I removed and re-capped my ECU per tutorial on this website. Now, when I shut the car off, there is a buzzing coming from the IAC motor when the car is off that is draining the battery. Any thoughts?

chuck58

Yamae diagnosed this correctly. The problem is that the main alternator 120 amp fuse was blown. It’s wired in series and everything down line from that fuse was simply unpowered. The fuse did what it was designed to do, and protected the rest of the electrical system. I feel certain the damage was done while attempting the conventional jump start, using a donor car and jumper cables. Simple fix ~ not so easy to diagnose, at least for me. Thanks again, Yamae. You are a great asset to this website.