Drained Aux Battery..

lemon · July 7, 2009

So, I was doing the 'hold INFO button, turn parking lights on/off four times' thing last night to access some 'secret' menus. Foolishly left the parking lights on after accesing the menus. Then I was playing around with the NAV voice commands ("phone home" either turned the A/C on full blast, turned on the stereo or called E.T.). Finally tried saying, 'call home' and the system flickered a few times and everything shut down. Oddly, the hatch, which was open, began beeping continuously and the dash display showed 'shift to P to start' though the car was already in P. I wondered what the system mistook 'call home' for? Initiate self destruct?

I have a GEN4 8.1 disc in the drive (recently updated) and panicked, thinking the update screwed something up. Pulled the radio fuse and the negative cable, waited 10 mins, powered up and put the 5.1 disc in. YAY! I got the 'loading' screen and the green update bar. Halfway through the progress bar, everything shut down again.

Now, being used to normal cars, the last thing I thought of was that I'd drained the battery. Visions of the RX on a flatbed being towed to the dealership in the morning filled my head. Finally, when I couldn't eject the NAV disc and noticed that the dash lights had shut off, the lightbulb went off and I realized there was not enough power to run the Skynet computers in the car. Hooked up my digital charger - battery was at 22%, or just around 11 volts or so.

I had no idea how small a reserve that auxilliary battery has. Oh well, hopefully it will all power up when the battery is fully charged.

*edit* All charged up, loaded the 5.1 disc, then loaded the 8.1 disc. All in order. Also went for a drive with my Scangauge II hooked up, no error codes, and confirmed that the coolant was over 181 degrees before I did the ISC learning procedure.

Gryphon · July 8, 2009

It does not take much to discharge the aux battery, expecially since the system actually shuts the vehicle down long before the battery is completely dead, to protect the main drive batteries. One Lexus tech told me that the shutdown occurs at somewhere around 30% discharge.

Tom