It's Sunday - all repair options are closed and I'm dead in the water for work if I can't figure this out.

I got in the car to start it and everything looked dead. After everything appearing out (no lights in the cabin/dash) and trying it a few times, once (this is the weird part) it gave me the "no key detected" (I had the key of course) and I saw the ignition button light flash red. I needed to be somewhere and replaced my fob battery while out (I knew that was a longshot). When I came back, I tried again and never got anything. My lights were on the parking light postilion (I must not have twisted all the way), and I hadn't driven the car the previous day, so maybe that drained the battery (though I would have thought I would have noticed the lights were on, as I went through the garage a few times). Wipers were not off either, but that likely doesn't matter.

So I tried to jump it with a Sequoia (12 V in the trunk - used my physical key to open the trunk for the first time). Nothing. As in no electrical activity at all. Repeated process with a jumper unit. Again, I never got any sign of power at all. My gut feeling is that it's a fuse/relay, or some truly terrible electrical problem that will cost many bucks, and I'll have to tow it somewhere and let someone figure it out. BUT maybe someone here could tell me what replaceable fuse (that I can get at a pep boys) might be worth trying. It would have to be one that knocked everything out.

Worth a shot. Thanks in advance for any advice.

 

I believe its called a fusible link and probably located next to the batteries fuse box.

Have you tried pushing the start button with the key fob?

 

Yeah, I held the fob to the button.

I think I know the problem, though - I probably drained the battery entirely and I blew the fusable link (which is on the lead itself, over the battery) when I tried to jump it (like a moron I went black to post instead of grounding on the engine), Took the part out and ohmed it out, and it appears to be blown. Good news is should be a lot cheaper. Bad news I can't deal with it until Lexus is open, and hope they don't have to order it.

Thanks for the help, I;ll let you know if that works, but I'm too chicken to jump bypassing the fuse.

 

Ya def dont bypass it, you may fry the ecu. Glad you figured it out and should be easy to fix. On a positive note, thats better then towing it to the dealer and paying diagnostics fee

 

So this sounds like the 12v trunk battery didnt have enough juice to run the electronics. What if the 12v battery had enough juice to run the electronics but the traction battery was totally discharged or failed, how would we jump start the engine?? Since the traction battery turns the statrer for the engine.