NO power then full power - ???

Well my beautiful, 14-month old, problem free baby is not longer problem free.

Got in this morning, turned the key and zero - zip - nada. No Power. Nothing even lit up. No dash lights. No immobilizer light. No stereo or Ultra-Gauge. Nothing. It was like the battery was totally dead. I got a blip out of the starter .. like there was a little residual energy .. but that's it.

Pulled the key out, put it back in ... same thing. So frustrated and wondering how I was going to make my appointment, I sat there for a few seconds with the key in accessory position and all of a sudden, full power returned. Stereo turned on, immobilizer blinked, Ultra-Gauge turned on (and indicated I had a fully charged battery).

But the clock indicates that ALL power had been cut to the vehicle for some time, because it's off by hours, and all stereo controls are reset.

So WTF TW? What would make it seem like the battery was totally dead, and then all of a sudden on it's own accord restore full power?

 

I'm no mechanic but first thing I would check would be that the batter cables are connected tight to the battery posts. Other then that, I have no clue.

 

This and then check fuse boxes to make sure they are all tight. And plugs under the glove box and wires that go into the fuse box.

 

Well I mentioned the starter because I thought I heard something. I might not have. It was very quick. The bigger issue is it acted like the battery was totally dead. And then all of a sudden, just sitting there with the key in the ignition at ACC, all of a sudden full power restored and the Ultra-Gauge indicated a full battery.

• It definitely wasn't the immobilizer .. it was dead too.
• It definitely wasn't the ignition .. there was zero power to everything at all key positions.
• Battery cables are tight.

And it only happened once this morning (hadn't driven the truck for 36 hours if that helps). Been fine the next 5 starts.

I called the dealer, and they couldn't tell me a thing other than "bring it in and we'll try to recreate the problem". Of course, since the truck appeared totally without power for hours (again the clock is way off and the stereo reset) there are no trouble codes stored either. I have this feeling Toyota will have no idea what to do. So I reach out to the community.

 

Clean the battery terminals/cables.

sounds like a corrosion problem

 

Just dealt with the exact same symptom on my daughter's Camry. The battery cables and connections were nice and shiny. My volt meter showed 12.6 volts which is 90% charged. I grabbed the positive cable and it just lifted right off the battery post. I don't know why it worked itself off but I just loosened the clamp and put it on tight again. The car started and the charging voltage was 14.1. Perfect.

Why are battery post tapered up instead of down? Down would help prevent the cable from coming off.

 

After you have tried all of this stuff. Take it to the dealer.

 

UPDATE - I'm an idiot. I had checked under the hood and all seemed fine with the battery. Needed to check my cabin air filter, so I pulled the glovebox and passenger kick panel and checked all harnesses for tightness.

Opened the hood back up to check the fuse box, only this time I actually grabbed the negative battery cable and sure enough, as knayrb found with his daughter's Camry, it slipped right off. Turns out I had the truck in at the dealer, and they took the negative cable off and then only hand tightened the nut when they put it back on. But that was a month ago! Didn't cause a problem until today. Though the cable was seated, because it was such a loose connection, there must have been a thin veneer of corrosion forming.

 

Sounds about right. Had a similar problem with my Matrix about a year ago. Out of the blue leaving work one day, car wouldn't start. No turnover, no dash lights, no nothing. Battery cables were fine. Opened the fuse box and gave 'em all some good pressure...a couple of them seated themselves a bit when I did...car started right up, no problem since.

Normally, something like this out of nowhere is a loose something-or-other. Electrical components taking a shit tend to show spotty operation first (weak starts, flickering lights, low voltage, sensitivity to vibration, etc.) before going out.

 

vtek kicked it yo!