Total Power Loss...

Hi folks! I'm new to the forum (thanks for all of the welcomes BTW) and am in need of your expertise. I'll try to give you as much info as I can without writing a book. 2013 CM TRD SR5 5.7 Flex Fuel 4x4.
Thursday I drove to work, 7 miles, truck started and ran fine. 2 hours goes by and I need to run an errand, unlock truck with the fob, turn the key and NOTHING. When I say nothing, I mean nothing! No fuel pump relay 'click', no door chime, no immobilizer light, no door ajar light, no dome or cargo lights, nothing. Turned the headlight switch on...no lights at all. Stepped on the brake pedal...no brake lights. Hit the lock/unlock on the fob and the door panel...nothing. Totally dead. Thinking battery, I tried jumping it with a 7.3 F-350. Got a very dim door ajar light for a second, turned the key...nothing...and the door ajar light disappeared. Local Toyota dealer said battery so I decided to remove the stock battery and try an Optima redtop that I had at the shop but it was the wrong group size and I couldn't get the cables on the posts. Resigned to the fact that I was going to have to have it towed I reinstalled the stock battery. Tightened the clamps, closed the hood, opened the drivers door and WTF...I hear the door chime!? I have a door ajar light and an immobilizer light!? Turn the key and I have nav and tunes!? It fires up and runs fine. Started the truck several times in a row without any problems and it's been fine since then.
Friday morning, after sitting all night at 25 degrees I put my multimeter on the battery and got 12.42 volts, drove to work and metered it again and got 12.8 volts. Ran to the Toyota dealer at lunch and the tech put his scanner and load tester on it and said battery was fine.
Needless to say, I'm stumped. I've gone thru the fuses in both blocks, checked all the ground points, the clamps are clean and corrosion free, cables appear fine, battery tests fine, the truck hasn't been in for any kind of service where something could've gotten disconnected, it's hasn't been exposed to lots of water or snow. The service writer and the tech at the local Toyota dealer were perplexed as well.
Please offer you thoughts on this. With the wealth of knowledge here, I'm hoping someone can shed some light on what kind of voodoo inhabits my truck.

 

Sounds like you had a loose battery cable to me.

 

What blue said! Or you got gremlins! We've got a '99 Lexus that's got window gremlins.

 

^^^^+1.

 

Welcome. Loose battery cable

 

Thanks fellas. A loose cable seems a likely culprit and I don't remember if I checked the clamps prior to totally removing the battery. What stumps me is that if I did have a loose cable, jumping it off of the diesel and repositioning the jumper cables once or twice seems like it should have been enough to at least give me lights or a door chime.

 

I would remove both battery cables from the posts and use a wire brush to clean the cable ends and the battery posts. Do the same thing to the ground end that bolts to your fender. A corroded or otherwise contaminated battery cable could give you these exact symptoms, including the failure to jump start, as well as its magic resurrection.

 

I've been told that BMW puts (or did at one time put) a special coating on their terminals that made jumping them very difficult. One time my sisters battery died. My dad somehow figured out the jumper cables didn't have continuity in one of the leads. He touched the metal bumpers together and used the good lead and jumped my sister's car. For me it was/is his most impressive MacGyver ever.

 

Yeah, you'd think at least there would be something even with a loose cable. Maybe the computer needs to see full power before anything works. Sometimes if the battery is totally drained it needs to be charged for quite a while. I had a nearly new optima in my 1st gen, ran it dead in 20 minutes while having lunch one day. Whoops, the lights were on. Had a brand new Chevy jump it and it took 1/2 an hour of revving the Chevy before my truck would turn over. I'm not impressed with the optima. Won't be buying another. Got one in my cougar to, last year after not starting the car for a couple months(bat dissconnected) I had to charge it for two days before the car would crank over by itself. Had to charge it several more times and drive it to get the overpriced gimmick back to full power.

 

I'm not an Optima fan either but I had a new one at the shop and after jumping failed I figured I'd give it a try. The weird thing is that from the time I removed the stock battery, tried the Optima and reinstalled the stock battery only about 20 minutes had passed and the stock battery just sat on the bench while it was out of the truck. As soon as I reconnected the stock battery I was back to full power. ECU problem?? Maybe I'm over analyzing??

 

Warren, I hope someday I get to pull a full on MacGyver like your dad did. It doesn't get any cooler than that!

 

Update to my total power loss issue. Spoke with the guy who does the remote start installs at our shop and his thought was that the ECU "blipped" out. He likened it to a laptop or smartphone freezing up and needing to be turned off to reset and then turned back on, hence completely disconnecting the battery reset the ECU. Makes sense I guess and after 20+ years of messing with vehicle electronics I trust his diagnosis. Has anyone else ever run in to this?

 

I still think it was a loose battery connection. I don't think the ECU has anything to do with the dome light or the brake lights.

 

I'll ad my vote in for the loose cable. Had that happen on a 1992 Chevy K1500 Blazer. Couldn't figure out what was wrong until I moved the ground cable a little. It wasn't the connection to the battery, though. It was the ground lead connection to the chassis that had loosened somehow. Once I tightened that back up, all was right with the world! I doubt the ECU would prevent the dome lights from coming on, but I don't have a schematic in hand to verify that.

 

Thanks fellas for all of the suggestions. I'm still scratching my head. I've just now had the truck for 8 months and when I first brought it home there was a lot of corrosion on the battery. I soaked and brushed and picked until they were clean. I did however spray the posts with CRC corrosion preventer before I put the cables on. Once the cables were on I gave them another shot and I also used some felt washers to stop the battery from venting onto the posts and clamps. So, maybe that was it? I don't know. I checked all of the grounds on the fenders and the one under the airbox. I also dropped the skid pan and checked the main ground from the battery down to the block...all were clean and tight. Cable to and connections at the alternator looked good as well. I'm 99% sure the cables were tight, but there is that unknown 1%. So tomorrow I'll pull the cables and clean everything. I need to pull the battery anyway to drill a drain hole in the tray. There was some water in the tray and I'm way too OCD to leave it. Thanks again for the feedback and all of the suggestions, I very much appreciate it.

 

I agree with everyone else in that it is likely loose battery cables. However you mentioned that the voltage decreased after sitting at night. I am sure you have already checked all of this but I will mention it just in case. I would check all of the accessory lights and make sure that they are not on(with the bulb being burnt out). I had this issue on my 4runner, it took a while to figure out what was causing the battery to lose voltage. It was just a dash light that was on with the bulb burnt out. Also I had the battery deplete(after 2 weeks of no running), form a cell phone charger plugged into the 12 volt in the center console.

 

The voltage didn't decrease. I just let the truck sit overnight to see if it was decreasing. When I checked it the following morning it was at a solid12.42 volts. The only reason I'm discounting the loose cable scenario is that before removing the battery from the truck I tried jumping it with a Ford F-350 with dual batteries, so I know that truck was more than adequate to jump mine. In the process of jumping mine I removed and reclamped the jumper cables 2 or 3 times. That leads me to believe that at some point I should have wiggled a loose clamp enough to at least get dim headlights. Also jumper cables being clamped directly to the battery cable clamps should have put enough juice to my truck to get dim lights, a door chime, door ajar light, immobilizer light. I had absolutely nothing. It's as though there was no battery in the truck at all. I removed the battery completely from the truck, put it on my charger and the charger immediately read full charge. 15 minutes passed, I reinstalled the battery and everything worked perfectly. That is why I'm leaning towards a computer reset. ECU may not have been the correct term, BCM was what was in my head. The truck has been fine since, not one hiccup.

 

Had the same problem, took the battery cables off, for about 5 min. Reinstalled them and had power, truck fired right up

 

Just parked my truck tried to lock with fob and nothing happened. I got back into the truck and it was completely dead, no power at all. The battery cables are tight, there is zero corrosion, volts read 12.34. For months all the pilot lights come on and off at random, stay on sometimes too, and in different combinations. I suspect its the ECU.

 

Just went through a similar fiasco. After running just fine and parked for 2 days, no dome lights no nothing. The original 3 year old battery completely shot even though it shows 13.4 V. I did learn that the local Farmer's CO-OP knows more about load testing a battery than the Toyota dealer.

If you're a DIY'er and never replaced a battery in a tundra i may be able to save you a bushel of time and about a 55 gallon drum of frustration.