2013 5.7 CrewMax Shuts Off While Driving

Very recent issue...

2013 Tundra CrewMax, 5.7, AT, OTT tune, 85k miles, single owner

Drove it today after it sitting for a few days (normal) and went about 10 miles to the dump. I leave the dump and heading out from the stop light, I'm on the accelerator as normal and the truck completely shuts off. Dash off, engine off, no further acceleration. Then half a second later everything turns on again. Then another second later everything off again. I noticed that the battery guage is fluctuating from 14 to about 16 volts, back and forth. I go another 1/2 mile and boom, same thing. Everything off, and then everything on again. I let off the accelerator and coast for a moment (battery guage still fluctuating). I go another 1/2 mile or so, ease into the throttle, and everything is fine.

I finish the drive home, truck accelerates like normal. No issues. Anyone have an idea of what to look for? I'd imagine a short somewhere, but not sure where to even start. I just put a brand new battery in the other day. I've checked all those connections and they look fine. Ground is proper, no frayed wires.

I have a 1300 mile drive coming up on Friday and would love for it to go off without a hitch (as it it has the last 6-7 times)

 

Might want to get that new battery tested to ensure it is good. If that checks out check the alternator. Had same symptoms in an old vehicle turned out alternator went bad. GL.

 

I had them run the test at Autozone when I got the new battery because I was wondering about the alternator. Per the tester at Autozone, battery, alternator, and starter are good.

 

Check the battery connections, I'd even pull them and hit them with a wire wheel. Could also be alternator as said above since the voltage shouldn't be up at the 16V range. Also check any other ground connections around the engine bay (not sure where those might be). I've had similar issues on other vehicles from bad continuity at the battery or bad ground connections from the engine harness, and if you changed the battery recently that would be the first place I'd look since the terminals might not be making a good connection. I had a battery terminal on my buggy that couldn't crank the engine even though it was brand new until I hit it with some Scotch Brite.

 

So checked the connections. I have connectors where there is a wingnut on top. It's never been an issue previously, but remembered I recently wired up a new light bar. I'm wondering if the connections just weren't secure enough and it's jiggling around. The wing nuts for both the positive AND negative terminals weren't so loose that they would fall off, but there was enough that I could definitely spin them around a full turn. I'm going to hope that's was the issue and that we're all good now. I'll follow up on the outcome.

 

Checking battery connections is a good call.

Also, how many keys, knives, mace bottles, hand grenades, defibrillators, moon rocks, rabbits feet, and leprechaun heads do you have hanging off of your keychain? Too much stuff on your key ring can wear out the key switch and cause the vehicle to behave as you described. GM had a big problem with this in the early 2000’s which was exacerbated by people carrying 100 lbs of junk on their key rings.

 

16v????

First thing I am doing is putting a multimeter across the battery while the truck is running. 16v is to high… make sure you are in the 14v range.

Voltage regulator in the alternator could be on the way out.

 

Found this on TS... Voltage gauge jumping | Toyota Tundra Discussion Forum (tundratalk.net)

Certainly going to keep an eye on the alternator though.

 

I've always been mindful of this. Right now it's the Tundra key, the key fob, and two small kwikset house keys, and it's been like that for the life of the vehicle. I would be very surprised if the key switch was worn out by this, but I suppose anything is possible!

 

As said before, start with the simple stuff first like a bad ground. Just be sure to check all of them