everything shuts off while driving
 

I have an 01 Sonata v6. While driving under normal conditions the car has been just shutting off. Has happened 2x - 1x on a surface street going 25-30 mph and today on the freeway at 65 mph. The engine stops, the radio turns off, the lights turn off and there is a clicking from the dash area. Then it turns right back on. It "flickers" for lack of a better term. The first time I pulled over and checked the battery connection and it was loose so I figured that was the problem, but this time the battery connection felt tight. Please help!

I'd suspect the cables are still loose or bad. Has the battery been touched recently?

It sounds like the ignition module is going bad. The lock drum where you insert the ignition key makes an electrical contact to signal the ECU that the key is inserted and the engine can start. When this ignition module goes bad, the contact is intermittenly broken and the ECU thinks there is no key... effectively the same as you basically taking the key out of the ignition while in motion which, by the way, you can't do because of the safety features.

Needless to say, it's a very dangerous situation because you will have total loss of control of the vehicle. Take it in immediately and have the dealership or service shop take a look. I would bet my lunch money that it's the ignition module.

When the engine is running, there is really no need for the battery. The alternator produces enough electricity to keep everything running.

If the car fails to start, then I may suspect the battery. If the vehicle starts then loses power and refuses to start, then I may suspect the alternator, the battery or both. In other words, if the alternator is bad and is not recharging the battery, then the car has to use the reserve power in the battery which will be drained. At that point, the car should not start again. But the OP said the car starts back up.

Thus I would rule out the battery. Maybe the ground wire, but not the battery or the alternator based on the description.

^^ I would bet my lunch money it's not.

Oh really? Go read this thread and come back: https://www.hyundaiforum.com/forum/s...ead.php?t=9072
I'm not saying this is the problem, I'm just saying check here first. Many times it's the simplest things, not the most complicated. Check the simple first.

Update: Installed new battery connectors and that didn't fix it. Took it to a different mechanic who said it was the battery. Forgive my lack of specific technical terms, but my understanding is that inside the battery there are separate "cells" and one was loose and would lean over and touch the cell next to it -- and that caused the short. Got a new battery about a month ago and I haven't had a problem since. Thanks to everyone for their quick replies! :):)

So, where's my lunch?

I think it got shorted inside that battery. :D