Turning off dead car brings it back to life

[xpresschick]

I really hope someone can help because this is driving me absolutely nuts. my Elantra is 2017 and it's been acting real weird. I'll be driving or idling, and suddenly bam...the engine just dies without sputter or warning lights. And now drum rolls for the craziest part....? if I turn the car completely off, wait a couple seconds, and then start it again... it fires right back up like nothing happened and its nothing that a scanner is catching. It's happened a few times now, and every time I think I've figured out a pattern, it does something different. I'm trying to explain this as clearly as I can because it's so inconsistent and hard to replicate for a mechanic and I've used up all my independent girl power

I'm seriously at a loss here and kinda stressing every time I drive it

 

[FiftyAndFabulous]

@xpresschick it dies suddenly and then instantly restarts without a code huh? sounds like a classic sign of something momentarily losing signal or power.
have you check the sensors & relays, even without a code, the crankshaft position sensor is a prime suspect for this exact behavior. Also, the fuel pump relay is another common one. They can fail intermittently and not necessarily throw a hard code.
or do the wiggle test, while running, try gently wiggling wiring harnesses, especially around the engine, ECU, and fuse box. Sometimes a loose connection will reveal itself

 

[elantra_guy_12]

I really hope someone can help because this is driving me absolutely nuts. my Elantra is 2017 and it's been acting real weird. I'll be driving or idling, and suddenly bam...the engine just dies without sputter or warning lights. And now drum rolls for the craziest part....? if I turn the car completely off, wait a couple seconds, and then start it again... it fires right back up like nothing happened and its nothing that a scanner is catching. It's happened a few times now, and every time I think I've figured out a pattern, it does something different. I'm trying to explain this as clearly as I can because it's so inconsistent and hard to replicate for a mechanic and I've used up all my independent girl power

I'm seriously at a loss here and kinda stressing every time I drive it

Similar to what @FiftyAndFabulous said, I'd look into issues related to the crankshaft position sensor or the main relay!
The brief period you turned your car off might be enough for them to reset but the problem really remains.

 

[ElantraXpress]

You both did a great job identifying solid leads, when there's intermittent stalling without any codes, it usually points to a crank sensor or relay issue in my experience too. I really like the idea of the wiggle test, it's straightforward but can often be quite effective. @xpresschick, have you noticed if this stalling occurs more often when the engine is hot, or is it totally random? That could help us narrow it down further.

 

[Loseconnector]

Weird situation and some good advice here. I would also suspect the ignition especially if the one with a key, which I think is on the lower trim levels. What I would do here is get an obd scanner, one of those bluettoth ones and connect it to an app on your phone. Let it run and collect data. At the moment when the engine dies you should see some values going down and they can point you int he right direction.

 

[smartthrottlecrew1022]

Using an intelligent troubleshooting strategy with OBD scanner data logging can really help. By monitoring in real time when the engine stalls, you can clearly identify if the problem is related to ignition, fuel, or sensors.