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Hyundai unpredictably shuts off while driving

I’ve got a 2003 Hyundai Elantra. I bought it new and, as i live in the city, i don’t drive much and it’s only got about 50,000 miles. while on a road trip two years ago, the car started gurgling while driving on a highway and then stalled. it started again, drove about a half hour, and then stalled again. it started up, we drove it to a repair shop that did some electrical work, drove it around for 60 miles, and couldn’t reproduce the problem. we drove it another three hours and it stalled again and wouldn’t start. it was towed to a repair shop, they did some electrical work and it worked fine for the rest of the week.

Months later, I went to turn on the car and the battery was dead (which had recently been replaced). I bought a new battery and the same thing happened a few months after that. A mechanic figured the security alarm (which we got post-market and was always funky) was draining the battery and disconnected it. the car was totally fine for another year and took us on several long road trips without issue. Last weekend, we took a weekend trip about a 100 miles away. We got to our destination perfectly fine, drove around for two nights perfectly fine, and on the third night the car stalled while in reverse. It started up immediately and drove fine after that.

Really not sure what to do here. The car should have a long life ahead of it, but i’ve already sunk a lot of money trying to find this problem which is almost certainly electrical but keeps foiling mechanics.

There’s a year between fixes.
This may not necessarily be the same problem as the mechanic fixed a year before.

When it dies, do the dash lights come on? Or do they die completely, like when you first get into the car?
If everything just dies, it could be related to the ignition switch – basically the car thinks you’re turning the ignition switch to off. There are many things that could cause this, obviously, but tell us what the dash lights do as that could be an indicator of something and we’ll go from there.

There was a recall on this a few years ago. Hyundai contracted out the fuel pumps and many of them failed on the road. Talk to the dealer

Thanks for the help.

The first time the car stalled while driving all the dash board lights came on - check engine, battery, etc… The next time, nothing, the car just shut off. The dashboard lights went out and the engine shut off. The last time it happened (two years later, this past weekend) the car just shut off. Dashboard lights went out and the engine shut off. I put the car into park and restarted it, and it worked fine after that.

I believe replacement of the ignition switch is one of the repairs performed by the first mechanic two years ago. I’ve had several diagnostics run since then, and nobody finds anything. I have a vacation planned for three weeks from now and I’m really unsure what to do.

If the lights go off completely, it is like turning the key off. There’s no interlock that could make that happen.
The ignition switch, when intermittent, can be a maddening problem.
Do you have a lot of keys on your keychain? Sometimes the lock can wear out prematurely if there’s two pounds of keys hanging from it.

Let me see if I can dig out the schematic to your car. Maybe it has a relay in between your ignition switch and the rest of the car…

Okay, after some digging, I found the ignition switch on your car.

I would trace the wires that have the ‘ON’ position in common. They seem to go to several fuses. Check those fuses first, making sure they are seated well as that could ruin your day.
A way to diagnose a problem like this is to instrument the problem: For instance, you could jury rig small lightbulbs behind those fuses and ground to see which bulb goes out when the car fails. That would be an indication as to whether the ignition switch is on its way out. Turning the switch off and back on likely cleans the contact or happens to cause it to make contact.
In lieu of that, you could just replace the ignition switch but I hate replacing something unless I have evidence that shows it is bad. After all, it could be a bad wire or connection too.

Also, when the car dies, does something that is run off the ACC position still run?
In other words, your radio likely does not turn on unless you have the key turned in ACC or ON. Does the radio die when your car dies? Knowing that can be an important clue.

In case you are electrically savvy, this site has a lot of service information regarding a fair number of modern cars and that’s where I found the schematic to your car.
To get in, enter barcode 02378001078755

Hi I have a 2012 Elantra limited and I’ve been having the same problem. The first time my engine stopped while driving the car only had 12,000 miles on it and I purchased the car brand new. (I have always brought my car to the Hyundai dealer for repairs). It has happened more than a dozen times and I am always told that “they cannot replicate the problem”. I have been going through this for five years the last time this happened I was 7 months pregnant. And now again with my 8 month old daughter in the car, I was 50 feet from the entrance to a major highway, it’s scary to think what would have happened had I been on the highway! Now I have a new ealership with my car and after explaining my situation and lack of answers from the original dealer have already said if the problem can’t be replicated I should drive an unsafe vehicle back to where I purchased the car 2.5 hours away and not to worry because I have roadside assistance!! I now believe that Hyundai is more than aware of these issues and just don’t want to be bothered. I have an open case with Hyundai USA and they have contacted the dealership and let them know they are to keep my car there until they have a repair, it is looking like an engineer is going to be sent to further troubleshoot. Did you have any luck with a repair?

Quote, supposedly from a Hyundai mechanic: “Hyundai has released many TSB’s regarding crank sensor [failures] on most of their vehicles.”

I would have them replace the crank sensor.

Sorry to hear about this, I know how scary it is when you lost faith in
your car on the road. I’m not exactly sure what we did that worked, but we
took the car to a number of mechanics and we haven’t had any issues with it
stalling while actually in use. One thing I know we did was have the car
alarm disabled because one of the mechanics told us it was draining the
battery. We also had a lot of the electrical wiring replaced as well as the
ignition switch. We also had a problem with the car not turning on, but we
got from these forums to put the car in neutral and then start it when that
happens, which seems to work. I’ll ask my wife if she remembers anything
else specific we did.

Have someone look at the battery cables and power and ground connections. You are loosing all power since the dash lights are out. It’s either the ignition switch or switch wiring. Bad battery cables/connections, especially grounds, could cause this.