That must have been really scary. Thankfully I've not had that happen. Wish I could help, but I'd visit the dealer for sure. Good luck.

Geoff

 

I’ve not had that happen, but my cruise control regularly just decides to shut itself off randomly when out cruising on the highway. Very irritating. Nobody has a fix.

 

Did you take it in to be checked?

 

How fast were you going? Did you happen to notice the battery charge level?

Easy to picture a possible explanation, particularly with the same driver experience with two different small economy hybrids. High sustained speeds required motor support draining the battery until speed could no longer be maintained.

 

Wouldn't the system default to gas engine ?

 

We were going 80 which is Utah highway speed. They need to make these cars a bit more hearty, if that’s the case.

 

If you need to maintain 80 mph going uphill, you need a more powerful car. Try putting the transmission into Sport mode and see what happens. Your gas mileage will take a hit.

 

Probably off base , but since it happened to two cars, could it be the gas you you are using. Do you use the same gas station every time...

 

It seems ridiculous to think that a Niro engine won't be powerful enough to maintain 80 mph with a depleted drive battery. I think this can't possibly be correct.

 

This happened to me on the freeway about a year ago! I was going about 80 in the fast lane, suddenly no power. I too had to pull over to the side, shut off the car and then restarted the car. Did not have a problem after that. No one has answer. I have a 2023 Kia Niro Hev. I use 89 gas in my car from Costco.

 

Water in gas ?

 

I doubt it was a gas problem.
The constant in these cases is the high speed and probable altitude change and the ICE simply cannot handle that with just slightly over 100hp.
The electric motor is needed to assist and if it has been drained, the computer is going to make you slow down and possibly even pull over to start charging that battery or at the very least, allow the ICE to handle the requirements.

 

It seems some want the economy of an "econobox", and the performance of a sports sedan. Before hybrids, if you wanted economy, you bought something like the Geo Metro XFI we once owned. It did regularly get 45+ MPG and often did better than 50. But performance? No idea about top speed, but with 1 adult and 2 teenagers in the car, it could only manage 45 mph on a long uphill on an expressway in 4th gear and full throttle. We got passed by semi's.

When the hybrid battery is depleted, the power to weight ratio of a Niro isn't much better than the old Geo.

 

I once saw 83 merging onto the interstate. It seemed to get up there quick enough, and was not too noisy. Normally I max out at about 72 when the speed limit is 70.

Geoff

 

You might well be able to reach 100 mph in a Niro HEV. But that is irrelevant to a discussion of a sustainable speed. Typically a speed limit on a freeway is the base speed, or at best an average speed. So the OP may have had his issues at closer to a sustained 90 mph.

I suspect absent hills, the far more aero Hyundai Ioniq HEV with the identical drivetrain can readily maintain 80 mph making it a more suitable choice owners that need to drive that fast and need an entry level price and can live without the crossover shape (and seat height). About 10% better mpg as well, and likely more like 15+ at 80 mph compared with the Niro.

On long upgrades, even the Ioniq is eventually speed limited, at least that is what I read in the Ioniq forums.

 

Hey do you happen to know which dealership you took this car into? Have you gotten any resolution? I am having the exact same problem with my 2023 Kia Niro and I am scared to drive it. I am talking with the Kia service at corporate but they do not have any record of the issue ever being a problem for others.

 

Hey everyone.! I have a 2024 Kia Niro , it went completely dead on the road . No lights no nothing, checked every scenero, had to get towed to local dealer, luckily was able to get to shoulder but not completely, no emergency lights or anything. Has anyone have any idea?
Local dealer has NEVER heard of this, can’t seem to find any reason or information. Any ideas please share, oh all the oil changes, and service done by dealer ship,
Thank you in advance

UPDATE!!!!
They say we were running 80% water, 20% fuel. How in the **** does a HEV run over 200 miles the previous day and all of a sudden this happens. Same gas ⛽ n truck daily driver no issues.
No vehicle can run on 80% water, and why did water in tank drain both batteries? Makes no sense. Why wouldn’t a mechanic start with the basic checks then all of sudden oh let’s check fluids!!
They are saying our gas and water no WARRANTY! After two weeks.

 

Traded in my 2016 Kia optima hybrid because it would suddenly lose power on freeway. We would get a ‘warning hybrid system failure’ light on dash. But despite multiple dealership visits and even taking a picture of the dash warning, they could never figure it out. So, for that reason, we traded that car in for a new 2023 Kia niro and it’s doing the same thing! No dash warning though. Typically it happens while going freeway speed, and then it suddenly losses power and the gas pedal makes zero difference. For a while we thought maybe it was a glitch from cruise control perhaps switching off. Today, I nearly got hit by two semi’s when I lost power in the passing lane but was able to pull over, shut off engine, then restarted and continued on trip (but stayed in the slow lane). Of course, it’s a weekend, so appreciate any thoughts!
Cindi

When I had mine, the 'dealer (where I bought it)' replace the transmission under warranty... ran fine after that... first dealer replaced a module... did not fix it...

 

The very same thing happened to me in my 2023 Kia Niro but at slow speed, trying to accelerate from stop or going up an incline. Car totally lost power. Took it in to dealer. They have had it for two weeks and are "consulting their tech person." What the heck! I am trading it in, reluctantly because of the cost, for a 2025 Kia Niro. Hope I am not making a big mistake. Love to hear about the experience of others with this. I have contacted a lemon law lawyer about it. I think it is a life-threatening issue that Kia absolutely needs to address yesterday!

 

Never had this happen, but I'm interested in what the dealer finds as the cause. Maybe you're not waiting for a solution. Can't say I blame you.

Geoff

 

For me it was about 2 days.... but then that was 10 or so years ago...
and it was my only vehicle... so it's not like I could just take it in and drive something else.. 8)

Could be different now... 8)

 

Did you get this resolved? My husband is having the same issue with his Kia Niro 2019 Plug in hybrid when it switches from electric to gas

 

This thread is about the second generation Niro, 2023 and newer. It there’s no thread about this in the first generation section, please create a thread in the problems and issues section. 😊

 

there seems to be a pattern with loose ground wires doing a number of different things. i had to deal with a stalling issue for a few months and a loose ground wire was the issue after multiple dealership visits and tows.

the service advisor when he fixed mine told me that they had another ground wire issue which would not let the car "turn over" but had infotainment and dash controls.

def would be something to have them look over, especially if they techs are struggling to come up with a solution.

 

loose ground wires doing a number of different things.

The terminology is electrically inaccurate. This is the negative circuit wire. We know that both wires of a circuit, positive and negative for a DC circuit, must be connected clean, dry, and tight. There is no actual ground; nothing connects to the earth like your home wiring does. A car's "ground" does bond the negative to the chassis, but that's still not an actual ground.

So, it is easy to understand why a loose ground wire messes up many things. It is a loose negative circuit wire, and things can't work with that.

 

For what its worth...I had a problem with my Ford Fiesta where it would drop out of cruise in the middle of driving. Turned out it was an improperly crimped lug at the end of a wire. It raised a check engine light but no codes when I got to the dealer. The 2nd time it happened I had them check the codes with the engine still running. Then the found it. Wire harness issues are very difficult to diagnose. Try doing it on a remote radar site on the north slope of Alaska/Canada.

 

@ alisa.strathearn (with apologies to atc 98092).
FWI my 2019 Niro PHEV dash lit up at about the 500 mile mark. At 1st it wouldn't start after I pull over, but after a short wait it was drivable. Final analysis was "bad ground".

 

Traded in my 2016 Kia optima hybrid because it would suddenly lose power on freeway. We would get a ‘warning hybrid system failure’ light on dash. But despite multiple dealership visits and even taking a picture of the dash warning, they could never figure it out. So, for that reason, we traded that car in for a new 2023 Kia niro and it’s doing the same thing! No dash warning though. Typically it happens while going freeway speed, and then it suddenly losses power and the gas pedal makes zero difference. For a while we thought maybe it was a glitch from cruise control perhaps switching off. Today, I nearly got hit by two semi’s when I lost power in the passing lane but was able to pull over, shut off engine, then restarted and continued on trip (but stayed in the slow lane). Of course, it’s a weekend, so appreciate any thoughts!
Cindi

I had a similar problem with a Ford Fiesta. Didn't find any error codes. What I did was take it in when it happened and didn't turn off the car. They then were able to catch the code. It was a connector what wasn't crimped properly so the wire would come loose intermittently. Didn't loose power totally but dropped out of cruise. Hopefully they can case it down, I know its scary.