2019 Kia Niro Fuel system Problems

My car is a 2019 KIA Niro Hybrid. It's only 7 years old, and my husband and I have been the only owners. It only has 61,000 miles on it, and it is serviced regularly and has to pass a state emissions test each year. As I was driving the other day, the dashboard lit up with critical alerts saying "check regenerative battery" and the braking system went completely soft; I could not stop the car using the brakes. It was terrifying. I had to pull off the road and use the emergency brake to stop the car. This was an awful incident that could have resulted in deaths or serious injuries. Again this is for a car that is well-maintained and well under 100,000 miles.

NHTSA ID

11745988

Incident

Jun 20, 2026

While traveling from upstate New York, the vehicle displayed an engine overheating warning shortly after startup while the engine was still cold. Because I was away from home, I stayed overnight and the next morning took the vehicle to a Kia dealership for inspection. The dealership inspected the vehicle and diagnosed a problem with the exhaust heat recovery system pipe. According to the service department, coolant is leaking internally through this component and is being burned in the exhaust system. The cooling system was pressure tested and held pressure externally, indicating the coolant loss is occurring internally through the exhaust heat recovery system rather than from an external leak. This condition can cause coolant loss and overheating while driving. If the engine overheats while the vehicle is in operation, it could create a safety risk due to sudden loss of power or engine damage. The dealership confirmed the diagnosis after inspection and testing and provided a repair estimate to replace the affected exhaust heat recovery system component. The overheating warning message was the first symptom observed prior to diagnosis. The problem was confirmed by the dealership after inspection and testing. This issue may indicate a defect in the exhaust heat recovery or thermal management system used in this hybrid vehicle, as coolant is entering the exhaust stream internally rather than leaking externally. If this type of failure occurs in other vehicles, it could lead to overheating while driving and potential engine damage.

NHTSA ID

11724340

Incident

Feb 8, 2026

12 volt starting battery (Lithium Ion Polymer) pn 37507-G2120. battery swollen and will not take charge (2.5 years old) 15,000 miles on vehicle. This battery powers dash and all related safety systems. Dealer refuses to look into problem as batteries are on national back order status and cannot fix due to parts availability. 3 dealerships have been contacted, all have been making excuses for other systems at fault to avoid recognizing battery is defective. I have been without use since Mar2021.

NHTSA ID

11462427

Incident

Mar 24, 2021

There is a pause upon acceleration from a stop (unresponsive). Then the vehicle will lunge forward and make a loud noise. For both driver and passengers, it can be quite startling and feels as though the car has been hit from behind. This started happening in the fall of 2021, when the car was about two years old with about 18,000 miles. It has happened about a dozen times in the six months since first noticed. It seems that this may be a software issue related to the hybrid system - a lag in triggering which motor to use for acceleration.

NHTSA ID

11459321

Incident

Nov 20, 2021

Starting battery (which operates the safety systems) was getting progressively worse until vehicle could not be started. Upon inspection it was determined that the 1.5 year old starting battery was swollen and defective. NOTE: Vehicle did sit for 12 months in estate litigation.

NHTSA ID

11453100

Incident

Feb 20, 2022

THE PROBLEM THAT I'M I'M HAVING IS A CODE P0456 (EVAPORATIVE EMISSION SYSTEM LEAK DETECTED, WHICH IS A SMALL LEAK. THE REASON WHY I'M WORRIED IS BECAUSE THE GAUGE FOR THE RPMS GOES ALL THE WAY ACROSS AS FAR AS IT CAN GO, IN OTHER WORDS IT'S LIKE AS IF I'M PUSHING DOWN ON THE GAS PEDAL AS FAR AS IT CAN GO , IT DOES THIS WHEN I'M DRIVING ON THE HIGHWAY, WHEN I'M ABOUT TO LEAVE A SIGNAL LIGHT FROM A COMPLETE STOP , WHEN I'M DRIVING UP A HILL IS WHEN IT'S WORST.

NHTSA ID

11255755

Incident

Aug 19, 2019

Mileage

5 mi

FIRST THE AIR CONDITIONER STOPPED WORKING FOR 2 DAYS. THEN ON THE 3RD DAY, 8/13/19, THE HEV LIGHT AND OIL LIGHTS WENT ON. THE ENGINE SLOWED DOWN. THE CAR WAS TOWED TO THE KIA DEALERSHIP IN ONTARIO, CA. INITIALLY THEY SAID IT MAY NOT BE COVERED BY WARRANTY. THEN ON 8/17 THEY TOLD ME THE AIR CONDITIONER NEEDS A NEW COMPRESSOR. THEN ON 8/23 I WAS TOLD THAT OIL AND METAL SHARDS HAD LEAKED INTO THE ENGINE AND THE ENTIRE ENGINE NEEDS TO BE REPLACED. IT IS UNKNOWN WHEN THE REPAIR WILL BE DONE.

NHTSA ID

11246151

Incident

Aug 13, 2019

Mileage

26,500 mi

AS I WAS DRIVING ON THE HIGHWAY, THE AC STOPPED WORKING. THERE WERE NO WARNING LIGHTS, ALARMS OR INDICATORS THAT SOMETHING WAS WRONG, BUT I IMMEDIATELY GOT OFF THE HIGHWAY BECAUSE I THOUGHT THIS IS NOT RIGHT. AS I BRAKED ON THE RAMP, THE CAR STILL WORKED, BUT WHEN I TRIED TO ACCELERATE LEAVING THE RAMP, THERE WAS NO POWER. I GOT INTO AN ADJACENT PARKING LOT AND TURNED OFF THE CAR. WHEN I TRIED TO TURN IT BACK ON, IT WAS COMPLETELY DEAD. I CALLED AAA, THEY GAVE IT A JUMP, BUT EVEN THOUGH THE BATTERY WAS FULL, WHEN PUT INTO DRIVE OR REVERSE IT WOULD DO NOTHING.

NHTSA ID

11245045

Incident

Aug 17, 2019

Mileage

6,140 mi