Dangerous problem with my 24 Sportage PHEV… Anyone else?

My car had a big issue today. I have a 24 Sportage PHEV, less than 5k miles on it.

I went to start the car, and it made the usual EV start-up sound, but then all the lights came on, and a big ‘Check Brake System’ alert flashed across the dashboard in orange/red. The car then stopped responding, turned off, and the screen went black. I also heard noises like it was trying to engage the parking brake several times. After that, the car seemed completely dead. Nothing was responding, not even the remotes.

I’ve got a NICO battery jumper, and this was my first time using it on this car. I wasn’t sure how to handle the hybrid system. I found the positive contact inside the fuse box but struggled to get a good ground. 2 hours later, I found my voltmeter and read 5V at a point of contact.

I tried the jumper again, and this time, it detected the battery. Strangely, the car started itself with no one in the driver’s seat. The fan, engine, everything just switched on. If the car had been in gear, it could’ve driven off by itself… This is seriously concerning.

I drove it to the Kia dealership, but it was already late (4 PM), so I brought it back home and plan to return tomorrow morning. The car seems fine for now.

Also, I unplugged the dealership’s GPS tracker that’s connected to the ODIN just in case it was draining the battery. Anyone else had this happen?

If your 12V auxiliary battery is drained, Kia advises you to remove it and charge it slowly. Jump-starting a PHEV isn’t recommended because it can be dangerous. Please reach out to a professional to avoid any risks, whether to yourself or the car. Make sure to go through the owner’s manual for proper instructions.

@Alex
I’m hoping the person who posted this knew what they were doing when they found a positive jumping point in the fuse box, especially since they thought it could be the GPS unit draining it and removed it themselves. But 5V sounds extremely low. Normally, I’ve only seen 12V batteries show low in the high 10s or just completely dead at 0V. If it really was 5V, I wonder if they were jumping a low-voltage line, like one for a camera or antenna. Using a jump starter on the wrong line could cause damage.

@OptimaOwner
I used the vertical metal bar inside the fuse box, which had a red positive symbol on it, as shown in videos of similar cars. I also found it weird that it only read 5V.

What’s even more surprising is that when I connected the jumper and the NICO device detected the battery, the car just switched on by itself, with no one in the driver’s seat. I disconnected everything, turned the car off, and started it again before heading to the dealership, and it ran perfectly fine afterward.

@OptimaOwner
Sure, there are accessible places to jump the battery in the engine compartment, but Kia specifically advises against this method. Jump-starting the car might have worked, but it’s risky, especially when you’re not getting 12V readings. A low voltage like 5V suggests a connection issue, which could lead to serious damage or even a fire if handled improperly. It’s always best to get a proper diagnosis from a trained technician.

@Alex
I called the dealership, and they told me to call Kia roadside assistance and jump-start it, then bring it to the service center…

@OptimaOwner
I just tested the same contacts, and now it reads 11.4V.

@OptimaOwner
Yes, you can jump the vehicle. The battery post is in the engine bay by the fuse box and connects to the battery in the trunk. I had a similar issue with my Sportage. The ICCU (Integrated Charging Control Unit) wasn’t charging the battery correctly. I also saw 5V readings. The GPS might be the culprit as well.

@Alex
The owner’s manual actually has instructions on jump-starting with a portable 12V jumper or another car.

zack said:
@Alex
The owner’s manual actually has instructions on jump-starting with a portable 12V jumper or another car.

I double-checked the manual, and you’re right. It does say to check the battery first and then jump-start if needed. It talks about pressing the 12V reset button, but that’s for the HEV models only. The PHEV has a regular 12V battery in the rear cargo area, and it says you should remove it for charging. The instructions are a bit unclear, though, especially during an emergency.

@Alex
Yeah, and it’s hard to get to the cargo area when there’s no power… I found a thread on the Kia forum about a similar issue with the 2023 PHEV, and they ended up getting a battery replacement.

I don’t think you need to worry about the car starting in gear. It uses a shift-by-wire system, so there’s no direct connection between the shifter and the transmission. I’d guess the software would always default to putting the car in park as a safety feature.