Had the common ICCU issue happen on my way home from work last week. The dealership is saying they don’t know what’s wrong, so I sent them some info from the ICCU recalls and NHSTA report. It’s a 2023 Limited with about 32k miles on it.
A lot of us seem to have this issue, so please don’t just complain here, but also make sure to submit your complaint to the NHSTA. Without this, they can’t gather real data on these problems.
This is especially important if you’ve already had all recalls or had the ICCU replaced before.
Dara said:
This is especially important if you’ve already had all recalls or had the ICCU replaced before.
Yup, I had all the recalls done.
Dara said:
This is especially important if you’ve already had all recalls or had the ICCU replaced before.
It’s not fully clear yet if OP’s ICCU failed, but just a heads up—ICCU failures can happen even if you did all the recalls. The recall checks if the ICCU is failing, but doesn’t stop future failures. A lot of people think they’re safe after recalls, only to have the ICCU fail later.
@Dane
They seem to be doing a software update, which might be to prevent more failures, though it’s not clear how much it helps.
Dara said:
@Dane
They seem to be doing a software update, which might be to prevent more failures, though it’s not clear how much it helps.
The software update was more about improving data logging, right? It doesn’t stop further failures.
@Ali
The update actually does help by preventing power surges that cause failures. We haven’t had any issues with ours after the update. It had the first update last fall and another recall update six months ago. We’re at 67k miles with no problems.
@Marley
Wasn’t some of it related to manufacturing defects, like coolant leaks into the ICCU?
Ali said:
@Marley
Wasn’t some of it related to manufacturing defects, like coolant leaks into the ICCU?
I think the coolant leaks were only an issue for 2021 models sold in Korea, which were fixed before the US models came out. The surge issue is the main reason for failures now, and the update aimed to reduce those surges.
Sorry this happened to you. I had the same issue after doing the recalls too. Hope it gets sorted soon.
In case it helps, here’s my timeline: https://www.reddit.com/r/Ioniq5/s/sJJy4JM7KJ
Oakley said:
Sorry this happened to you. I had the same issue after doing the recalls too. Hope it gets sorted soon.
In case it helps, here’s my timeline: https://www.reddit.com/r/Ioniq5/s/sJJy4JM7KJ
Thanks. I’m probably going to have to keep pushing the dealership about this. Mine doesn’t have a loaner car program, so if this takes too long, I might have to contact Hyundai directly.
@Dru
My 2023 has the same issue. The ICCU part is back-ordered for 4-6 weeks, but the dealership is providing me with a hire car, a BMW IX1, at no cost. This is in the UK.
What exactly was the issue?
Was it a ‘check system error,’ an AC charging issue, or a 12v system problem? I don’t get why the dealership said they didn’t know…
Tech should be able to diagnose the issue using the Hyundai GDS system and find the code to guide the repair.
@Miko
“Check Electric Vehicle System” warning while driving. The 12v battery completely died and wouldn’t hold a charge. The dealership said they didn’t know what was wrong, just that the car immediately drained the 12v after being jumped.
Seems like it’s ICCU-related since it can’t keep the 12v battery charged.
@Dru
When the 12v battery dies, the tech can charge or jump it, but if the GDS doesn’t pick up any codes, they’ll just release the car. Unfortunately, once a bad battery dies, it happens again. If it happens multiple times, they’ll likely replace the battery under warranty, though. In my opinion, you’re better off replacing the battery than spending hours at the dealership.
@Dru
I had the same issue, and it turned out I needed a new 12v battery. The message you’re seeing is the same one I got.
Eli said:
@Dru
I had the same issue, and it turned out I needed a new 12v battery. The message you’re seeing is the same one I got.
It took about a month and a half for the new EV battery to arrive.
@Dru
It could just be that the 12v battery isn’t holding a charge anymore. They should replace the battery and see if that fixes it. If not, they can test the old one for a warranty claim.
Dane said:
@Dru
It could just be that the 12v battery isn’t holding a charge anymore. They should replace the battery and see if that fixes it. If not, they can test the old one for a warranty claim.
Maybe, but you’d think they could check the 12v battery quickly as the first step ¯_(ツ)_/¯
@Dru
If the car completely died, it’s best to replace the 12v battery with a new AGM one. You can even buy an OBD device and monitor the battery’s state yourself. But if you’re worried, a new battery might be the better choice, as the old one will likely die again.