Sounds to me like one or more cells are starting to have too high resistance which equals heat. I'd check by making sure the battery fan is working properly but would start budgeting for a battery pack soon.

 

Try getting a scanner that has hybrid vehicle profile and record all data from hybrid battery, then check if any cell has abnormal voltage or the temperature sensor gives correct reading.

 

You have any suggestions for a scanner? I have a 2017 Hybrid Lomited, now with 102,000 miles, have had numerous problems. so far any one that the dealer fixed under warranty, the battery controller was making the hybrid battery get so hot you couldn't touch it. That was in 2017 or 18. We get 40MPG, when new was upwards of 5o, so it has decreased some.

 

Are you the original owner? You should have lifetime warranty on the battery or if not then 100K miles. Rarely is anything "obvious" ever found by the dealer. Make sure you get a picture of something of that message to document it.

 

Yes, I'm the original owner. And I seem to remember when I bought the car that the warranty on the battery was longer than the rest of the car - but I don't recall the specifics.
And yes, I have a pic of the error message.
Thanks!

 

Funny enough, the same started happening to me - EV only range severely reduced from initial 25+ miles to something in the neighborhood of 15-17 miles after just 5 years and 70k miles and now the same “High System Temperature” message starting to show up more frequently, same as described by initial post. I had it in with the dealer about 2 months ago who kept it for several days running various tests and going back-and-forth with Hyundai engineering. However, they came back with 19 miles of official EV only range but said that no issues were found (not too surprised). Not exactly sure what they checked in detail but have a case number I can refer to in the future. Will see how things go and degrade and then try again to go for 100k/10yr hybrid system warranty and lifetime battery. Hyundai dealership was very accommodating though, not charging me anything for the extensive diagnostics (despite warning me initially about a min. $140 for that) and even providing a courtesy vehicle free of charge for 2 days. So I’m not too sour yet but probably will be in the long run if this issue is not being addressed satisfactorily.

 

My case is still not 100% resolved, but they've ordered a new battery and I will be getting a loaner car on Monday.
Initially, they found a faulty fan, but the problem didn't change when they replaced it so they ran some more diagnostics and they had to do some back-and-forth with some other group (I'm guessing Hyundai engineering) before they decided to order a new battery.
No idea how long it will take to get the battery - but they've warned me it could take a while (thus the loaner).
I'm willing to wait if it means I get this fixed "for good". And I will report back here when I know more...

 

It seems from various other threads and posts that replacement batteries are taking a very long time (ridiculous amount really - many months).

 

 

Hi,
I am also having the exact same problem. I just got the car back and they told me it was the water pump, but as soon as I drove it about 15 minutes the High Temp Sys switching to hybrid came on. Mileage is affected as well. I told them to check the battery but each time, they tell me all is well (even got the 700 dollar 60,000 mile plugin hybrid service). Did anyone every get this issue resolved? I really appreciate it.

 

Did anyone every get this issue resolved? I really appreciate it.

My car is still in the shop waiting for a battery and I've been driving a loaner for around a month now. I've heard nothing specific and been given no deadline, but the good news is that they seem committed to replacing the battery pack. (Or at least it appears that way).

 

Well, I am back at the dealership and a bit upset. I have brought my car in at least three times over the last three months concerning this issue. They might have to charge me a diagnosis fee. Nope, I told them this has been going on for three years with no resolution. I explained that others are also having the same problem and mentioned this forum. I wonder how much the mechanics are trained on the plugins or if it is just a do not want to fix the problem as they will lose money. Has anyone thought about submitting to the NHTSA?

Report a Safety Problem | NHTSA

shelley

 

Well, I am back at the dealership and a bit upset. I have brought my car in at least three times over the last three months concerning this issue. They might have to charge me a diagnosis fee. Nope, I told them this has been going on for three years with no resolution. I explained that others are also having the same problem and mentioned this forum. I wonder how much the mechanics are trained on the plugins or if it is just a do not want to fix the problem as they will lose money. Has anyone thought about submitting to the NHTSA?

Report a Safety Problem | NHTSA

shelley

Hi, I have a 2016 PHEV and started getting the same message a few weeks ago and the car has not been in high heat conditions. I’m the orig owner and the hybrid battery and transmission was replaced 2 yrs after I bought the car due to a hybrid system failure issue. It took the dealer a few months to figure it out and over a month to replace the battery since it had to be shipped from Korea. I also took it in last year for an intermittent charging related issue. They gave me a loaner for a week but could not figure it out. I still have the issue and my EV range has declined to 20 mi. There are only a few mechanics that are trained on plug in hybrids, so make sure you ask for one that has worked on dealing with PHEV battery issues. Unfortunately based upon these posts, I suspect the battery will need to be replaced again. Fortunately I have not been charged for anything to date since the battery has a 10yr/100k warranty, but it’s a hassle. Given the supply chain issues with batteries, I would not be surprised if it takes at least several months to replace it. I’m planning to take it in next week. I’ll post an update after they figure out the issue.

 

I appreciate your response. Over the past few months, they have replaced my water pump and then a second pump (guess there are two). STill no fix and mileage is down. It is so frustrating to go every few weeks to the dealership (I also bought it new from this dealership). In my opinion, it has to be a manufacture problem and the company needs to recall these cars to find the issue. If the warning light is correct, the battery appears to be overheating. My issue started over three years ago. Anyone have ideas?

Glad to see this forum, I have 2016 Sonata PHEV with 60K miles and same problem with severely reduced EV mileage and frequent high system temp warning. I’ll take it to my dealer and let you know.

 

I am having the exact same problem with my Hyundai Sonata plug in 2016 purchased in Maryland. At a local Maryland Hyundai dealer and they are giving me the run around. Dealer will not answer whether : a) the battery is covered under the 100000 mile powertrain warranty; b) have still not figured out what they think the problem is. I have told them this is clearly a common problem based on this listserv...Has anyone's dealer clearly told them it is a battery problem and what happens if you keep driving the car without anything being fixed?

 

If you are the original owner there is a lifetime battery warranty regardless of milage. As far as driving with the issue unresolved you run the risk of sudden loss of power to the powertrain, both hybrid electric motors and the ICE, and shut down of power braking and steering. That could present quite a safety issue if at highway speed on a multi lane highway.

 

These are some pretty big issues and safety ones at that. I supposed there just aren't enough complaints to document a recall... Sad part is that even with the worlds best warranty if they don't have parts or expertise, what is the real value besides hope and false sense of security based on advertisement?

 

My point exactly. Also if Hyundai refuse to do a buy back and the warranty replacement of the PHEV battery is not completed I have a 3600 pound paper weight with no value towards purchase of another vehicle to replace it. This was my 5th Hyundai and until now had loved the reliability of the brand. I still have a 2012 Accent with 131k miles, still a daily driver and has saved my bacon since Hyundai has not provided a loaner. I am just about to embark on a 28 day road trip and the Accent with that milage and limited space for 2 people and dog requires I rent a larger vehicle which Hyundai will not reimburse until repairs completed (if Ever) on my PHEV sonata.

 

I'm just here to add a "Me Too". Same issue, 2016 Sonata PHEV, same message. I haven't taken it to the dealer yet, but I'm going to get that ball rolling now.

 

Here’s an update on my situation. I took my car in last week and gave them a copy of the posts from this forum. After 2.5 days of diagnosing the issue with Hyundai engineering, they determined the generator needed to be replaced. I spoke with the Hyundai dealer hybrid tech directly. He said the battery was tested with no problem found. I also asked him about the range loss and battery degradation. He explained it was due to battery memory. It’s the nature of any lithium battery, such as a cell phone, but worse for hybrids due to constant shallow cycling which I also read from various articles. The issue increases over time especially after 5 years. The tech said the battery can be retrained with deep cycling over time, but it takes changing charging and driving habits. I’m getting 20 mi EV range which is 71% of my initial range. The battery has a warranty of 70% for degradation during the warranty period, but I don’t know how to prove the loss is due to memory versus degradation. I’ll cross that bridge next. Perhaps they can provide to me a battery test report. The dealer set me up with a loaner and my car is expected to be ready this week after the part arrives. Everything is covered under warranty. I’m skeptically optimistic it will fix the issue, but worth a try since the alternative could be waiting several months for a new battery. I’ll post again if the issue is not resolved or if the warning message no longer appears after a couple weeks.

 

Sounds very sketch because Lithium cell are considered having much less memory effect compare to MiMh/NiCd cell. Try asking them to do the deep charge cycle for you in the shop and tell them you expect the capacity to be restored when picking up the vehicle. The generator should be able to be tested like all other alternators for output voltage and current, since it's inverter's job to feed high volatage DC to battery.

 

Thanks for the suggestion. I‘ll request the deep charge cycle. They said they tested the generator which is why they determined it is the cause. I agree it seems sketchy.

 

Update to my previous post. They said they "solved the problem" and changed the cooling fans. They charged me. First day back from shop, i received the same error message. I am calling and filing a complaint with national Hyundai customer service. I suggest a number of us try this method. Has anyone on this list serv actually gotten the problem solved?

 

I think our best way to resolve this issue is to do what ADH suggested. I am going to call the National Hyundai as well. I am so tired of going in for the sonata hybrid plugin. Yesterday a new light came on saying the inverter needed coolant. What? I just had the big 700 dollar service where they were suppose to check all fluids. At least I was not charged for the coolant.haha Driving home yes the Hybrid warning came on. I am at a loss for words.

 

I picked up my car 2 days ago. They replaced the generator and ran it for several miles without getting the error message. It was all under warranty. I’ve charged the car once since picking it up and drove it to zero with no warning message so far. Still too soon to tell if the issue is resolved, but so far so good.

 

Does the full EV range restored?

 

Following
I have a 2017 Sonata PHEV with 24,000 miles with the same issues! It is at the dealership now(since June 14) I have been trying to get them to fix it for a long time with no luck.

 

I did contact the National Hyundai complaint and received a call from a service agent last week. She called me yesterday to let me know that she is still looking into the matter. What the heck? She said she had tried to call my dealership with no results so I called the dealership and they stated that they did not receive any message from them. As soon as I got back to my email, I received another email stating that I now had a new service agent who would contact me in a few days. It feels like a run around. I told the last agent to look into this forum to see that people across the U.S. are having the same issue with not fix. I will keep everyone posted but please contact them asap with this issue. I appreciate it.

 

Can you please post the phone?

 

After the generator was replaced, I did not get the alert immediately. Unfortunately the alert has now reappeared. I’m taking it back to dealer this week.

 

Just got off the phone with the representative who wanted me to take to car to another dealership. It has been four years of this. I explained to her that there are other people across the country with this issue so why go to another dealership when no one across other dealerships have found the issue. She asked me what I wanted and I told her to fix the car or buy it back. Truly, I told her that I wanted to keep the car as it is paid for but am tired of all this!!! Please contact the national hyundai complaint so they know there are others with this issue. I will continue to keep you posted.

 

After I got my car back from replacing the generator, the alert came on within a week. I took it back to the dealer. They had it for 2 weeks and we’re unable to see the alert occur. The dealer provided a loaner because it’s related to the battery (although they can’t figure out the root cause) which is under warranty. I picked it back up and it happened the next day. It has appeared twice in 2 weeks since I picked it up which is less frequent than before the generator was replaced. I plan to take it back again. At this point it is just a nuisance.

 

Make sure you take pictures and document when these errors occur and pop up. They are good at not seeing proof for themselves. The nuisance may turn into a bigger issue down the road.

 

I brought my car back in on july 18. They had replaced the fan the first time. As I indicated in previous post, error message came right back on first drive. It took them a couple of trips to recreate the error message and then recreate the error message with "a tablet connected". AFter recreating the message for themselves, they have brought in a "national Hyundai engineer" so I get the sense they are still trying across all our cars to figure out the problem. Apparently, they will now be fixing the "water pump for electric vehicle". Based on these postings, seems like Hyundai has replaced a lot of different things with no clear resolution. I do think that filing the national complaint on the Hyundai reporting system has somewhat escalated things. But things are still moving at a glacier pace across our numerous complaints...

 

Yes, I think that people contacting the National might be helping. They finally gave me a rental car on Monday and said it might be the battery. I have told them for over two years, it has to be the battery but then I am just the customer. Oh, by the way, there are two water pumps of which both of mine have been changed with no change to the indicator light. At this point, I am thinking about doing a lemon law against the company. truly, I am fed up.

 

An update from the guy who started this discussion...

My Sonata has been sitting at the dealer for over 4 months now and I just got an updated date for my battery replacement: October (with installation in November).
Their excuse is "raw materials shortage". Since I'm in the electronics industry, I can believe this - so I'm OK waiting. (Especially when others are having trouble getting Hyundai to agree to a replacement in the first place).

I did, however, take the opportunity to complain about my loaner (a Tucson SUV that gets about 23 mpg). They said they might be able to give me a Kona Electric - which would be fantastic! I'm keeping my fingers crossed...

 

There is nothing safe about driving a vehicle (with documented issues) that can shut-down while in motion let alone leave you sitting on the side of a road.

 

Which happened to me. I wasn't stranded, but the car told me to pull over RIGHT NOW. Luckily, I was rolling to a stop light, so I shut the car off and started it back up during the red light and it behaved itself after that. But that was the last straw that convinced me to pester the dealer again...