[GoneFishing]

Had no issues with car until 1/28/22 @ 10:45 pm. Driving on interstate and all of a sudden "HEV Warning - Do not Drive", etc. Got off interstate in about 3 miles (limped). Shut off car, and it would not restart, show ready, nothing. Got towed to closest dealer (45 miles - what a problem). Dealer found SAFETY FUSE and RELAY INOP. Replaced Safety Fuse and Relay. Also performed Aux Canister Installation (21-01-036H), Engine Monitoring Logi (21-01-023H-4), Anchor Pretensioner Ins/Label (17-01-061). Picked up car and it ran fine for couple of days. Then noticed it seemed to slip/stall when it was coming out of EV mode a few times. Wasn't really bad and not real often, but it got worse/more common. Then on 9/2/22, HEV Warning again, just as I was pulling off interstate exit. Was able to get car to apartment (1/2 mile) but it didn't have much power. Car sat in garage for 10 days. I rented a tow dolly so I could take car to dealer. When I put car on dolly @ 6 PM, the check engine light was still on. After towing it 450 miles (to my local dealership), when I started it to take off tow dolly, check engine light was not on. Dealership ran diagnostics and stated there were no codes stored (seems like and issue to me). They supposedly test drove it and said everything was fine. Again, picked up car. 3 days later, was back on interstate (my job involves travel between 2 locations 450 miles apart every other weekend), and again had the slipping feeling when coming out of EV mode. Also noticed now that the READY light would flash off, then back on. Sometimes it flashed once, twice of even 3 times, again mainly when coming out of EV mode. Noticed that if I had cruise control set when this happened, it would turn cruise control completely off. I could turn it on, but not set it, and it never turned it off when ready light would flash. The ready light flashing seemed to be worst when trying to accelerate, and car seemed to slip or delay before switching to engine power. Then today (10/20/22), when getting off interstate to go to my apartment, the HEV warning comes on again. Basically it completely shut off on its own. Seemed like total loss of power/voltage. Put in park, set parking brake, got check brake message. After about 3 minutes, was able to get it back running, back to apartment, and check engine light is on. I lost most voltage (radar detector turned off) but radio stations are still in memory. When I got to apartment, I pulled the fuse in the trunk area and reseated it. Check engine light still on. Anyone have any ideas what may be causing these issues? I don't want to go back to dealer and they say there is nothing wrong again. Most of my travel time is done at night and don't want to get stranded on side of interstate between Nashville TN and Charleston SC.
Any advice would be appreciated.

 

[lowfunk99]

Mine is doing the same thing. All the issues started after the knock sensor update. Try taking it to an auto parts store and have them check for codes. The dealers suck!

 

[GoneFishing]

I will do that. Had more issues since original post. When I got in the car on 21 Oct to go to work, the check engine light was off. I didn't think it was supposed to go off until codes were manually cleared. That really concerns me if it is not keeping its memory. Have now noticed that when I attempt to start it may take 3-4 times to get it "started" so the ready light comes on. It will chime then state "check brake" and ready light is not on and ECO gauge is still at 0, like it is ACC mode. Have tried to just push start button, hold it for a couple of seconds. Doesn't seem to make a difference. Have had times it even chimes, then will "start". Ready light is still flashing off, seems like when it comes out of using electric and going to straight engine power. Could spark plugs be an issue and maybe the gas engine is not starting/engaging soon enough? Last time it was at dealer they stated the plugs were due for change, but did not have any misfires. Maybe it is not showing misfires because the computer is not keeping codes????
I'm thinking I may be having a couple of different issues simultaneously, but they all started after the safety fuse/power relay were swapped and the software updated.

 

[torre178]

i have this happened to me too many times but you need to carry a scanner, the first time it was my 12 volt battery replace that, 6 months later the same thing, got stranded but had a jumper pack turned back on, drove home 40 miles, after one week of dealing with the same issues, had a scanner got code P070 Hybrid battery cell getting hot, go a rebuilt unit that is great getting 40 mpg's again, but now back with another strange codes U0101 timeout TCM and checked the can bus is good 61 OHMs, but cannot communicate with different modules, with this car I carry a small cheap scanner but you need the higher tech ones i rent to diagnose it but now I am kind of stuck on this one, Check main wiring connectors and check H-CAN BUs and C CAN Bus and still, I am not sure what to do next keep searching, hope this helps, thanks

 

[ldanielstn]

Had no issues with car until 1/28/22 @ 10:45 pm. Driving on interstate and all of a sudden "HEV Warning - Do not Drive", etc. Got off interstate in about 3 miles (limped). Shut off car, and it would not restart, show ready, nothing. Got towed to closest dealer (45 miles - what a problem). Dealer found SAFETY FUSE and RELAY INOP. Replaced Safety Fuse and Relay. Also performed Aux Canister Installation (21-01-036H), Engine Monitoring Logi (21-01-023H-4), Anchor Pretensioner Ins/Label (17-01-061). Picked up car and it ran fine for couple of days. Then noticed it seemed to slip/stall when it was coming out of EV mode a few times. Wasn't really bad and not real often, but it got worse/more common. Then on 9/2/22, HEV Warning again, just as I was pulling off interstate exit. Was able to get car to apartment (1/2 mile) but it didn't have much power. Car sat in garage for 10 days. I rented a tow dolly so I could take car to dealer. When I put car on dolly @ 6 PM, the check engine light was still on. After towing it 450 miles (to my local dealership), when I started it to take off tow dolly, check engine light was not on. Dealership ran diagnostics and stated there were no codes stored (seems like and issue to me). They supposedly test drove it and said everything was fine. Again, picked up car. 3 days later, was back on interstate (my job involves travel between 2 locations 450 miles apart every other weekend), and again had the slipping feeling when coming out of EV mode. Also noticed now that the READY light would flash off, then back on. Sometimes it flashed once, twice of even 3 times, again mainly when coming out of EV mode. Noticed that if I had cruise control set when this happened, it would turn cruise control completely off. I could turn it on, but not set it, and it never turned it off when ready light would flash. The ready light flashing seemed to be worst when trying to accelerate, and car seemed to slip or delay before switching to engine power. Then today (10/20/22), when getting off interstate to go to my apartment, the HEV warning comes on again. Basically it completely shut off on its own. Seemed like total loss of power/voltage. Put in park, set parking brake, got check brake message. After about 3 minutes, was able to get it back running, back to apartment, and check engine light is on. I lost most voltage (radar detector turned off) but radio stations are still in memory. When I got to apartment, I pulled the fuse in the trunk area and reseated it. Check engine light still on. Anyone have any ideas what may be causing these issues? I don't want to go back to dealer and they say there is nothing wrong again. Most of my travel time is done at night and don't want to get stranded on side of interstate between Nashville TN and Charleston SC. Any advice would be appreciated.

My daughter's 2014 did this last week 3 hours from home. I had towed to the local deal and they think it is a bad "safety fuse". Might I ask how much it cost you to get that fixed? TIA

 

[torre178]

I am an Electrical controls engineer and I would never accept that diagnostic from an auto motive repair technician, the fuse would stop working, he didnt know what to tell you, plus there are youtube videos on how to take it off takes one minute and you can buy it on amazon or mcmaster website for 35 dollars or less. The issues with the sonata is that the watchdog system they use senses the 12 volt battery levels and if it gets to low it shuts down really fast and it goes on limp mode all the codes come up U0101 are common lost of data communication. The dealer reset it and then is oK ususally the 12 volt battery is going low on charge at a particular point and it shuts down. It has happen to me like 6 times have been able to get a new battery reset the system and good to go.

 

[csonata]

Did anyone else successfully fix their problem? my 2014 did something very similar. threw codes like c1612, c1611, c1236, and c1102. dealer doesn't know what to do and wants me to pay them for hours of diagnostics and can't guarantee they will even find the problem