2019 Hyundai Sonata Plug-In Hybrid Problems

The high voltage battery will no longer charge neither from being plugged in to the charger on the wall nor from the buikt in system onboard the car. There are warning lights saying the inverter coolant is low but the reservoir is at the proper level. I suspect the coolant for the Hybrid charging inverter is bad and crystalizes causing blockages in the inverter coolant system. My car refuses to charge for the last 2 years. After a few seconds (about 7-10) the car shuts off the charging system when plugged in. And now that summer heat us here in the South West, it will not even charge from the regenerative braking. The high voltage battery previously would maintain 10-15% charge from the gas engine and regenerative braking. Now it's sitting at 1%. Because the battery is so low the electric motor does not produce power, and the gas engine is under powered on its own. This makes acceleration from a stop light/sign sluggish, slow and dangerous. Other Hyundai EV (IONIC and Kona) and PHEV (Santa Fe and Tucson) models have had their inverter coolant flushed and replace, some with a different spec coolant. This Sonata 2019 PHEV probably suffers from the same poor coolant and needs to be flushed and replaced by the better spec coolant fluid too. This has been getting worse and worse the last 2 or 3 years. The dealer refuses to acknowledge the problem and wants to diagnose the whole system before replacing what is obviously wrong first. The inverter coolant low level alert comes on some times, but it is not low. I haven't had time to let the dealer keep my car for days while they pretend to not know the problem and refuse to accept responsibility. Hyundai Technical Service Bulletin (TSB) exist for IONIC, Kona, Santa Fe, and Tucson models. For example the Hybrid Santa Fe and Tucson TSB is Hyundai TSB 23-01-052H-1.

While driving the car it suddenly decelerated and multiple warning errors on electronics, driver assist, braking started going off then the error message of Check Hybrid Turn Engine Off came on. I was able to coast into a parking lot as the car could only go around 5 miles an hour. I turned the care off and on and the Check Hybrid Turn Engine Off remained for the 2 hours it took to have a tow truck come to take the car to a dealer. The car has 16,383 miles and prior to this there was no warning or error messages. The dealer hasn't reviewed the car yet, but the fact that it immediately, with no warning, decelerated and would go only 5 miles an hour is very risky and unsafe.

The high voltage battery will no longer charge neither from being plugged in to the charger on the wall nor from the buikt in system onboard the car. There are warning lights saying the inverter coolant is low but the reservoir is at the proper level. I suspect the coolant for the Hybrid charging inverter is bad and crystalizes causing blockages in the inverter coolant system. My car refuses to charge for the last 2 years. After a few seconds (about 7-10) the car shuts off the charging system when plugged in. And now that summer heat us here in the South West, it will not even charge from the regenerative braking. The high voltage battery previously would maintain 10-15% charge from the gas engine and regenerative braking. Now it's sitting at 1%. Because the battery is so low the electric motor does not produce power, and the gas engine is under powered on its own. This makes acceleration from a stop light/sign sluggish, slow and dangerous. Other Hyundai EV (IONIC and Kona) and PHEV (Santa Fe and Tucson) models have had their inverter coolant flushed and replace, some with a different spec coolant. This Sonata 2019 PHEV probably suffers from the same poor coolant and needs to be flushed and replaced by the better spec coolant fluid too. This has been getting worse and worse the last 2 or 3 years. The dealer refuses to acknowledge the problem and wants to diagnose the whole system before replacing what is obviously wrong first. The inverter coolant low level alert comes on some times, but it is not low. I haven't had time to let the dealer keep my car for days while they pretend to not know the problem and refuse to accept responsibility. Hyundai Technical Service Bulletin (TSB) exist for IONIC, Kona, Santa Fe, and Tucson models. For example the Hybrid Santa Fe and Tucson TSB is Hyundai TSB 23-01-052H-1.

I was traveling on a highway when a "hybrid system warning" suddenly appeared on the dashboard. Every dashboard warning light illuminated. The car began to lose power. I exited the highway immediately and the car began to have sporadic power and was "lurching." I immediately pulled onto the shoulder and at that time another warning on the dash appeared within a minute or two of the first warning that said "shut engine off." The computer screen began to flash on and of and the windows would not roll up smoothly. When the tow truck arrived the car wouldn't start and it didn't recognize the key fob. Hyundai now has the vehicle and claims the car needed a "software update", but they cannot tell me if it will ever happen again and cannot tell me why the car goes into critical failure when it needs a mere software update. This is the second time this has happened. The first time it was repaired under a voluntary recall campaign about a year ago. This is an extremely dangerous occurrence as the car loses power without warning. I was fortunate to be near an exit when it happened and able to safely get off the highway, but that was just luck. The manual indicates that a hybrid system warning means that the car can potentially go on fire.

The high voltage battery will no longer charge neither from being plugged in to the charger on the wall nor from the buikt in system onboard the car. There are warning lights saying the inverter coolant is low but the reservoir is at the proper level. I suspect the coolant for the Hybrid charging inverter is bad and crystalizes causing blockages in the inverter coolant system. My car refuses to charge for the last 2 years. After a few seconds (about 7-10) the car shuts off the charging system when plugged in. And now that summer heat us here in the South West, it will not even charge from the regenerative braking. The high voltage battery previously would maintain 10-15% charge from the gas engine and regenerative braking. Now it's sitting at 1%. Because the battery is so low the electric motor does not produce power, and the gas engine is under powered on its own. This makes acceleration from a stop light/sign sluggish, slow and dangerous. Other Hyundai EV (IONIC and Kona) and PHEV (Santa Fe and Tucson) models have had their inverter coolant flushed and replace, some with a different spec coolant. This Sonata 2019 PHEV probably suffers from the same poor coolant and needs to be flushed and replaced by the better spec coolant fluid too. This has been getting worse and worse the last 2 or 3 years. The dealer refuses to acknowledge the problem and wants to diagnose the whole system before replacing what is obviously wrong first. The inverter coolant low level alert comes on some times, but it is not low. I haven't had time to let the dealer keep my car for days while they pretend to not know the problem and refuse to accept responsibility. Hyundai Technical Service Bulletin (TSB) exist for IONIC, Kona, Santa Fe, and Tucson models. For example the Hybrid Santa Fe and Tucson TSB is Hyundai TSB 23-01-052H-1.

I was traveling on a highway when a "hybrid system warning" suddenly appeared on the dashboard. Every dashboard warning light illuminated. The car began to lose power. I exited the highway immediately and the car began to have sporadic power and was "lurching." I immediately pulled onto the shoulder and at that time another warning on the dash appeared within a minute or two of the first warning that said "shut engine off." The computer screen began to flash on and of and the windows would not roll up smoothly. When the tow truck arrived the car wouldn't start and it didn't recognize the key fob. Hyundai now has the vehicle and claims the car needed a "software update", but they cannot tell me if it will ever happen again and cannot tell me why the car goes into critical failure when it needs a mere software update. This is the second time this has happened. The first time it was repaired under a voluntary recall campaign about a year ago. This is an extremely dangerous occurrence as the car loses power without warning. I was fortunate to be near an exit when it happened and able to safely get off the highway, but that was just luck. The manual indicates that a hybrid system warning means that the car can potentially go on fire.

I was traveling on a highway when a "hybrid system warning" suddenly appeared on the dashboard. Every dashboard warning light illuminated. The car began to lose power. I exited the highway immediately and the car began to have sporadic power and was "lurching." I immediately pulled onto the shoulder and at that time another warning on the dash appeared within a minute or two of the first warning that said "shut engine off." The computer screen began to flash on and of and the windows would not roll up smoothly. When the tow truck arrived the car wouldn't start and it didn't recognize the key fob. Hyundai now has the vehicle and claims the car needed a "software update", but they cannot tell me if it will ever happen again and cannot tell me why the car goes into critical failure when it needs a mere software update. This is the second time this has happened. The first time it was repaired under a voluntary recall campaign about a year ago. This is an extremely dangerous occurrence as the car loses power without warning. I was fortunate to be near an exit when it happened and able to safely get off the highway, but that was just luck. The manual indicates that a hybrid system warning means that the car can potentially go on fire.