At a red light engine must be restarted

[Jetsi]

Occasionally after stopping at a red light in my 2025 GV80 and while sitting in traffic, when the light turns green I take my foot off the brake the engine does not restart and the car starts beeping like I'm about to hit someone. I must then put the car back in park and restart the car before proceeding through the intersection. There might be some sort of screen on the dash, but I'm too freaked out when it happens. Anybody else have this problem?

 

[NVQB10]

Occasionally after stopping at a red light in my 2025 GV80 and while sitting in traffic, when the light turns green I take my foot off the brake the engine does not restart and the car starts beeping like I'm about to hit someone. I must then put the car back in park and restart the car before proceeding through the intersection. There might be some sort of screen on the dash, but I'm too freaked out when it happens. Anybody else have this problem?

Have you checked to make sure all the sensors around your front bumper are clean of dirt and bugs?

 

[EdP]

Occasionally after stopping at a red light in my 2025 GV80 and while sitting in traffic, when the light turns green I take my foot off the brake the engine does not restart and the car starts beeping like I'm about to hit someone. I must then put the car back in park and restart the car before proceeding through the intersection. There might be some sort of screen on the dash, but I'm too freaked out when it happens. Anybody else have this problem?

It should be at the dealer already. Have they had any comments?

 

[Jetsi]

To answer the two replies, Yes the sensors are clean and free of bugs or dirt having just washed the car the day before my posting. My 2025 GV80 is due for service in slightly over 1000 miles and after talking with the service department, they said they would have to keep the car for a few days to try and duplicate the problem after plugging the car in and looking for the incidents. So I'll wait to bring it in for it's first service. One caveat in this situation is that the start/stop is active when it happens. To my knowledge it has never stalled out while the start/stop has been inactive. So for the time being I will drive with it inactive.

 

[mikec]

Sounds like the switch at the brake pedal is flaky - not realizing you've released the brakes. Sometime when you feel its safe to test - like maybe driving in an empty parking lot - come to a stop as you normally do, with the start/stop system enabled. Let the engine shut down... now slowly release the pedal. Do this a few times and see how often the start/stop fails. When the brake pedal is somewhere about 1/2 inch away from being totally released the engine should restart. I wouldn't be surprised to hear your car doesn't restart sometimes if the switch is improperly adjusted, balky, or dirty (not likely on a brand new vehicle though). Perhaps slamming the brake pedal a bit - to shake up that area - and then releasing it normally would work around a flaky switch. Or the spring that lifts the brake pedal is missing/broken and, when you release the pedal, the pedal isn't lifting far enough to release the switch. Apply the brakes a little bit (about what you'd use when coming to a stop sign in a residential neighborhood), then very slowly release the pedal. Once your foot is totally off the pedal, and it thus has returned to what it thinks is the travel limit, try lifting the pedal with your toes... if it moves at all then the pedal/spring/switch area needs adjustment/repairs.

I had a loaner GV80 that didn't have the start/stop disable switch on the dash; I found holding the pedal just enough to keep the vehicle from creeping while in Drive was enough to keep start/stop from engaging; pushing further engaged stop/start. My 2021 will re-start the engine with the pedal released to about half to one inch of travel. That's the proper switch adjustment.

mike c.

Edit: Hyundai/Genesis (and likely Kia) use a lot of electrical signals to control what used to be cable operated on cars. For example, the engine throttle is "drive by wire" where a sensor in the throttle pedal measures how far it has been pushed and the computer drives a small electric motor to move the throttle plates. Electrical systems tend to have many more components than simple mechanical systems and electrical parts tend to fail far more often than mechanical parts. The common engineering solution is to use multiple sensors so the computer can verify "both sensors agree the gas pedal is pushed half-way... open the throttle half way." That way a dying sensor (or wiring failures) don't make the computer think "gas pedal is fully depressed! Go full throttle!" When the sensors do not agree, error codes are set and the computer has to use various backup logic schemes to decide which sensor to believe... typically resulting in low power/low acceleration "limp home" modes. If the brake pedal switch outputs don't agree that might be the source of the beeping.

 

[mikec]

Thought about this a bit during the day... when your car won't automatically restart, are there always other cars around or has it happened when no other car was nearby? I wonder if the proximity sensors are seeing signals from other cars, making your car think "we're about to run into something" which prevents it from restarting. Those prox sensors are from a supplier to Hundai/Genesis/Kia and are shared with several other car brands. It's not uncommon for some other car's transmitter to be picked up by your car... which your car interprets as a reflection of its own signal making it think "something is nearby. Cry wolf." I get numerous false alarms when parked at traffic lights from various car brands, especially Ford trucks. I don't let the idle stop/go system run on my car so I've never experienced what it might do, or not do, when the prox sensors are triggering dash warning symbols and the audio beeps.

mike c.

 

[Jetsi]

Always happened at a stop light with cars all around me. I don't remember if it has ever happened with me being the first car in the line with cars behind and on either side of me.

 

[G-113576]

It's possible that your AGM Battery isn't sufficiently charged to restart the engine. FYI - I am currently dealing with this issue waiting for a callback from a Genesis Case manager about why my 2022 G80 3.5T battery sensor didn't warn me about its insufficient charge state given that Genesis of Scottdale, AZ replaced my battery Oct 25, 2025 because of the same failure to start. FYI - Tech told me I should drive more or connect a trickle charger every night to keep the battery above an 80% charge.

 

[SoCalG90]

It's possible that your AGM Battery isn't sufficiently charged to restart the engine. FYI - I am currently dealing with this issue waiting for a callback from a Genesis Case manager about why my 2022 G80 3.5T battery sensor didn't warn me about its insufficient charge state given that Genesis of Scottdale, AZ replaced my battery Oct 25, 2025 because of the same failure to start. FYI - Tech told me I should drive more or connect a trickle charger every night to keep the battery above an 80% charge.

I was thinking it could be the battery also. And a trickle charger every night? That is what an alternator is for. Why is it that cars sitting on the lots don't need trickle chargers all the time. Sounds like it could be something else.

 

[joegr]

It's possible that your AGM Battery isn't sufficiently charged to restart the engine. ...

Yet, he says it starts when he puts it in park and presses the start button. The engine would not turn off (automatically) if the battery charge were low.

______________________________

Help support this site so it can continue supporting you!