Hard press on accelerator while on the onramp yields downshifts, high rev's but no acceleration.

[Burgie]

2023 GV80 3.5 w/18,000 miles. This issue occurred several times within minutes. Upon entering the on-ramp at approximately 30-35 mph and pressing firmly on the accelerator, the car downshifted and the engine revved without any power increase or acceleration. After gradually reaching a speed of 65 mph and pressing hard on the accelerator, there was a "click" in the pedal after pressing 3/4s of the way down and the engine downshifted, resulting in high RPMs but no speed increase. It seemed as though the turbo was not engaging, providing no power, only noise. Running at freeway speeds for the next ten miles, I pushed hard on the accelerator only to get down shift, high rpm but no power. Stopped for lunch, returned to the car and everything worked as designed. Any ideas?

 

[steveinarizona]

Could the car have been in the middle of a download or update at the time? That is the only thing I could think of that might cause the problem but then go away when you restarted the car.

 

[Jhon]

Just a thought...Is there any chance you hit the shift pedals on the steering wheel by mistake?

 

[G-762024]

Just a thought...Is there any chance you hit the shift pedals on the steering wheel by mistake?

Nope, did it several times

 

[Burgie]

Just a thought...Is there any chance you hit the shift pedals on the steering wheel by mistake?

no, I also have a C8 and well aware of paddle shift arrangement and applications, thanks anyway.

 

[Husky]

Sounds like maybe a fuel delivery issue. Even without the turbo, it should have been accelerating.

 

[Husky]

How does it respond if you do use the paddles to shift manually and try to accelerate?

 

[Burgie]

How does it respond if you do use the paddles to shift manually and try to accelerate?

It didn't respond when I clicked the upshift and only shifted once I let way up on the acceleration. Then you could slowly accelerate as long as it did not down shift. If you pressed down on the accelerator again, it would down shift and rev but went no place. It hasn't done it again since the other day and performs as expected. In the Corvette it will hold the lower gear but shift once the paddle is accessed due to programing. Most important, both cars will always accelerate in speed, this time the Genesis just revved and no forward acceleration.

 

[Husky]

Not sure what you meant.
If you manually downshift a great (not upshift) and press the accelerator (but not hard enough to force a downshift), does it accelerate or just rev higher?

 

[Burgie]

Sorry, pressing down slightly on the accelerator resulted in a gradual speed increase. Pressing firmly down on the acceleration while moving about 30 mph resulted with an automatic "click" felt on the accelerator pedal and the car downshifted. Upon downshifting, the rpms increased to the area of 5500 rpm but the vehicle did not accelerate forward even with manually hitting the shift pedal to up shift.

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[Husky]

Sorry, I'll try again. I was asking if the behavior was the same if you manually Downshifted and tried to accelerated, vs downshifting by mashing the gas pedal. It should be, but who knows.
Is it possible that it's because when you downshift and the revs go up to around 5500 that it doesn't seem to accelerate because you're well past the peak torque and getting closer to redline (although I would think that should be about 6500, but I'm not sure about your motor).

 

[Burgie]

I understood what you are saying but the issue is in the downshifting. Manually it will down shift one gear but not into one that would cause an over rev. I have the twin turbo 6. It all seems to work fine now and just another of those glitches like those that make your instrument panel go black or your screen black out. A lot of those are caused by low batteries but in this case, we had been driving for over half an hour. I did have the auto stop bread clipped as the only thing different but it had been that way for months.

 

[Husky]

Ah, I see. I thought you could downshift multiple gears, if needed, like my 3.3T G70. I can do that to get the revs to 5500 (which is not an over-rev). Yours may be different.
Glad it's working normally for you now (or at least most of the time, haha).

 

[secondo]

I had a very similar issue (22 2.5 prestige model) that was fixed under warranty. They replaced the fuel pump and it was instantly fixed. For me only if I floored it the car would suddenly stop accelerating, but the engine would rev. If I accelerated gradually the problem did not occur. It happened at almost the same speeds every time (I think 40mph was one of those speeds, but it has been a while). Here is a thread where the topic came up at the time. One dealer had it for 3 months and couldn't figure it out, I moved it to a new dealer and the next one said they couldn't understand what was wrong with the first dealer because they hooked it up to the computer and the problem was obvious. They fixed it the same day.

Here is the thread where we talked about it and it may have details I've forgotten....

my similar issue is in this thread