New to the club! I have been having this issue since I bought the car, used with 13k miles on it. Every morning when I go to work, this happens

Here is the clip, the surge will be 2-3 seconds before the vid end.
https://youtu.be/822tlxsU_m8
Video

 

Welcome to the forum!

From the vid the temp gauge is at C, so the vehicle is still cold, and as the speed is increasing the vehicle is upshifting. Not sure if you are linearly accelerating or if you backed off the gas a tad after the turn.
Nothing really looks out of the ordinary within the 7 second vid.
Does it still have the issue when the vehicle is at operating temperature? Cold cars do funny things that go away when they warm up.

 

Automatic down shifting because of slow speed or the car is still cold so rpms might go up, my guess.. When I turn on my defroster my RPMs go up too, it looks fine though

 

Yes it happens only when it is cold. My pedal is on a still position, i did not move it one bit. It was a harsh upshift, like when you over rev a manual then change gear. You can see the rpm surges up while it shifts from 18mph to 20mph which isn't suppose to happen even when it is cold.

 

Probably but it is very harsh like downshifting in a manual when your rpm is higher than what it is suppose to be in. There is a TSB questionaire about it and told my dealer about that and says that there is nothing they can do about it.

NHTSA ID Number: 10179701

TT: The Lexus Quality group is looking to better understand our customers expectation regarding vehicle drivability. Specifically, we are looking at vehicle surge/hesitation condition (inconsistent acceleration) and would like to recover detailed customer voice and vehicle data.

 

So your foot is off the gas pedal when the rpm surge happens? This is from starting the car and just letting it move on its own in D and normal mode, right? I have a 2019 as well (AWD F-Sport, Canadian spec), can't say I've noticed any rpm surge.

 

About 20% pressure on the pedal. I don't push it hard when it is cold, i heard it is bad for the engine and transmission.

 

I'll watch out for this when I go out later, it's like -10C here and I'll start the car, let it idle for 20s then I'll drive gently away and see if the tach surges at any point.

 

Also, go into your gauge menu (the right button on the steering wheel that looks like two overlapping pages) and set it to show what gear you're in. Take another video of it when you're driving in a straight line and we can see when it surges, and at which gear.

In normal mode, the climate control will kick up the RPM to warm up the airflow. Maybe start the car in eco mode (which sets the climate control to eco) and see if the surge is still there.

 

I'm going to assume that your 2019 is RWD since you didn't mention it being AWD.
The RWD has an 8-speed tranny, so you can expect more shifting going on versus those of us that have the AWD, which is only a 6-speed tranny.
When the vehicle is cold things can happen that go away when it warms up.
When you bring the car to the dealer it's already warmed up form the drive, so I doubt they can see an issue or duplicate the issue.

The blip in RPM on the video could be the tranny hunting for the correct gear at that moment, as it has 8 to choose from.
It's quite possible it downshifted for a nano moment and then decided it was time to upshift a nano moment later.
If you could duplicate your concern with the vehicle at operating temperature, then I'd say you have a valid issue...with a vehicle that is stone cold, to say it's an issue is likely overestimating it.
Also the vehicle has a learned drive pattern from the previous owner, which could be vastly different that the way you drive.
In time the tranny will adjust to you driving the vehicle, but if you want to speed up the process the dealer can reset the learned values so the tranny will start from scratch with you are the only driver pattern it's learned.

 

He could start it in Eco mode, and move the shifter to the left to get into manual shift mode, then get the car moving slowly in 1st to see if the surge still exists from 14 - 20 mph. That would eliminate any auto upshift logic from firing off.

 

Yes it is the RWD version with 8 speed auto, Sorry I didn't include that. Eco mode does this also. Ill try manual mode until 5th gear.

Yep dealer couldn't replicate it because the vehicle is already warmed up.

 

I'm still leaning towards having the dealer reset the memory so it clears the learned values and then drive it from there for a couple weeks and see what happens.
Realistically since the concern is gone when the vehicle is at operating temperature, this means it's not a fault in the vehicle, but rather an operating characteristic.
If the vehicle performed exactly the same when stone cold versus at operating temperature, then you'd have the perfect car.

 

I will also give this a try, this will be the 2nd time of the month i am going back to the dealership, first was to fix a pump recall and arm rest squeak. I feel like i am an *** for going back alot of times lol, but i hope it will fix it. I will update once they reset it and i will give it a few weeks. If not, it could be a cold transmission slip. I love this car and i want it to last a lifetime.

 

My 6 speed AWD is very jerky in the first gear especially in the cold.. our transmissions are older.. in the cold, not as smooth but once it heats up, it's good