Emajinatio

"Makes you think all these issues with hesitation people are having could mainly just be a bad transmission. It is the first 8 speed transmission ever by Aisin. By harsh engagement do you mean just a typical hard shift? Only between 15-20 MPH, never at other steeds? Was it consistent?"

Harsh Engagement was a term the mechanic used. I was not aware of the terminology lol. I informed them that my car seemed to coast and then jerk into gear after being in park. Every single morning, without fail, since the purchase of the vehicle in March, the car jerked into gear always when I accelerated to approx 18mph. Initially it only occurred around 3x in a given day and the coasting would be maybe 2 seconds, before jerking into gear. As I continued to drive the vehicle, in May it was occurring about 20x in a given day and ALWAYS first thing in the morning, and the length of "coasting" grew to be 6-7 seconds before jerking into gear.

I would say maybe 3x did the coast/jerk pattern occur at speeds between 30-50mph.

So once the mechanic rode with me, and I was driving the dealership area, I made sure to keep my speeds below 10mph. Once I hit the street, I pressed the gas and began accelerating and right at 18mph, the car did not fail me and it coasted and jerked. The mechanic said, I've seen enough, lets go back to the dealership.

Hope that helps.

DMPesso

Thanks for the explanation. That literally sounds like the gear hunting I’m experiencing. If I’m driving and take my foot off the gas at certain low speeds the car jerks up and down into gear and then coasts again. Foot isn’t on the gas though. If I accelerate regularly with my foot on the gas I don’t get a hard shift. By coasting and then jerk into gear you much you mean only when your pressing the gas right? That The rpms go up very high before it shifts ?

Emajinatio

Yes exactly

Cocal

Aisin has a stellar reputation and some makes charge xtra if you want to have it in your vehicle, I don't think it's the tranny "per se"
In the case of the poster that had it replaced we don't know what the previous owner did or didn't do, good for him that it was resolved.
In our case of hesitation I think it's due to the absurd quest of "better mileage" where the tranny tries to up-shift as soon as possible and then back to a lower gear because the higher one wasn't right and so on; I've seen this in all makes. The best way to solve this is to go in "sports" mode where the economy/mileage is not taken into account bt the tranny and it can alt last operate the way it was intended.

DMPesso

Yea that’s a different issue then this gear hunting we all have. Hard and delayed shifting is always the first sign of the transmission about to fail. I had an Acura TSX that shifted hard until the transmission finally failed at around 90k.

Couldnt have said it better. What makes it obvious is the gear hunting going away when in sport mode. I can live with that. If only we could program the car to stay in sport mode all the time. His problem was different then. What other makes have you seen this on?

GSFRX350

Yes I'm sure that's the reason too - I'm in Australia so not sure about you guys but isn't fuel economy over there a big deal? Is fuel economy something that's highly regarded in the purchase of a car?

Cocal

I can speak for myself only and to me fuel economy matters up to a point.
CAFE mandates a certain fuel economy for the whole fleet and manufacturers try to oblige and most of the time it's a compromise between economy & driveability, since in "normal" mode generally it's not good, but that's how the vehicle is tested for CAFE, they've added the Sport mode so that one can drive without concern for economy, not that it uses that much more.

Now if you were making a living with your car then fuel economy would become a lot more important.

ysr84

I went to Lexus dealer (Oakville Lexus) GTA (Greater Toronto Area) and they did a regular oil replacement with filter. I told them about the hesitation issue and they applied some kind of software update which they said was required. However, i havent noticed much difference in the car driving. My issue is not similar to what FASTFORD and others were dealing here (no acceleration from start). My issue is more of hesitation in gear 3 to 4 or 4 to 5. Then when coasting at about 70 km/hr if you accelerate its not responsive but when you hit the pedal it will drop gears and give you that acceleration.

My fuel economy is amazing (better than my buddy's 2018 Rx with less kms). When i drive his 2018, I dont notice anything however his is 15,000 kms or so which makes it relatively new. I think i will take some more information from this thread and take it to my dealer. Last thing i want to do is a transmission swap (Already at 79,200 kms). Scary since i will be out of warranty soon. Although i think transmission is covered uptil 110,000.

Thanks will keep posted what happens.

flashCLXS

The sun will shine on our side of the fence!
Vehicle Bucking on 1 - 2 and/or 2 - 3 Upshifts and Surge Between 0 - 46 mph

robotbelle

Does anyone go to dealer for this one? I am planning to go there today.

robotbelle

Just have updated on this new TSB. I went to my local dealer last week. They performed the update and definitely the new software solved the issue that we have been long talking about. Now, the car drive much smoother, no jerk and feel more powerful to start from stop light.

Googs

which model and year do you have?

robotbelle

RX350 2018, nav, premium package. The car drive is ok before the TSB, but I still want dealer to take a look to make sure the software up to date. They did it and it drive great now, better than before.

Rlh4eva1

Apparently there is new software available for this issue. I had my update done last week and I am sooooo happy with the results. Seems they got it right now.

DMPesso

A different update besides the usual TSB? Or the same one everyone used on this thread?