GSFRX350

Okay, getting a reset done in your case could be of benefit. You don't know how it was driven before (hard, gentle) and your driving could be totally different. The transmission in this car learns your driving habits and adjusts. A hard reset brings it back to a factory state and will start learning again for YOUR driving. The easy way is to just disconnect the battery for 30 minutes, BUT you will have to reset all your settings (seats, audio, steering wheel, etc).

In case you don't know there really isn't a "problem" or fault with the car it's just how it drives with a priority on lower fuel consumption. In Normal Mode it changes up gear sooner than ideal for performance but better for fuel consumption. Put it in Sports Mode and it holds the gears longer. making it feel more responsive, smoother BUT hurts the fuel consumption. The TSB that was issued changed the mapping of the software to be more like Sports Mode in Normal Mode.

The thing with this car is it's a luxury car, not a sports car and many people will only drive it gently, while others want to punt it along hard. There's just a massive difference between driver types. I drive gently around my home town, it's flat and not busy and the car feels fine in Normal Mode. When I go to a city where the pace is fast and there's hills using Normal Mode means it starts to jerk around trying to find the right gear. That's when I throw it into Sports Mode and it feels much better.

Something that seems to help, although I haven't done extensive testing is to let the car warm up for a couple of minutes in the morning BEFORE moving at all. This means your first movement is with a warmer engine which will change it's behaviour compared to a cold engine.

gadgetman1

Go have the TSB completed. Nothing ventured, nothing gained. The last RX 350 loaner I had was a horrible dog. That transmission couldn’t decide what gear it needed, even on flat roads. It was pathetic & that’s an understatement. Good luck & let us know what you do.

Nail34

'17 fsport, when I got it I was ready to sell it because of the shifting pattern. Get the TSB, it's free at the dealership and for me it cleared up most of the hesitation, at the very least I wasn't constantly thinking about it. I drive in m-mode at some point in all of my drives (I live in the hills) except for short trips around town. The only shifting problems in m-mode is me. lol

Emaniat

Does it help with a harsh 6-5 downshift? Mine has always slammed since new most of the time ever since new. It’s worse in sport mode.

Nail34

I presume your talking about manual mode. Yes you are correct, for some reason downshifting into 5th is harsh and clunky as opposed to any other shifts, however when shifting rapidly while going down a long hill it's not so bad as opposed to just slowing down for an exit. I guess I'm just getting used to it.

Emaniat

Yes… Exactly.

joytoy999

The reset did not help in my situation and upon advice from this thread, I ordered the Power Tune High Performance Tuner Chip off Amazon for $90 and its the only thing that has made a difference. Don't get me wrong, I do not love my car now but at least I do not HATE it like I did before.

BensonTT

Any different in fuel consumption?

joytoy999

I have no idea....sorry, I do not usually track my fuel consumption.

GXGSAm

Hello All,

I bought a high mileage CPO 2016 RX350 recently and after 1k miles of driving, I went back to the dealer and asked to TCU reflash. Well, that didn't work! I was experiencing erratic shifting when I first drive in the morning, when the transmission is cold. Then when I am on the freeway and the car is in normal operating temp., I feel some sharp shifting thuds when I let up on the gas, and more thud when I quickly press the gas pedal. It was such a unpredictable 8-Speed transmission as far as learning how/doing everything to make the shifting right!

Initially, drained some transmission oil then rechecked the level according to temp setting and letting out some excess oil. That also didn't work, shifting issues continued.

Then I drained the transmission oil again after a few hundred miles, but this time around I purposely measured the oil that came out of the 17mm hex plug - a bit less than three quarts of oil came out as measured.
After realizing what I have experienced doing transmission oil changes in the past, I put it a little over three quarts of oil in the transmission.
Approximately "3.2" quarts of oil later was added and without checking the oil level at this point and what a surprise - everything is back to normal (smooth) shifting is evident (so far).

This weekend, I will disconnect the battery overnight to refresh everything, just to make sure after the reboot, this RX starts with a fresh memory, relearning everything according to my driving inputs.
My theory is, having owned different Lexus vehicles over the past twenty-five years, when it comes to transmission oil drain and refill, the magic number is 3.1 - 3.2 quarts (for me that is)!
I also intend to do one more drain and refill (D/R) after 10k miles of driving, then follow the 50k-60k mile D/R interval.

703

Disconnecting battery doesn’t reset anything.

GXGSAm

You’ll be pleasantly surprised if you try.

GXGSAm

My “own” experience with Lexus vehicles’ transmission shifting issues are due to incorrect oil level. When I followed my own way of fixing it, I always fix the problem. One the worst experience was buying a 200k plus mile 2007 IS250. I had to replace a few solenoids, replaced the filter, and drain and refilled the transmission twice and the shifting was better/smoother than the 2013 IS350 FSport I gave my son.

703

i know exactly what it does. Fully documented in the service manual. Don’t need to try.

GXGSAm

after changing my transmission oil A few days ago as described, then unplugged my battery Friday night. Driving the RX All Saturday felt like a totally different vehicle, shifting was very smooth, no hesitation, and I didn’t feel any erratic gear shifts. As for the effect of unplugging the battery, I lost all my programmed settings on my seat, side view mirror tilt on reverse, side view mirror fold-in on car lock, etc. My wife wasn’t happy she had to redo hers too. Long story short, some things happen when you unplug your battery for a while. Speaking based on my own experience, I am not saying it helped with the much smoother shifting, but I proved to myself (only), for having worked on my own Lexus vehicles in the past that my procedures worked for me each time and I honestly and proudly can say, with the intent of informing others my failures and successes owning a Lexus.