Hello all. I've got a 2011 ISF with 60k miles on it that has been exhibiting a "bogging down" at random times that has been happening for about a year. It seems to be occurring more frequently over the past few weeks/months. Here is an example of what happens in hope that someone here has experienced this and found a solution. Last night we were getting off the freeway on to a long loop that swings up to an overpass. It was in 8th gear as we got off the freeway, but didn't shift down as we came around and stayed in 8th as we slowed and then gave it gas as we swung around - bogging down. It doesn't cut off, but you can feel it 100% when it happens as the fuel input seems to be occurring, but the transmission isn't shifting as it should - maybe a solenoid? I've had this happen on straight, level roads as well. The transmission fluid level is fine as I had that drained and filled last week by Lexus of Roseville (CA). It was doing it before they did that, but I wanted to have them drain and fill as I plan to keep the car long term. The one solution I've found for now to avoid this happening is to drive in manual. However, that isn't something I want to do all the time. There are no codes and I've viewed and recorded live data. Of course, when I was recording live data from the vehicle, the issue didn't happen. My wife doesn't want to drive the car now since she views it as a safety hazard, which it is. My local Lexus dealer is great as is my service advisor, but they don't know what to do without data on the car giving them some indication as to what is wrong - aka a code. I'm going there tomorrow to drive the car with the shop foreman, but I'm guessing it won't do it then just based on prior experiences. The car is under warranty from Lexus still as I purchased the extended warranty from Lexus which is good until 120k miles or June of 2020. I've pulled the fuses to reset the computers a few times with no remedy, cleaned the MAF, throttle body, new intake filter (OEM), etc. I've searched the forum for the issue and on Google, but haven't been able to find something similar. Thank you!

 

it sounds like the transmission , there are a few members having those problems and got replaced.

 

I know how frustrating you feel right now, especially if you always do a spirited driving. I did a lot of things to my F but never encountered this problem, the only thing when the transmission is cold the shifting kind of slow. Btw, Im planning to get that 2012 steering ECU at Lexus of Roseville,im here everyday at Teriyaki Station across Folsom Outlet.

 

It is frustrating and it is my first Toyota product so I'm a little bummed (came from BMW). However, I'm hoping there will be a resolution somehow. I'm just going to keep monitoring it and hope a code or fault become evident sooner than later so Lexus can replicate it as I would hate to sell it. Yes, I've experienced the transmission flare during the 2 years I've owned the car and this is totally different. The best way I can describe it is being in the wrong high gear in a manual transmission and pressing on the gas. Next time I'm in your neck of the woods, I'll swing by.

 

Sorry to say, but they didn't set the fluid level right. When it is low, it's always a nightmare. When it is right, you won't believe the difference. AMHIK.

 

Glad you have the extended warranty - Since I know zero about transmissions, I would try disconnecting from the battery (vs pulling fuses) as a last (no cost) ditch effort. If it works in manual mode - it almost sounds to me like could be throttle position related? Good luck.

 

Update: Just returned from the dealer where the shop foreman drove around in the car with me. Of course, nothing abnormal happened. I mentioned the transmission fluid level concern. The shop foreman suggested they reset the transmission control module (with techstream I'm assuming). I told him that I had just disconnected the battery to do that and they didn't think that was the same as using their system to do it. Therefore, I told them to go ahead. Plan is to now monitor when it happens again - gear, speed, situation, etc. The next step in my mind is to confirm the fluid level when it happens again. They've been a good dealership to work with in the past and I've got a great service advisor so we shall see.

 

Can you expand on the symptoms of when it's low?

 

Flare and sticking in a gear far longer than it should with no indication the transmission will shift.