Interesting.

 

Sounds like what happened to me. Try disconnecting the battery to see if it comes back. I took mine back to the dealer when I discovered this. If I knew all you had to do is disconnect the battery I would have done it myself. By the way, the hesitation problem has not been fixed either. Wait till it revs up to 2800 and won't change gears...That's when I knew something wasn't right.

 

Apparently the instruction don't say to do the battery. However, any software upgrade requires a reboot. Yes they should just know this!

 

Must be what they installed when they said they did a firmware update. More responsive that before.

 

I look at the TSB and my 2017 RX350 did not fall under the VIN# mention on the TSB. I been using Regular since I got the Car in Nov 2016 (current miles ~5k). Last 2 fill ups I decided to put Shell 91 and can see a marked improvement in the hesitation and knocking.
I am due for an oil change in few weeks I will ask the service advisor abut this TSB and should I get it done even though my VIN# dosent fall under the mentioned range of VIN#s.

 

I dont understand why you need to disconnect the battery. I use to load different tunes in my Challenger all the time.
It would just overwrite the existing tune. The eproms In these cars are fully erasable and can be written over
many times. All their really doing is loading different parameters in the TCM. Should not require a battery disconnect.

 

Hi Guys. My 2017 RX comes with the TSB applied. However, my MPG is terrible. Lexus says i should be getting 12.2 l/100 in city and 8.9 l/100 on hwy. I am getting 14.5 in city (driving in eco with a light foot). A friend of mine has the RX and without the TSB, he is getting the advertised MPG. I understand that driving habits matter a lot and all i can say is that i used to drive the ES 300H before and have managed to get 5.5 l/100 - so yes, am light footed most of the time.

I am wondering if anyone who has applied the TSB is noticing changes to their MPG?

 

Not sure if the TSB would matter. My 2016 falls in the TSB range, but I haven't gotten around to getting the TSB applied. My mileage in strictly city driving is just as bad as yours. Idling and hills are a killer for the mileage. I did notice that mileage varies quite a bit depending on the type of gas I use though. I usually alternate between Chevron, Shell and Costco (mostly 91, with the occasional dip to 87 just to test things out), and notice that Chevron 87 will give me mid 14's; Chevron 91 does low 14s; while Shell and Costco gas gives me low to mid 13s. Same driving route most weeks.

I'm beginning to really regret not getting the Hybrid. Had a loaner CT200h the other day (I know, different car) and on the same daily route I would take with my RX, I was probably doing 3L/100km, while my car is happily chugging 13L/100km...

 

Sounds about right to me. I probably get the same city driving and high twentys on the highway.
For me it averages out to about 21mpg. It is a heavy vehicle.

 

not sure why Lexus requires it but it does. Unless you like not having your sport and sport + modes working.

 

And the custom mode disappears completely.

 

What infuriates me the most is hat Lexus knows that there is an issue because the later 2017 models do not do this as consistently as 2016s. Clearly something has changed and the TSB was an attempt to fix the issue but it's not a complete fix. So what is it Lexus, software or hardware or both? No one should let Lexus and its dealers off the hook.

 

I dont know why they just didn't leave the 6 speed Auto in there. I have been driving mine exclusively in manual and hold each gear out to about 2500 rpm's and keep the rpms around 2k. That way Im never in the 1500 rpm range where I get some vibration. It performs so much better and never drones and no hesitation. Now For the interesting part, gas mileage, I have seen little to know difference. Still getting around 21mpg in mixed driving. Im pretty sure this is the way I will need to drive it for the remainder of the lease. Really don't believe Lexus is going to do anything and driving it in Auto feels like a sluggesh 4cyl. Definitely not what I thought this car would be like. Should have went for a long test drive before my purchase.

 

I have a 2017 model. The last several digits in my VIN is larger than those in TSB. Does that mean I should have the update already?

 

So, I had the ECU update connected skit a month ago. Right after the update the drone was almost completely gone and the car drives and shifts like it should. The only issue was that my F sport drive modes were gone. Went back to the dealer and they fixed that. But I'm not seeing any more issues after the update, yet. Are you still having issues after the ECU update?