Auto Transmission Issue at 33k
01-02-20, 11:50 AM
#31
Driver School Candidate
Yes, it does not. The redline when you start out cold, is around 4500 rpm. It slowly works it way up to 7300 rpm and can take up to 20 mins or so to properly warm up. If you try to downshift even at modest speeds, the rev range is so small that even downshifting at slower speeds puts the downshift outside the allowable speed range. There are lots of safety mechanisms in place when the transmission is cold, which I guess Lexus did for longevity.
I don't use auto mode for two reasons. One is that the torque converter only deactivates in sport+/manual mode and I want to avoid the slushbox feel. Also, the auto mode has artificial intelligence that learns from the driver's driving habits and adapts accordingly including using the G-sensors, which is very unpredictable as it does not factor in sudden change in driving patterns.
Once it is warmed up and in manual/sport+ mode, it is a phenomenal transmission with the torque converter locked up. From someone who has been driving 6 speed manuals for 20 years and does his own heel-toe/rev-matches etc., I don't miss manual while driving the RCF as I only use manual mode in the RCF (but, I definitely keep a 6 speed manual car for the purpose of doing my own rowing).
Once it is warmed up and in manual/sport+ mode, it is a phenomenal transmission with the torque converter locked up. From someone who has been driving 6 speed manuals for 20 years and does his own heel-toe/rev-matches etc., I don't miss manual while driving the RCF as I only use manual mode in the RCF (but, I definitely keep a 6 speed manual car for the purpose of doing my own rowing).
The transmission is fine. The programming blows.
01-02-20, 11:58 AM
#32
Lexus Test Driver
Its not speed dependent... I mean first off it would be RPM dependent, but regardless lets take into account that everyone knows it isnt going to let you over-rev - The issues has to do with the transmission temp. The car wont let you shift even when you wont be above redline. Its way too invasive.
.
.
01-02-20, 12:36 PM
#33
In the Porsche world, you can get a PDK tune (Cobb for example) that snaps through the gears. It may be that a tune will only work on a true DCT and not a torque converter slushbox. I don't suppose there is any aftermarket solution for the Lexus 8 speed?
01-13-20, 05:15 PM
#34
Driver School Candidate
Happened to me again the other day.
Car in Sport +, manual mode - wouldnt shift into 8th at 74 mph. Tried the paddle and shifter 15 times... waited 30 secs and tried again... finally worked on the 5th or 6th try.
Theres no rhyme or reason to this.
Car in Sport +, manual mode - wouldnt shift into 8th at 74 mph. Tried the paddle and shifter 15 times... waited 30 secs and tried again... finally worked on the 5th or 6th try.
Theres no rhyme or reason to this.
01-13-20, 09:01 PM
#36
Tech Info Resource
iTrader: (2)
Have you set the fluid level? Sounds like it's a little low. These gearboxes do weird things when the oil level is even just a little bit low.
01-15-20, 01:56 PM
#37
Pole Position
Was the RCF FULLY warmed up, including the transmission fluids?
Recently I've been driving to mountain areas of SoCal where it is just below freezing in the low to mid 20's parked overnight. This happened to me too. The temperature gauges did not show "fully warmed up" until I had been driving at 65+mph for like over half an hour. Also the tachometer initially showing redline at like around 4.5K rpm and slowly increased as all the fluids warmed up slowly After that all shifting as before.
Recently I've been driving to mountain areas of SoCal where it is just below freezing in the low to mid 20's parked overnight. This happened to me too. The temperature gauges did not show "fully warmed up" until I had been driving at 65+mph for like over half an hour. Also the tachometer initially showing redline at like around 4.5K rpm and slowly increased as all the fluids warmed up slowly After that all shifting as before.
The following users liked this post:
Mingofish (01-16-20)
06-18-20, 09:57 PM
#38
Driver School Candidate
Was the RCF FULLY warmed up, including the transmission fluids?
Recently I've been driving to mountain areas of SoCal where it is just below freezing in the low to mid 20's parked overnight. This happened to me too. The temperature gauges did not show "fully warmed up" until I had been driving at 65+mph for like over half an hour. Also the tachometer initially showing redline at like around 4.5K rpm and slowly increased as all the fluids warmed up slowly After that all shifting as before.
Recently I've been driving to mountain areas of SoCal where it is just below freezing in the low to mid 20's parked overnight. This happened to me too. The temperature gauges did not show "fully warmed up" until I had been driving at 65+mph for like over half an hour. Also the tachometer initially showing redline at like around 4.5K rpm and slowly increased as all the fluids warmed up slowly After that all shifting as before.
That being said, Lexus NA did try to blame it on the transmission not being fully warm, and the shift logic in the ecu. To be honest its never caused me an issue when it mattered and I wasn't going to argue with Lexus NA for months to get a new transmission so I let it go. Its happened again since my post, and it happened before as well.
Again, this is happening when I want to up shift, not
downshift... So I'm lessening the load on the engine not increasing it.
06-19-20, 01:41 PM
#39
Tech Info Resource
iTrader: (2)
No, the car will easily go into 8th at 74 mph.
Nah I didn't check it, at the time the vehicle was under warranty so I let the dealer handle it, I assume they checked this but tbh it was a while ago, so I don't remember. I'll check this and report back. Thanks for the insight.
It was warm enough for full redline. This reasoning does not fall in line with reason you present (IMO), as I wanted to upshift and reduce RPM.
That being said, Lexus NA did try to blame it on the transmission not being fully warm, and the shift logic in the ecu. To be honest its never caused me an issue when it mattered and I wasn't going to argue with Lexus NA for months to get a new transmission so I let it go. Its happened again since my post, and it happened before as well.
Again, this is happening when I want to up shift, not
downshift... So I'm lessening the load on the engine not increasing it.
Nah I didn't check it, at the time the vehicle was under warranty so I let the dealer handle it, I assume they checked this but tbh it was a while ago, so I don't remember. I'll check this and report back. Thanks for the insight.
It was warm enough for full redline. This reasoning does not fall in line with reason you present (IMO), as I wanted to upshift and reduce RPM.
That being said, Lexus NA did try to blame it on the transmission not being fully warm, and the shift logic in the ecu. To be honest its never caused me an issue when it mattered and I wasn't going to argue with Lexus NA for months to get a new transmission so I let it go. Its happened again since my post, and it happened before as well.
Again, this is happening when I want to up shift, not
downshift... So I'm lessening the load on the engine not increasing it.
01-29-21, 08:42 PM
#40
Driver School Candidate
Well, as we know the auto tranny can have a delay and/or be jerky at certain RPMs. We know that manual mode helps with some issues. There have been a couple times before in full auto “S” mode that when I mash the gas pedal, there is big delay/hesitation (almost like complete fuel cut) before the power kicks in.
Yesterday, I was on the way home driving in Sport full auto mode. I made a right turn at a light and went full throttle. The car did the same hesitation while the gears dropped to a lower gear...but then it acted like it went into limp mode. I tried accelerating but would barely go and rpms barely went up. Tried switching to manual mode and same thing. I was NOT happy at that moment. Drove slowly back home and just parked in the garage. Decided to wait until the next morning to troubleshoot but was weighing on my mind the whole time. I don’t do well when things don’t work like they are supposed to
In my head I am analyzing the situation and going through all scenarios about what it could be. I am **** about taking care of my car and getting all required maintenance completed when it is due. I know oil is still good and so is the level. Air intake filter is good and recently cleaned at my last maintenance visit (30k miles...at 33k now). Transmission fluid was flushed/replaced at last visit which cost me extra so that is still good as well as the level. Spark and ignition should be fine. Battery and alternator should still be fine...no issues with electricity/charge that is apparent. Brakes or suspension would not cause this issue.
At this point, I am thinking fuel pumps or tranny ECU programming...then I decided I would start with the most basic and go from there: ECU reset.
This morning I went out and disconnected the battery. Pressed on the brake pedal and waited for 60 seconds. Reconnected and tried to turn on the car but it stalled. Looks like the computer needed to reinitialize. I waited until it finished and then the car started up fine. Put it in reverse, pulled out of garage, left the car there running to sufficiently warm up while I went back inside to eat bfast.
After waiting about 10 mins, I went back outside and got in. Reprogrammed the seat setting in memory. Engine temp display was showing arrow at the normal middle spot so took the cat out for a spin for analysis. Car was in full auto “S” mode and I immediately noticed it was shifting better and the RPMs were increasing like normal. Good sign. Slowly drove down the road trying to see if any volatility or erratic behavior with engine and/or transmission. Nothing. Good sign. At the end of the one road and knowing that the tranny oil was sufficiently warm, I started to increase my acceleration. Feeling good/normal. At this point, I am still hesitant to fully lay into it with the fear of the previous issue reoccurring. I decide to go for it. Acceleration is strong with no flux/hesitation. Now I can breathe a sigh of relief and thank God that it is driving normal again
I did the ECU reflash at the dealer a while ago and no noticeable change but still have the recall notification about the HPFPs. At some point, I will take it in for that and let the tech know about what recently happened with the car. Maybe at the 35k service.
Really weird what occurred and even weirder was that there was no CEL during/after it occurred. Weirder still is an ECU reset seems to have alleviated my issue.
Any thoughts or has anyone had this happen as well?
Yesterday, I was on the way home driving in Sport full auto mode. I made a right turn at a light and went full throttle. The car did the same hesitation while the gears dropped to a lower gear...but then it acted like it went into limp mode. I tried accelerating but would barely go and rpms barely went up. Tried switching to manual mode and same thing. I was NOT happy at that moment. Drove slowly back home and just parked in the garage. Decided to wait until the next morning to troubleshoot but was weighing on my mind the whole time. I don’t do well when things don’t work like they are supposed to
In my head I am analyzing the situation and going through all scenarios about what it could be. I am **** about taking care of my car and getting all required maintenance completed when it is due. I know oil is still good and so is the level. Air intake filter is good and recently cleaned at my last maintenance visit (30k miles...at 33k now). Transmission fluid was flushed/replaced at last visit which cost me extra so that is still good as well as the level. Spark and ignition should be fine. Battery and alternator should still be fine...no issues with electricity/charge that is apparent. Brakes or suspension would not cause this issue.
At this point, I am thinking fuel pumps or tranny ECU programming...then I decided I would start with the most basic and go from there: ECU reset.
This morning I went out and disconnected the battery. Pressed on the brake pedal and waited for 60 seconds. Reconnected and tried to turn on the car but it stalled. Looks like the computer needed to reinitialize. I waited until it finished and then the car started up fine. Put it in reverse, pulled out of garage, left the car there running to sufficiently warm up while I went back inside to eat bfast.
After waiting about 10 mins, I went back outside and got in. Reprogrammed the seat setting in memory. Engine temp display was showing arrow at the normal middle spot so took the cat out for a spin for analysis. Car was in full auto “S” mode and I immediately noticed it was shifting better and the RPMs were increasing like normal. Good sign. Slowly drove down the road trying to see if any volatility or erratic behavior with engine and/or transmission. Nothing. Good sign. At the end of the one road and knowing that the tranny oil was sufficiently warm, I started to increase my acceleration. Feeling good/normal. At this point, I am still hesitant to fully lay into it with the fear of the previous issue reoccurring. I decide to go for it. Acceleration is strong with no flux/hesitation. Now I can breathe a sigh of relief and thank God that it is driving normal again
I did the ECU reflash at the dealer a while ago and no noticeable change but still have the recall notification about the HPFPs. At some point, I will take it in for that and let the tech know about what recently happened with the car. Maybe at the 35k service.
Really weird what occurred and even weirder was that there was no CEL during/after it occurred. Weirder still is an ECU reset seems to have alleviated my issue.
Any thoughts or has anyone had this happen as well?
Dragging this one back to life. I had a similar issue but cleaned my air intake sensor (after the air box) with pure isopropyl alcohol and it did the trick
Thread
Thread Starter
Forum
Replies
Last Post