Yes. Go to settings - Driving Assist- Driver support - scroll down to Deceleration assist. To turn it on or off.
Downshift when approaching stops
- Thread starter Trac1
- Start date
This is a setting that’s under the Proactive Driving Assist. So it only applies when Proactive Driving Assist is on. And it definitely isn’t going to change the transmission’s operation.
Hmm. Seems like it worked for me but I see what you mean. I’ll try it again.
I already had this setting in the OFF position. It's pretty aggressive at braking you in traffic or at stop lights.
Think that is a different situation than what was noted. Transmission slows down with down shifts to maintain speed (not accelerate due to gravity or previously generated momentum). The proactive assist is mostly when approaching other vehicles. Some on the turns as well, but not when just coasting down hill.
Interesting. So does approaching a light with a vehicle in front of you count as proactive assist? Sure seems like the braking gets more aggressive to me.
I found that the truck was very aggressively braking itself when I was coming to a stop at stop signs or traffic lights. Like you're the little old lady who has to ride the brakes to stay 100 feet away from the car in front of you in slow-moving traffic. Very annoying and distracting so that feature got turned off right away. The automatic cruise control is equally annoying with aggressive braking if a car pulls into your highway lane waaaay ahead of you (and I have the adjustable distance setting at the closest setting). What ends up happening is that people behind you see you leaving a giant gap ahead of you and they just pass you on the right and you keep moving back in the rotation.
I also turned off the driving assist half way through our test drive in traffic. Not knowing how it worked, it created a jerky stop and go. We almost didn't like the truck because of that. Once the salesman turned it off (my wife was driving) it was night and day. After reading the manual and later trying it out again I found it can be helpful and less fatigue driving in limited traffic and stop and go areas. You can drive, coast and vehicle will do some braking if that is not enough without lifting the right foot to the brake. It does not complete the stop if coming to a light and a car is in front of you. You do need to intervene to stop eventually. On the highway with adaptive cruise, if a car pulls in front of you and is traveling slightly faster than you the braking is not applied.
The driving assist braking characteristic is similar but wholly separate issue than the transmission 2 to 1 clunk.
The 2-1 clunk comes on during when braking and the transmission decides to shift from 2-1 when almost at a stop. it's almost like you are in a manual transmission car and you don't know how to shift the gears. lol
The 2-1 clunk comes on during when braking and the transmission decides to shift from 2-1 when almost at a stop. it's almost like you are in a manual transmission car and you don't know how to shift the gears. lol
Hi munkeeboi, you may have already seen the other post about this. My issue was exactly that, the second to first gear shift when almost or at a stop.
www.lexusgxforum.com
Transmission down shift clunk, FIXED
In a previous post, I described a harsh downshift clunk when slowly coming to a stop. Most noticeable in stop and go traffic. Sometimes felt like two bumps, one around 3-5 mph, and the second just when I come to a full stop. I was not sure if this normal for that type of transmission or if...
www.lexusgxforum.com
Yup... the easy temp fix is disconnecting the battery for 20-30 min. 500 miles after reset and it's still good.
I have a jeep and it almost does it every time. The feeling is when the car shifts from 2nd gear to 1st gear. Instead of it being smooth, it feels like you're going into low range. (Going into low range feels more aggressive on a jeep). I had the issue in the GX when I changed to comfort mode. Comfort would always do the harsh gear change when stopping. Once i change it to Normal it went away. Its definitely toyotas mapping. I am at 10k miles on 35 inch tires.
Messaged my dealer about it, their response: "...The ECU on some of the units are requiring a technology update. It’s a communication delay in the software system on some of the GX models. It’s a simple remedy, but the issues you are indicating are exactly what the symptoms are. Let me know when you want to stop in and have us address that. Of course it is warranty work."
Resetting the adaptive transmission tables/transmission learning is simple on some vehicles, difficult on others. I reached out to Carista to see if they could add this to their device as a one-click function.
Joining in. My GX's downshifts are really bad coming to a stop, might try the battery trick.
Update: Disconnected - terminal for 5min, reconnected. Drove it for a few days and it fixed my hard downshift when coming to a complete stop. I still feel the other downshifts like its engine braking but no more jolting when coming to a stop.
Update: Disconnected - terminal for 5min, reconnected. Drove it for a few days and it fixed my hard downshift when coming to a complete stop. I still feel the other downshifts like its engine braking but no more jolting when coming to a stop.
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I’ve been dealing with this issue. Jerky downshifts when rolling to a stop. For me this started at around 6000 miles on my 24 OT+. Dealer reset ECU but the issue returned within days. Went in today to get the brake replacement. They told me the jerky downshift issue is well known and Lexus is working on a software update to remedy. According to my service guy the update should be rolled out in the next 30 days.
Let’s hope this is a permanent fix because it’s ruining my customer experience.
Let’s hope this is a permanent fix because it’s ruining my customer experience.
Thanks for the note they may be coming up with a SW fix down the road. Will keep my eyes out.
If there is future software update, I wonder if this occurs remotely or if it will require a visit to the dealership. A friend with a new Tundra told me he had his truck into the toyota dealership (no shifting issues)for routine service maintenance and they "reflashed" his transmission software due to an update.
GX550 Forum Photos
GX550 Forum Photos
