6 Speed Auto Modes (D4, D5 etc)

jimmyrand · July 23, 2017

So I thought I would try the Auto modes where you can stop it going higher than a certain gear. I fully understand the idea, I normally use this features on twisty roads to stop the gearbox from constantly going up and down. I selected D5, the display changed as expected. I got the impression the car down shifted, then after around 3 seconds the display changed back to D (no D5), I pressed the - paddle again and it showed D5. then back to D. I then tried moving down to D4, the same thing happened, display changed back to D. When I pressed the - paddle again it showed D4 (not D5) so it had remembered that I had selected D4.

I was expecting the display to show D4, D5 etc until I held the + paddle to switch back to normal Drive. Am i doing something wrong, does the display show D when D4 is selected?

NemesisUK · July 23, 2017

Any of these criteria apply? (from the owner's handbook

Automatic deactivation of shift range selection in the D position
Shift range selection in the D position will be deactivated in the following situations:
● When the vehicle comes to a stop
● If the accelerator pedal is depressed for more than a certain period of time
●When the shift lever is shifted to a position other than D

I imagine you accelerated for more than the accepted period of time?

jimmyrand · July 23, 2017

12 minutes ago, NemesisUK said:

Any of these criteria apply? (from the owner's handbook

Automatic deactivation of shift range selection in the D position
Shift range selection in the D position will be deactivated in the following situations:
● When the vehicle comes to a stop
● If the accelerator pedal is depressed for more than a certain period of time
●When the shift lever is shifted to a position other than D

I imagine you accelerated for more than the accepted period of time?

Thanks for the reply

I was maintaining 23 to 35 MPH, so the accelerator was slightly open at the time I selected D4/D5. Do I need to take my foot off the accelerator, select D5 or D4 etc, then apply the accelerator? This would seem to imply that it is only intended to slowing down?

It changed from D4 or D5 back to D after around 3 seconds of use, the period of time cant be 3 seconds? I would have thought a few minutes?

I might need to try this again tomorrow. The car drives fine, manual modes works well as expected. Car has only 4000 which is nice and low for a 2014 car. I might not have been going fast enough for those gears?

NemesisUK · July 23, 2017

The manual does state that when using shift ranges in D it only really used for deccelerating (engine braking), try it when in S and see if it stays longer. The manual states when in Sport mode one can use shift ranges for increased accelerating force..

jimmyrand · July 23, 2017

10 minutes ago, NemesisUK said:

The manual does state that when using shift ranges in D it only really used for deccelerating (engine braking), try it when in S and see if it stays longer. The manual states when in Sport mode one can use shift ranges for increased accelerating force..

Thanks I will give it a go.

The manual also says "preventing unnecessary up shifting". Remembering my old Rover 620 (on my IS300 I used D or manual only), it had D and D3. D3 would not allow the car to go into overdrive (4th top gear), you could use it to drive up a steep hill or going down one, also good for twisty roads.

The car is going into MK Lexus for the wheel arch recall on Wednesday and under guarantee with Arnold Clark so I'll have a go and see what Lexus say.

PaulWhitt20 · July 23, 2017

Mine does the same. I don't use the flappy paddles. They are a bit daft on a CVT anyway where there are no gears. I suspect they are only there to keep up with the Germans so you can say it's got flappy paddles.

May be useful to downshift for an overtake but in normal driving just let the car do its thing and enjoy the ride.

J Henderson · July 23, 2017

I believe it'll always revert to "D" mode after a while unless you switch the gearbox into "S" mode.

Linas.P · July 23, 2017

4 minutes ago, PaulWhitt20 said:

Mine does the same. I don't use the flappy paddles. They are a bit daft on a CVT anyway where there are no gears. I suspect they are only there to keep up with the Germans so you can say it's got flappy paddles.

May be useful to downshift for an overtake but in normal driving just let the car do its thing and enjoy the ride.

That is not really true for both statements:

1. @jimmyrand has IS250 mk3, which has same engine and gear box as IS250 mk2, it is 6 speed Auto and not CVT . The problem Mike has is that he tries to change gears whilst in D-mode. When in D-mode mk3 IS250 and mk2 IS250 after 2009 allows you to temporary downshift e.g. before overtaking and then returns back to D. If you want the car to stay in selected gear then you need to go into S-mode with your gear leaver and it will keep you in the same gear. That is... unless you go beyond RPM limiter, then it will automatically change the gear-up even in S-Mode to prevent damage.

2. As many know by now I am not big fan of 300h, but if anything it does have brilliant e-CVT box fitted in RC/IS mk3. It gives almost instant up/down shift and in my opinion is the only thing which gives the car some life. I guess your point of the being "daft" is because CVT is actually more efficient if you leave it alone - completely true, but if you have nostalgia for "manual" gear changes it does surprisingly good job and give almost "mechanical" feeling to it (much better than 6 speed auto in IS250).

jimmyrand · July 24, 2017

20 hours ago, NemesisUK said:

The manual does state that when using shift ranges in D it only really used for deccelerating (engine braking), try it when in S and see if it stays longer. The manual states when in Sport mode one can use shift ranges for increased accelerating force..

You're right. It works as you said, it's only for engine breaking. The handbook isn't clear and misleading when it mentions to avoid unnecessary upshifting. Might be useful going down a steep hill to save the brakes.....

Vince Donald · July 26, 2017

On 24/07/2017 at 5:37 PM, jimmyrand said:

You're right. It works as you said, it's only for engine breaking. The handbook isn't clear and misleading when it mentions to avoid unnecessary upshifting. Might be useful going down a steep hill to save the brakes.....

It is useful, a few weeks back I took my son into the peak district for his Duke Of Edinburgh walk.
As I was descending into Hathersage, it is quite a steep hill, and its 30mph, so I 'dropped it down' a couple of gears, as one wasn't enough and it held it at 30mph all the way down.

I may get to try this again soon as a visit to Scotland is on the horizon.

Vince

bluenose1940 · July 26, 2017

31 minutes ago, Vince Donald said:

It is useful, a few weeks back I took my son into the peak district for his Duke Of Edinburgh walk.
As I was descending into Hathersage, it is quite a steep hill, and its 30mph, so I 'dropped it down' a couple of gears, as one wasn't enough and it held it at 30mph all the way down.

I may get to try this again soon as a visit to Scotland is on the horizon.

Vince

I use mine (paddles rather than the brakes) all of the time to keep my speed down to within the required limit, works faultlessly. Having said that, I do touch the brakes if necessary to make sure that anyone that is too close up my backside is aware that I am slowing down. If they are too close and don't see any brake lights they could well end up clouting me.

NemesisUK · July 26, 2017

12 minutes ago, bluenose1940 said:

I use mine (paddles rather than the brakes) all of the time to keep my speed down to within the required limit, works faultlessly. Having said that, I do touch the brakes if necessary to make sure that anyone that is too close up my backside is aware that I am slowing down. If they are too close and don't see any brake lights they could well end up clouting me.

Surely you're losing one advantage of having a hybrid, regenerative braking? By 'touching' the brakes, one isn't actually using the pads and discs but the electric motors acting as generators, slowing the car and recharging the Battery.

jimmyrand · July 26, 2017

1 hour ago, Vince Donald said:

It is useful, a few weeks back I took my son into the peak district for his Duke Of Edinburgh walk.
As I was descending into Hathersage, it is quite a steep hill, and its 30mph, so I 'dropped it down' a couple of gears, as one wasn't enough and it held it at 30mph all the way down.

I may get to try this again soon as a visit to Scotland is on the horizon.

Vince

That's a good idea and I'm glad I discovered it. I will probably use it when I'm on holiday. East midlands is fairly flat so I will keep it in D most of the time. It's good that it cancels again by itself.

I thought it might have also given a low gear when climbing a similar hill. Maybe it's not such a problem now autos have 6 gears. In previous Hondas or Hovers (Honda Rovers) D3 would also provide extra control preventing the box from repeatedly going up and down through the gears when climbing a steep hill as if it couldn't make up its mind. Then switch back to D for normal driving with overdrive. The Lexus handbook could be clearer, it does mention to prevent unnecessary up shifts, how many upshifts to you have when braking? It's almost as if they hadn't finalised the feature when the book was written as it also mentions 'a certain amount of time'...

It's not a problem now I know how it works, it's easy enough to select Manual mode when I feel the need for greater control or overtaking. I'm impressed with the ride and how smooth the transmission is.

Vince Donald · July 27, 2017

On 7/26/2017 at 2:39 PM, NemesisUK said:

Surely you're losing one advantage of having a hybrid, regenerative braking? By 'touching' the brakes, one isn't actually using the pads and discs but the electric motors acting as generators, slowing the car and recharging the battery.

Yeah, but by using the paddles, you will see that the car goes into regen too. I did see somewhere, it may even have been on this forum that once the Battery is full and can't take any more, the car will spin the engine to have actual engine braking, but that would be a pretty big hill, maybe something like the Applecross road in Scotland, but I'm pretty sure I'd be using my brakes on that one.

Vince

NemesisUK · July 28, 2017

11 hours ago, Vince Donald said:

Yeah, but by using the paddles, you will see that the car goes into regen too. I did see somewhere, it may even have been on this forum that once the battery is full and can't take any more, the car will spin the engine to have actual engine braking, but that would be a pretty big hill, maybe something like the Applecross road in Scotland, but I'm pretty sure I'd be using my brakes on that one.

Vince

Just tried this on the long hill down to my home. Yes, when using the paddles to invoke engine braking the energy meter goes into regen but only briefly, as if the car is slowing to match road speed to engine revs, which then rise and the regen diminishes to that which one sees when simply coasting on the flat.

Using the brakes to slow down the descent produces a much larger and constant deflection in to the regen zone.