Can Anyone Explain How And When To Use The B On The Shift Lever?

[HelenT]

Hi, Got my Prius a couple of months ago I've worked out and tried most things except the B on the shift lever. There's very little about it in the manual that I can find. I asked a colleague who has a Prius and he said he didn't know, never used it. Can anyone explain please?

[Cyker]

It's basically engine braking; The only time you'd use it is during long downhill descents where the traction Battery is full and not providing any regen braking, and you don't want to fry the friction brakes.

That long twisty scary hill descent near Bath is a good example of a place you'd like to use B! :)

[cootuk]

I also use it to keep to the speed limit down steep hills, quite heavy engine braking with it.

Find a steep hill and try it...

[ToyotaAurisHybrid]

We have some steep downhill 30mph zones around us and it works well for me on these, keeping me at the limit

[Dasbob]

Have a nice 1 in 4 hill near me and it really does make a difference.... same thing you can do with a manual gear box and if you ever driven a land rover down a muddy slope you will know that using the BRAKE and not engine BRAKING means free falling.

I went on a "Land rover experience" day with work and we all got to drive land rovers around steep muddy hills, the instructor informed us that every corner at the bottom of a hill is named after an instructor, when we asked why, he said that when going down the steep slopes some people panic and instant reflex reaction is to slam the BRAKE on... which means you hurtle down the slope.... so a few instructors have had close calls on these corners.... i dont know the mechanics of it, but i suspect its because the wheels lock up and you slide down, but having the engine slowing you down causes the vehicles wheels to keep gripped

although don't panic, this only applies to steep muddy slopes which your car would never manage any way! ... so long and short is to stick it in B and BRAKE, just means when you take foot off BRAKE you wont beat the land speed record and will accelerate at a more manageable pace

[timberwolf]

Brake Fade. Isn't this basic knowledge that every driver should know already?

[HelenT]

Thanks guys, I'll give it a go. Having never driven an automatic before I was a bit wary of touching the gears while the car is moving.

[Aceshigh84]

I don't think the car will let you select the wrong "gear" if it's moving - I haven't actually tried selecting reverse when going forward, but I did once press the park button at 40 and B*tching Betty moaned like crazy.

[Dasbob]

I did manage to put it into reverse when almost being at a stand still... i also managed to slow down going up a hill to the point of stop (without touching BRAKE) and the car kept its position (slight roll back)... felt like the car was stationary but then the traffic ahead started moving again.

Also you will be hard pressed to stall an automatic... first time i driven an automatic in my 12 years of driving and i quite like it.

Edited August 18, 2013 by Red Yaris 54
It's BRAKE not BREAK

[HelenT]

I don't think the car will let you select the wrong "gear" if it's moving - I haven't actually tried selecting reverse when going forward, but I did once press the park button at 40 and B*tching Betty moaned like crazy.

What did you do after you pressed the park button by mistake?? I've been worried about doing the same myself while I've been getting used to where everything is.

It also doesn't help that the reverse is forward and drive backward, doesn't seem logical to me. Love driving the Prius, just takes a while to get used to everything and it doesn't help when I keep switching to a manual car when transporting my dogs.

[Aceshigh84]

What did you do after you pressed the park button by mistake?? I've been worried about doing the same myself while I've been getting used to where everything is.

I did what any other self respecting male would do in those circumstances - I blamed the car & shouted various expletives at it until the bleeping stopped.

As for the position of the direction shift, I personally don't see a problem with it. There have been quite a few posts on here with people saying it is wrong etc, but I don't see it is any different to a normal manual gearbox - with a Ford you push the stick forward to select reverse, and on every gearbox you pull back for 2nd, 4th & 6th.

When at a junction in neutral with the handbrake on (&/or park) I personally find it more intuitive to just flick my wrist back to go, but that is just me :-)

[Dasbob]

What did you do after you pressed the park button by mistake?? I've been worried about doing the same myself while I've been getting used to where everything is.

I did what any other self respecting male would do in those circumstances - I blamed the car & shouted various expletives at it until the bleeping stopped.

love it! haha. I did the same thing when i first drove it and didn't manage to close the boot correctly

I personally don't use the park feature unless am parking or stuck in traffic for a long period of time, i find just resting my foot on the brake is sufficient. It is quite far out the way of the gear changing knob thing so i wouldn't worry about hitting it. It is one of those buttons that is the same level as the casing it sits in, so to activate it you would have to push it down.

It is confusing at first with reverse and drive... reversed! but i promise after a few weeks you wont even notice. I drove my old peugeot (manual) to be sold and stalled it 3 times and ground the gears on the way as i had gotten so use to the Hybrid

[timberwolf]

Toyota are pretty much just following the convention set by regular cars with automatic gear selectors (Front) P - R - N - D - 3 - 2 - 1 (Back).

AIUI the reason for keeping to the convention is it will be familiar to anyone already used to an automatic transmission. Not a problem for most people living in North America where manual transmissions are less common. but more of a problem else where in the world.

[johalareewi]

Toyota are pretty much just following the convention set by regular cars with automatic gear selectors (Front) P - R - N - D - 3 - 2 - 1 (Back).

P-R-N-D is a requirement in the USA. Hence the 'strange' arrangement with the Prius and the P button.

[Opifex]

Brake Fade. Isn't this basic knowledge that every driver should know already?

This is less likely in a Prius than a normal car since a lot of the braking, even on a steepish hill, is done by the regenerative system.

I don't think the car will let you select the wrong "gear" if it's moving - I haven't actually tried selecting reverse when going forward, but I did once press the park button at 40 and B*tching Betty moaned like crazy.

What did you do after you pressed the park button by mistake?? I've been worried about doing the same myself while I've been getting used to where everything is.

It also doesn't help that the reverse is forward and drive backward, doesn't seem logical to me. Love driving the Prius, just takes a while to get used to everything and it doesn't help when I keep switching to a manual car when transporting my dogs.

I did once hit the P button before the car was at a total stop and the effect was that we came to a very abrupt halt. I haven't tried it, but I believe that the button is disabled if you are doing anything more than a crawl.

I personally don't use the park feature unless am parking or stuck in traffic for a long period of time........

You're probably correct, but I was told by the salesman when I bought the car that you can always use the P button and never need to use the foot-operated brake.

Toyota are pretty much just following the convention set by regular cars with automatic gear selectors (Front) P - R - N - D - 3 - 2 - 1 (Back).

P-R-N-D is a requirement in the USA. Hence the 'strange' arrangement with the Prius and the P button.

I've no problem with the R-N-D bit but why was the P moved to a separate button instead of being on the shift lever?

[timberwolf]

Brake Fade. Isn't this basic knowledge that every driver should know already?

This is less likely in a Prius than a normal car since a lot of the braking, even on a steepish hill, is done by the regenerative system.

My question was general, as I understand it a driving license typically permits a driver to drive many makes of car and to my knowledge most of them do not have regenerative braking systems.

The friction brakes on a Hybrid typically have thinner pads and discs than conventional cars, would they heat up more quickly once the brake system had to switch to full friction braking (e.g. when the HV Battery is full)? How about riding the brakes down a long mountain road for x miles, what distance could you rely on it to be regenerative braking?

[johalareewi]

The friction brakes on a Hybrid typically have thinner pads and discs than conventional cars, would they heat up more quickly once the brake system had to switch to full friction braking (e.g. when the HV battery is full)? How about riding the brakes down a long mountain road for x miles, what distance could you rely on it to be regenerative braking?

When the HV Battery fills up and regenerative braking is no longer available, Toyota hybrids will automatically engage engine braking to help the friction brakes.

[johalareewi]

I've no problem with the R-N-D bit but why was the P moved to a separate button instead of being on the shift lever?

Not sure how you could put P on the Prius gear stick to give you P-R-N-D. It's not like an mechanical auto gearbox. It's more of a joystick.

[Opifex]

I've no problem with the R-N-D bit but why was the P moved to a separate button instead of being on the shift lever?

Not sure how you could put P on the Prius gear stick to give you P-R-N-D. It's not like an mechanical auto gearbox. It's more of a joystick.

They've managed it on the Yaris Hybrid.

[Cyker]

On the Yaris HSD it's set up more like a conventional linear autobox selector whereas in the Prius and Auris it's styled as a pseudo-manual gearshift.

The Prius way is faster as you just move the stick to what you want it to do but confused some people which is why I think they went back to a more conventional layout in the Yaris HSD where you have to go through other selectors to get to what you want.

(Personally, if someone could remain confused by the gear shift I wouldn't let them drive a car! )

[Yolina]

(Personally, if someone could remain confused by the gear shift I wouldn't let them drive a car! )

Indeed.

And I know that nowadays even the obvious needs to be stated otherwise someone might sue, but I do love the rather extensive info peppered all over the handbook and some is really like:

"drive carefully when it is raining because visibility will be reduced, the windows may become fogged-up, and the road will be slippery"

"Do not drive if you are unfamiliar with the location of the brake and accelerator pedals to avoid depressing the wrong pedal."

No wonder the handbook is so large...

You'd almost think it's aimed at 5-year olds

[timberwolf]

I always enjoyed reading the Owner's Manual when I was a boy although probably not as young as five - I liked the exploded diagrams with numbered/lettered keys and I always wanted to know how things worked.

[Grannie]

I live in a very hilly area and use "B" every time I descend a hill. However, no one has been able to tell me exactly how it works. I'm used to manual transmissions which I used when going up and down hills -- simply shift into a lower gear. If both the "Power" button and the "B" button work through engine "downshifting," then what's the difference between the two of them?

[geo13647]

The 'B' button is the hybrid equivalent of downshifting on a manual trans,

Most pure auto trans (i.e. torque converter) have no equivalent and rely on beefy friction brakes only.

my understanding is that it uses the engine compression to act as a retarder to the drive train,

Giving the same/ similar effect that a Heel brake retarder works on an artic.

I use mine just as I would downshift in a manual trans to scrub off speed on a steep descent or a fast corner.

The 'Pwr' button is a whole different ball of wax, it remaps the throttle & control ECU's to give a more lively response to driver input, it also uses MG2 & the ICE in combination to give a bit more oomph.

Well that's my understanding anyways.

G...

[johalareewi]

I live in a very hilly area and use "B" every time I descend a hill. However, no one has been able to tell me exactly how it works.

There are 3 ways of braking with a toyota hybrid. Regenerative braking where a generator charges up the HV Battery, engine braking where the petrol engine is spun like an air compressor, and good old friction brakes. Nornally, regenerative braking is used but when the HV Battery is full or will not provide enough braking power, the other methods are called up (this is done automatically). Putting the car in B mode switches engine braking on permanently. It is usefull on long steep descents where you don't want the car to 'run away'.

I'm used to manual transmissions which I used when going up and down hills -- simply shift into a lower gear. If both the "Power" button and the "B" button work through engine "downshifting," then what's the difference between the two of them?

The PWR button makes the accelerator pedal more responsive. There is no engine downshifting with a toyota hybrid.

More info here...

http://en.wikipedia.org/wiki/Hybrid_Synergy_Drive