Hybrid Gear Slection

[Mick F]

You can't start without the gear selector in P and your foot on the footbrake.  You can't switch off without being in P with your foot on the footbrake.

However .............................

When driving in D, there's nothing to stop you selecting P or R whilst moving even though you don't depress the footbrake. ..................  I've experimented .................. at very slow speed of course to prove this.

Why is this allowed?  What happens if you select P or R when driving along at speed?   

Is our Hybrid gear selector system defective?

Mick.

[Anthony Poli]

You can't start without the gear selector in P and your foot on the footbrake.  You can't switch off without being in P with your foot on the footbrake.
However .............................
When driving in D, there's nothing to stop you selecting P or R whilst moving even though you don't depress the footbrake. ..................  I've experimented .................. at very slow speed of course to prove this.
Why is this allowed?  What happens if you select P or R when driving along at speed?   
Is our Hybrid gear selector system defective?
Mick.

Can’t say I have tried in ours, but from what I gather from others, you might be able to select the different gears/mode but the computer won’t let you do anything really dangerous.
With my Auris if you are just creeping and you press P it will stop, others have joked that P stood for panic and it would behave like it was in neutral. Since the gear stick is only operating switches, it should only let you do what the computers think is correct.


Sent from my iPad using Tapatalk

[Mike J.]

I was going to write about the D to R process. I can move from D to R and back again whilst moving slowly. Going by the transmission design, I can't see this as a problem as the gearbox is epicyclic and all the gears are always meshed. What (I believe) should not be done is select P whilst moving, as it uses a pawl and you could snap it off!

Check out this bit of video to show the interactions of MG1, MG2 and the petrol engine:

https://youtu.be/WL9I_MLj1aw?t=391

Although the video is of the Prius, you can see that the petrol engine only interacts with the final drive if and when the MG1 allows it.

[Mick F]

Thanks guys!

Very interesting stuff.

D/R seems as if it's a normal thing, but I can't understand why the system allows you to select P without being stationary and with your foot on the brake.  If you can do it and this was to cause damage, why do they allow you to do it at all?

Mick.

[Bomber209]

Hi All; The way I understand it, although you can select R & P there is no effect until you press the foot brake and actually stop. The 'P' locking pawl drops in when vehicle has stopped. As 

stated the epicyclic gear doesn't care if it's going one way or the other, it's the directional power for the electric motor that reverses polarity to give you opposite direction drive.

[Mick F]

27 minutes ago, Bomber209 said:

Hi All; The way I understand it, although you can select R & P there is no effect until you press the foot brake and actually stop. The 'P' locking pawl drops in when vehicle has stopped. As 

stated the epicyclic gear doesn't care if it's going one way or the other, it's the directional power for the electric motor that reverses polarity to give you opposite direction drive.

Not true with ours.

When we first bought the car, I inadvertently moved the gear lever into "1st gear" to get up the drive.  Obviously, I was very used to manual cars and without thinking, I selected 1st as usual ...................... except we were in a Yaris Hybrid.  The car was moving at circa two or three miles per hour, and when I selected 1st ........... Park! .......... the car stopped suddenly and fiercely.

Also, in a carpark when it was quiet, I moved forward in Drive without depressing the accelerator pedal, then without stopping or touching the brake, moved the selector to Reverse.  The car instantly went backwards.

Mick.

[Mike J.]

3 hours ago, Mick F said:

.... and when I selected 1st ........... Park! .......... the car stopped suddenly and fiercely.

That would be the pawl stopping the transmission - not nice.

[YarisHybrid2016]

I would never try selecting P at any speed, just in case (knowing my luck, it would break).

It let me select N from D at 4 MPH this evening when I was investigating a brake problem. I dare not try any faster as I'm unsure if it can do any damage (the HV Battery is supposed to be disconnected, so there is nowhere for the electrical energy from MG2 to go - unless it spins the engine via MG1? Hmm...).

You can switch the car off at any time. I have accidentally switched it off in D before now (handbrake on). What it won't do is let you switch it ON without being in P and with your foot on the brake.

There are a few other safety systems, too - if you brake and accelerate at the same time, it removes the drive as it thinks the accelerator got stuck and you're trying to stop.

You can't rev the engine with it parked - if you hold your foot on the floor in P, it will run up to what I think is the MOT test RPM, but no faster, and it accelerates the engine slowly to get there (don't try this with a cold engine, though I think there is a protection for that, too).

Hybrids are pretty indestructible.

[Mick F]

Yes, I imagine they would be pretty indestructible, but why do the allow you to (possibly) destroy it by inadvertently selecting P when the car is moving?

No real experience of an automatic gearbox.  Can you select P in a normal automatic when moving?

Mick.

[Bomber209]

Hi, On some models of automatic you can select from Reverse to Park while still moving, and it jams the pawl in, going from Drive to Park you would have to go through Reverse, and if you're still moving you cannot pass beyond Neutral. In a regular auto you'd tear the gearbox apart if you managed it. There is usually a lock solenoid that gets a signal via the speedo.