Caught out by strange seatbelt interlock and parking brake

[Nick72]

Caught out by this logic which 'may' make sense for some situations but not others. Anyone else had this or know of any other seatbelt related moding of other interlocking?

I'm in very slow stop start traffic trying to exit the M25 and I'm on the slip road. Hate that motorway. I enable the brake hold mode to give my foot a rest in the the stop start situation. So I'm stopped at this point and brake auto hold is on. My throat is dry and sore (medical issues). But my water bottle is in the passenger door well. I unlock my seat belt and reach over to get the bottle and have a swig. The traffic starts moving so I attempt to drive off as I'm in the process of putting my seatbelt back on. Big clunk like driving an old car when you left the handbrake on. I'm not moving. Warning message on the driver display that I didn't have time to comprehend. Put seatbelt in and still another big clunk. I'm going nowhere. Cars beeping behind me at this point. Then I notice the parking brake has been automatically enabled and lit up red so I then undo the parking brake (which I never use because I've set It to automatically come on or off with the shifter position of P or D) so I can finally drive off.

So it seems when I undid the seatbelt when auto hold is on, the car switched off auto hold and engaged the parking brake proper and issued a warning which was too long to read and comprehend.

Anyone understand the logic here? I mean if I opened the car door I could understand the car taking it out of auto hold mode and engaging the parking brake permanently but why do it on the seatbelt? I'm stationary or very slow moving! 

No bother in the grand scheme of things but did catch me out. Now wondering what other interlocks or moding there is?

 

 

[Kos_ta]

Not just Toyota thing. Merc Sprinter at work does this as well in exact same fashion - seat belt undone - parking brake on applied automatically. 

[Mjolinor]

So can you set off from a fresh start without the seat belt on?

 

[philip42h]

1 hour ago, Nick72 said:

I enable the brake hold mode to give my foot a rest ...

I would never have that problem - I never use brake hold. In precisely your situation I would have stuck the car into Park, taken off seat belt etc. etc. When I needed to pull away again, I'd stick it back into Drive and go - if I had the seat belt on, fine; if I didn't, the bleeper would complain, increasingly urgently until I did, but I'd still be 'gone' ...

[Nick72]

1 hour ago, Mjolinor said:

So can you set off from a fresh start without the seat belt on?

 

Yes.

[Cyker]

4 hours ago, Nick72 said:

Caught out by this logic which 'may' make sense for some situations but not others. Anyone else had this or know of any other seatbelt related moding of other interlocking?

I'm in very slow stop start traffic trying to exit the M25 and I'm on the slip road. Hate that motorway. I enable the brake hold mode to give my foot a rest in the the stop start situation. So I'm stopped at this point and brake auto hold is on. My throat is dry and sore (medical issues). But my water bottle is in the passenger door well. I unlock my seat belt and reach over to get the bottle and have a swig. The traffic starts moving so I attempt to drive off as I'm in the process of putting my seatbelt back on. Big clunk like driving an old car when you left the handbrake on. I'm not moving. Warning message on the driver display that I didn't have time to comprehend. Put seatbelt in and still another big clunk. I'm going nowhere. Cars beeping behind me at this point. Then I notice the parking brake has been automatically enabled and lit up red so I then undo the parking brake (which I never use because I've set It to automatically come on or off with the shifter position of P or D) so I can finally drive off.

So it seems when I undid the seatbelt when auto hold is on, the car switched off auto hold and engaged the parking brake proper and issued a warning which was too long to read and comprehend.

Anyone understand the logic here? I mean if I opened the car door I could understand the car taking it out of auto hold mode and engaging the parking brake permanently but why do it on the seatbelt? I'm stationary or very slow moving! 

No bother in the grand scheme of things but did catch me out. Now wondering what other interlocks or moding there is?

 

My Yaris also behaves like this so it's not just yours!

I'd be a good idea to get into the habit of going into P when doing things like that, as P is 'fail-safe', while the brake-hold is *not* fail-safe, which is why it behaves like this.

The Brake Hold has several conditions that must be met for it to work, and one of those is the seat belt has to be on. If any of the conditions are not met it will automatically transfer to the EPB with that horrible lurch.

 

It may help to think of it this way - Brake Hold is like a virtual foot on the foot brake, so use it in any situation that you'd otherwise hold down the foot brake yourself.

However, e.g. if you were going to get out of the car or turn around to try and pick something off the back seat, it's better to go to EPB/Park for the same reason why you'd not try and hold on the footbrake normally while doing such things.

 

[Nick72]

5 hours ago, Cyker said:

My Yaris also behaves like this so it's not just yours!

I'd be a good idea to get into the habit of going into P when doing things like that, as P is 'fail-safe', while the brake-hold is *not* fail-safe, which is why it behaves like this.

The Brake Hold has several conditions that must be met for it to work, and one of those is the seat belt has to be on. If any of the conditions are not met it will automatically transfer to the EPB with that horrible lurch.

 

It may help to think of it this way - Brake Hold is like a virtual foot on the foot brake, so use it in any situation that you'd otherwise hold down the foot brake yourself.

However, e.g. if you were going to get out of the car or turn around to try and pick something off the back seat, it's better to go to EPB/Park for the same reason why you'd not try and hold on the footbrake normally while doing such things.

 

Good advice, thank you. Now I know that the convenience can't be used in the way I did I'll put it into park before d'ing around. 😅