Problem closing boot door

[ernieb]

Today we parked on a downward slope and on our return opened the boot door. No issues with that but the door refused to close whatever I did. Tried both the door button and the key and until I grabbed the handle and gave it a pull and then the closure motor engaged and it closed.

I’ve assumed that because the car was on a steep downward slope it had engaged some safely system until I got it going. Any thoughts?

[Hybrid21]

I've not tried that Ernie, will try it first chance I get 👍

[Lawnmowerman]

Very odd - haven't heard of that issue reported on the forum.

[ernieb]

It’s not been an issue for me over the time I’ve had the car. However, the hill is pretty steep and the car facing downhill so just wondered if that was the cause. If you were vertically challenged you might be stuck trying to reach the handle to start the closing process by grabbing the handle?

[nlee]

I had the tailgate stick open once but it sounds slightly different to your situation. I tried to lower it manually but it didn't start the motor lowering at all and I couldn't even lock the car (because it knew the boot was open)

I can't exactly remember what I did to resolve it but I think it I had to put the car in ready, turn off, then it worked again. Only happened once so presume it was a glitch in the matrix.

Edit: it was on the drive at the time which is more or less flat.

Edited October 28, 2022 by nlee
Added further info.

[ernieb]

Sounds a bit strange and at the time really frustrating, especially as in my case it was pouring with rain and prises for guessing which direction the rain was hitting the car?

[Hayzee]

Ernie 

As it was in a steep decline maybe , as you suspect, it allowed the tailgate to extend a little further than normal, and caused a problem with a sensor perhaps?

 

 

[philip42h]

12 minutes ago, Hayzee said:

Ernie 

As it was in a steep decline maybe , as you suspect, it allowed the tailgate to extend a little further than normal, and caused a problem with a sensor perhaps?

If it were a gravity / angle issue then one might expect it not to have opened quite as fully as normal. Of course if it did that and Ernie subconsciously, or the wind, pushed it open further than 'normal' it might need encouraging back down again. Just surmising ...

In the ten years that I've had a RAV4 with a powered tailgate I've never encountered that problem. There again, I suspect that I mostly open the tailgate when parked on the 'flat'.

[ernieb]

I had opened and closed the boot earlier to get a shopping bag out, perfectly level surface. No problems. Then drove to Matlock and parked outside the old Police Station, anyone who knows the area will appreciate that it’s pretty steep. On return I opened the boot using the boot door sensor and let it do it’s own thing then tried to use the sensor again to close the boot, something I do all the time. I have to say I didn’t to the best of my knowledge put any force on the door but from then it just refused to close until I gave it a helping hand. In the scheme of things it’s not a big deal but as my wife said at the time she’d never had been able to reach the handle or want to risk pulling at the side of the door. Just one of those Toyota car mysteries? 

[Mike2222]

On the assumption that this is a specific design feature rather than a random quirk/fault, perhaps has more to do with the safety side of things than the actual boot closure mechanism? ie the auto close is designed to detect when something is trapped in the opening so abandons the closing process if it meets a degree of resistance, ie to avoid injuries. Perhaps this feature cannot work if significantly tilted? Can't think specifically why/how, but would make sense as an explanation as to why it allowed boot auto opening on the slope but not closing. 

[ernieb]

Mike, that’s what I’ve now assumed that because the car was titled forwards some safety feature kicked in, once I gave it an initial start it move via the motors.

[Nick72]

My driveway is sloped. Car usually pointing down the drive (pointing downhill). Inclination is probably equivalent to putting 2 to 3 house bricks under the rear wheels. Steeper towards the bottom (4 bricks). Parked in both parts of the drive in the last 14 months. No problems with opening and closing the boot.

I suspect there's a torque sensor on the boot motor or mechanism somewhere. If the torque is out of range it may refuse to engage the motor. Straight and level with the boot door up there is probably a high torque albeit braked. But if the car is on a steep slope pointing downhill I imagine the centre of mass of the door is now shifted inwards towards the vehicle centre. As a result that's a much lower torque. 

Bizarre though they'd put a feature in for too little expected torque. Too much I could understand. But not too little.

 

Diagram attached.

[Nick72]

On 10/30/2022 at 10:52 AM, ernieb said:

Mike, that’s what I’ve now assumed that because the car was titled forwards some safety feature kicked in, once I gave it an initial start it move via the motors.

Suspect when you gave it a pull you put the torque into the right range since you shifted the CofG of the door. As per diagram above. 

[ernieb]

7 hours ago, Nick72 said:

Suspect when you gave it a pull you put the torque into the right range since you shifted the CofG of the door. As per diagram above. 

I think that's what's happening.  Like all these things there will be variability between cars, sensors, so in a similar circumstance one car might 'fail' and one car might be perfectly OK.

[Nick72]

1 hour ago, ernieb said:

I think that's what's happening.  Like all these things there will be variability between cars, sensors, so in a similar circumstance one car might 'fail' and one car might be perfectly OK.

If it is really steep the torque might actually be in the reverse direction. Boot CofG is forward of the pivot. In that case the motor believes it is encountering resistance so doesn't engage.

[ernieb]

That particular road section is steep and as I said the car was facing downhill so once the the boot lid is open it’s almost being ‘pulled’ over the roof. The good thing is it didn’t take much to get the motor to engage but if your were much shorter, my wife for instance, would not be able to grab the handle.

[Nick72]

1 hour ago, ernieb said:

That particular road section is steep and as I said the car was facing downhill so once the the boot lid is open it’s almost being ‘pulled’ over the roof. The good thing is it didn’t take much to get the motor to engage but if your were much shorter, my wife for instance, would not be able to grab the handle.

Thanks Ernie. So this is entirely understandable logic from Toyota. There was probably negative torque here which is interpreted as resistance to the motor wanting to shut the boot (I.e. someone trying to stop it closing or has head trapped in it or small child getting squished). Safety mechanism for certain.