Seatbelt mechanism issue - help please

[Artsy]

Hi All,

I've been digging in the threads to find a similar topic but not finding exactly what I need.

I'm having issues with one of the seabelts in my 2010 Prius. It affects one of the rear seatbelts and is made worse by the fact that it's the kids using it.

More specifically what happens is the following:

1) Belt works as normal to put on and can be pulled all the way out
2) Belt retracts as normal
3) If you guve the belt a sharp tug, it locks up as expected

The issue I'm having is that once locked, the belt will only unlock (and allow it to extent) if it is fully retracted. I.e. I can't retract a little to release the locking mechanism, it has to go all the way back in before it can be used again.

Any advice on this?

Thanks in advance and apologies if this is the wrong area of the forum for the question.

[simon_harris]

I used to have a seatbelt like this - it is very annoying.

I never solved the problem.

[s94wht]

I've seen plenty like that before. I just always figured that's what they're supposed to do. It seemed like coincidence that a fault point would also happen to be right where the belt was fully retracted (which isn't obviously fully retracted as one side end is still attached to the seat.

[Artsy]

That's the annoying thing.

My eldest who sits on that side is forced to take it of completely if he jams it and then put it back on whereas it should normally retract a little and then the jamming mechanism should release.

Looks like it might be a complete replacement job to fix or just try and ignore as he gets older.

[Panamax]

Does it jam with other passengers or is it, perhaps, his technique?

I had a seatbelt like that and sometimes wondered whether it was just the angle of the reel fitting and the belt not coiling in neatly.

These belts are sometimes happier rolling back gently than being yanked and dropped.

[Artsy]

I think it's the belt rather than him.

On a few rare occasions it has worked properly i.e. recoiled a little and then released but this is probably like a 1/20 occasion...

[FMOB]

The mechanism is probably a bit sticky and the full retract provides a shock that temporarily releases the sticky part of the mechanism.

I wouldn't suggest poking about in the mechanism of the seatbelt so if it is a big annoyance then a replacement is probably the easiest solution.

[Artsy]

Thanks. Looks like it stays as it is until it's a bigger problem.

[Abbott]

There is nothing wrong with the seat belt.

It is called an ELR/ALR seat belt and has 2 modes of operation. ELR is the Emergency Locking Retractor and it operates as normal only locking after sharp deceleration or fast pull out of the webbing.


The Automatic Locking Retractor (ALR) mode(child restraint mode) locks the seat belt for child restraint installation.When ALR mode is activated the seat belt cannot be extended again until the seat belt tongue is detached from the buckle and fully retracted. The seat belt returns to the ELR mode after the seat belt fully retracts.

Here is an extract from the Prius Manual

Edited by Abbott on Wednesday 3rd April 15:29

[Artsy]

Just to check.

Does this mean if an adult was using the belt it would retract and release from a more extended position than it would if a child was using?

[Abbott]

Artsy said:

Just to check.

Does this mean if an adult was using the belt it would retract and release from a more extended position than it would if a child was using?

It does not make any difference if it is a child or adult.

To switch the retractor into ELR mode you need to pull the seat belt all the way out. It will then ratchet back in as you release it. At this point pulling on the belt will feel like it is locked.

The retractor switches out of ELR mode when you release the tongue and allow the belt to fully return.

[Artsy]

Just saw the screenshot you added thank you for this.

I'm still not 100% sure about this as it appears that once it locks it always has to go all the way back.

The other belts aren't like it but I'll do some further testing to see if this is indeed the case.

[Abbott]

Artsy said:

Just saw the screenshot you added thank you for this.

I'm still not 100% sure about this as it appears that once it locks it always has to go all the way back.

The other belts aren't like it but I'll do some further testing to see if this is indeed the case.

The function is to give a more positive way to secure a child seat. So It is my experience that most OEMs will have this feature on the rear outer position seatbelts and may be the passenger seatbelt.

[Abbott]

This ELR/ALR device was mandatory for all passenger cars in the USA. I think there was a proposal to drop the requirement as more and more cars were fitted with ISOFIX mounts for child seats but I believe they continued the rule.
So for cars that you would also see in the US market most OEMs would apply the same system to EU cars.

[donkmeister]

Abbott said:

Artsy said:

Just saw the screenshot you added thank you for this.

I'm still not 100% sure about this as it appears that once it locks it always has to go all the way back.

The other belts aren't like it but I'll do some further testing to see if this is indeed the case.

The function is to give a more positive way to secure a child seat. So It is my experience that most OEMs will have this feature on the rear outer position seatbelts and may be the passenger seatbelt.

Beaten to it.

On my Lexus family bus, it is triggered when one of us is in the back and needs to stretch to grab something. Then it's like being trapped by a boa constrictor as it only gets tighter until you remove and reset the belt.

When the US introduced LATCH (isofix by a different name) they found people didn't trust child seats that weren't also strapped in, hence the need for belt restraint despite solid mounting lugs below.

[Artsy]

Just did some thorough testing on the belt.

It appears that the issue arises when the belt is pulled past a certain point.

As my kid was in a car seat it was probably quite extended and any forward movement with it just locked it anyway.

I noticed that the sound of the ratchet? changes after a certain point and the belt locks unless fully retracted.

At normal extension it appears to work fine after all.

Many thanks for all the responses as this has now put my mind at ease that the car isn't due another £300 or something to fix the issue!

[Abbott]

Artsy said:

Just did some thorough testing on the belt.

It appears that the issue arises when the belt is pulled past a certain point.

As my kid was in a car seat it was probably quite extended and any forward movement with it just locked it anyway.

I noticed that the sound of the ratchet? changes after a certain point and the belt locks unless fully retracted.

At normal extension it appears to work fine after all.

Many thanks for all the responses as this has now put my mind at ease that the car isn't due another £300 or something to fix the issue!

It is quite a complex set of small gears that throws a small lever to change the locking mode.

Since I left work I have lost access to some nice animations that explain the mechanism. This video will give you a feel for how complicated it is.



Dont worry the light plastic parts move metal lock dogs that carry all the loads