Passenger seat belt mechanism sticking

Hello! If you're speaking of the part where the seat belt buckle connects to, I would suggest first spraying so.e penetrating oil in there and let it sit for a few minutes. I'm not sure of where you are, but here in the USA we have 2 brands, WD40 and PB Blaster. You should be able to get something at the local gas/petrol station, service station, or car parts store for cheap.

Often times these things get a little rust or dust in them and that causes them to stick. The penetrating oils do an excellent job of cleaning that stuff out so it works like new again. You can also use it in your cars keyholes by spraying the key and inserting it into the hole and turning it back and forth a few times.

Try that and I'll try looking up your car to see if there's anything else that I can suggest if needed. Good luck!

No sorry I wasn't clear. I am talking about the mechanism in the body column that houses the take-up reel. I have since learned that the Matrix uses a pre-tensioner system which is constantly 'online' unless the battery is disconnected. It is integrated with the side impact air-bag system. (SRS). In 'normal' emergency stop mode it will lock and slightly tighten the belt around the person. In a crash, pellets in the take up reel ignite and a bunch of things happen. End result is the assembly has to be replaced... it is a 'hazardous' component and wisely left to mechanics qualified in dismantling and setting it up. One side effect is a film of dust is ejected into the passenger space. I mention that because when the take up reel started sticking when trying to pull it out to fix around a person I asked my local Halford's service station (UK chain) to look at it when they were doing some other work on the car. The mechanic hit it with hammer 'in just the right spot' and didn't charge me. Not long after it jammed up completely. But at the time I noticed my passenger compartment had this film of coarse-ish dust in it. In researching for this inquiry I discovered the use manual warns specifically against doing that because it is likely to ignite the charge in the take up reel mechanism and the result will be dust in the car and the whole assembly will need replacing!!
The only concern I have, besides the obvious about Halford's competence, is that the car repair manual indicates that the status of the take-up reel mechanism, as being 'fired', should reflect in the display of the 'Air Bag' status indicator during the post-ignition check sequence. It doesn't indicate any problem. I will check to see if the belt is twisted inside the column.. but if that's not the problem, and it doesn't feel like it is, then I guess I'm in for another big bill I can't afford...

Well it certainly seems like you've been doing your homework. Like the Halfords mechanic, I'm not too familiar with this setup. I looked up the similar US market vehicle (Hyundai Elantra apparently is mechanically similar) and managed to find instructions on how to replace the reel and tensioner. As far as I can see, there's no need for you to go pay an exorbitant repair price. I'm including images pulled directly from AllData.

I will say that I can't guarantee that its exactly the same as your car, but it should be pretty close to the same. Auto engineers love using and reusing their designs in order to save time and money.

Check that out, compare it with your own information, and let me know what you think.