Mazda 6 Mk2 Rear Seatbelt Issue

I’ve got a 2010 Mazda 6 with about 100,000 miles on the clock. It’s a great car – lovely to drive and very reliable. However it did something interesting to me the other day.

I folded the rear seats down to get a bike in the boot. When I tried to put the seats back up one side wouldn’t move – the seat belt had locked itself. I suspect the inertia reel units have something to stop them locking in the down position and this has stopped working due to age.

The seat is designed to be worked on when it is in the upright position – locked down everything gets much harder! I wanted to take the car to the garage for them to have a look but all the Mazda garages are closed due to COVID-19.

There is no access to the inertia reel unit – it is in the top of the seat. The back of the seat (the only bit accessible) has a steel panel welded in so I presume the access is via the cushion at the front of the seat. The seatbelt lower attachment was hidden under the seat squab. So I took the seat out.

The rear bolts are hidden under a plastic trim under the boot floor.

Plastic trim removed

If you are unfamiliar with trim fasteners then there are generally 3 types:

  1. The friction ones that normally break when you try to remove them;
  2. The half turn ones that sometimes break;
  3. The centre-pin ones that are ok if you can get the pin out.

The boot trim is held in with the centre-pin trim fasteners. Get your finger-nails round the edge of the pin and pull; then the whole clip will come out easily.

Centre-pin trim fastener

Then remove the 3 bolts and 1 nut that hold the back of the seat in place. These are tight as they secure the seat belts too.

With these out it is time to grub about on the rear floor. There are two bolts that hold the front of the seat in place, hidden under plastic trim that pulls off easily. In my case one was easy to get at if I stood on my head and used an open ended spanner. The other was in the centre of the car and much harder to get a spanner on. Fortunately with the other bolts out I could move the seat enough to get a socket on the bolt.

Lower seat belt anchorage is now accessible – please excuse the mess – I’ve got kids!

With the seat moveable I could undo the lower seat belt anchorage. Now I could unfold the seat so the back was upright and check the mechanism worked ok. It was fine – when upright in its normal position the inertia reel worked ok – locking and unlocking correctly.

Getting the seat back in was easy. The bolts behind the seat need to be done up very tight as these help secure the seat back with its inertia reels; the others are less crucial.

Now I just need to remember to tie off the seat belt before lowering the seat!

Stop the problem happening again

When the garages reopen I will get them to take a look and maybe replace the inertia reel unit. I’m pretty sure it is ok but if any wear is present then that isn’t a good thing.

4 thoughts on “Mazda 6 Mk2 Rear Seatbelt Issue

    • Good to hear it is useful!
      Tip is to blank off the seat releases in the boot with gaffer tape and stick red tape to the interior releases so you remember to tie off the seat belts before you fold the seats – otherwise you’ll be doing the job again…

      Liked by 1 person

      • I had that problem, I removed the bottom belt anchor bolt, let the belt retract, lifted the backrest, then replaced bottom bolt. Worked for me


      • On my car I can’t get to the bottom belt anchor bolt. I really really wish I could – I have to redo this job everytime I forget to tie off the seatbelts before folding the seats down.


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