S5 Seatbelt Icon Flashing On/Off
 

Hi everyone,

I wanted to see if anyone could help me with my S5 GXL. My idiot cluster keeps flashing on/off the seat belt warning icon. It will go away and with some movement from my body against the seatbelt it will turn on. When I tug on the seatbelt it will go away for a few seconds only to come on/off again later on during my drive with the vibrations/bumps of the road. I am planning on taking the car to the dealer to have the auto rails and motors replaced since they have shown signs that they are slowing down. I just need to call Mazda USA so they can schedule the appointment at the dealer and ship the parts. Any suggestions?

It sounds like it's the capacitors in the cpu. Mine was doing the exact same thing, though at first it was ambient temperature related. Whenever the temperature dropped outside (like at night) the seat belt light would start flashing. I also noticed the security light doing the same thing. When it was armed it would flash faster than usual. Eventually these things were happening constantly, so I couldn't take it anymore and finally fixed it.

Take apart the cpu and replace all of the capacitors on the main board. You can also replace the ones on the flasher board for good measure. Capacitors deteriorate over time and eventually start to short causing weird electrical gremlins. Mine weren't even leaking when I replaced them, but they were still bad.

Does the CPU use specific capacitors?

All capacitors are kinda specific. Their function is measured in Microfarads, IIRC. They have a number on them that tells you, just match them up.

Before you get all up in the cpu, I'd check the obvious- and simplest to fix- culprit, which is the contact switch in the seatbelt receiver.

Also, on a side note, Mazda dealers detest replacing the mousetrack units and unless yours has totally failed and has cables hanging out, I doubt they'll authorize a warranty replacement. However, should a miracle occur and "appearing to slow down" actually triggers the replacement, be prepared for the a and b-pillar plastic to be damaged.
It may be worth it to remove the pieces yourself (they will still break) and save the hassle of fighting with the dealership over ancient, crumbling plastic.

Gabriel,

Does your FC have the passive shoulder belt system or standard seat belts? I agree with clokker, check the seatbelt receiver first. If you have the passive shoulder belt then the most likely cause is the fingers are worn/broken inside the passive shoulder belt retractor assembly. Refer to your FSM around Pg S-16, it is Item 6 from the diagram. The fix would be to replace the assembly. FWIW, this happened to me about 20yrs ago in my 91 Coupe; replaced that assembly and my flashing seat belt warning light went away.

Does this help your situation? Please let us know what you find!

Cheers,
George

Coincidentally, recently my seatbelt flasher and security lights started flashing constantly. If my lap belt is not latched, then the warning/reminder bell will ring, but if the belt is latched, then the bell stops, but the light continues flashing. I was planning to disconnect the receiver switch on both the driver and passenger sides and see if that resolved it, but I suspect capacitors is the best explanation for this sudden spurious symptom - at least in my case. Thanx 90FC.

cone_crushr,

Since you described the security light & seat belt light problem then I would suggest inspecting the Body CPU for defective capacitors or other bad components. Post pics when possible, please.

Cheers,
George

George - just to confirm, by replacing the assembly you're referring to the whole retractor assembly located under the arm rest correct?

Gabriel, yes replacing that component would fix the problem. It would also be a good idea to check the body cpu for any damaged components.

There are specific capacitors, yes. You need to match the capacitance, voltage, and of course size (for fitment within the case). If the voltage spec is higher that's fine.

Like the others have said, check connections or sensors first.

No problem. I've just been looking for a reason to post my experience. :)

In my case the seat belt light would consistently flash and beep with the seat belt receiver wire plugged in. The beeping would go away when I unplugged the wire, but the light would still flash.

FYI, I opened my CPU and found that all my 16V/10uf capacitors were spewing electrolyte. Desoldered the four from PCB and new ones will hopefully be soldered-in next week. I never would have figured this out without forum help - RX7Club to the rescue again!

cone_crushr,

Glad to lend a hand! Did you take any photos of the bad components? Would you also list which ones were bad? This would help others identify potential problems with their Body CPUs.

Cheers,
George

Changed out the whole Seat belt Rectractor assembly, that did the trick! thanks!

Gabriel,

Good to hear that the new retractor assembly fixed your problem! I'm glad to lend a hand.

Cheers,
George