Seat Belt Switch - Air Bag light
Air bag light comes on or won't go out when the Seat belt is done up. If you drive with the Airbag light illuminated then in the event of an accident it is likely that the Air bags will be disabled and won't deploy. 

I have been told by Honda Australia that - unlike the U.S. - there is NO Limited Lifetime Warranty on Seat Belts.

The Section “Warranty Coverage” is NOT INCLUDED in my owner’s Manual. US handbook has this under the heading:
Seat Belt Switch - Picture by sontt007 on - I haven't taken one yet
micro switch - just clips to the bracket
I have been having problems with the Air-Bag light for some time. When it first happened I had a look at the codes  - I have a Honda HIM and Honda software running on my car-pc - it identified a Driver seat belt sensor error.

This condition had been getting worse and if I watched the lights closely I noticed that every so often the seat belt indicator was not coming on as the seat belt was released. I was interested to see if the metal actuating slide that drives the micro-switch lever could be binding in any way. Dust can build up in here and cause a bind in the lever or the lever can get bent slightly and not contacting the plunger correctly.

It was clean and the Micro-switch lever was not bent or fatigued. Micro switches normally have a definite click as the internal spring loaded switch flicks between the two contacts and this is independent of how fast or how far the actuating lever travels, it just has to move and release enough to allow that action to happen. The switch action occurs over a very small amount of the total lever travel.

FYI the switch in this unit is a double throw single pole, IE A changeover switch.

Testing on the bench proved it to be working faultlessly in both directions. One of the tests I did before removing from the vehicle was to slowly withdraw the belt from the buckle, I could get it to fault more often than if I ejected it quickly, again, that’s strange if it’s just a switch contact problem as in a micro switch, the internal changeover speed is not affected by how fast you move the lever.

I think there is a possibility that in my case, the sealed plunger which is driven into the switch by the lever may have been binding. I read somewhere of the red sealing ring being levered out with a pin and someone spraying cleaner into the micro-switch (ruined the seal). However it may have just been the rubber/plastic sealing ring that was the problem after all.

I simply sprayed the shaft with a special contact cleaner and switch lubricant (one that leaves no residue for dust to adhere to and is plastic friendly). I also sprayed/cleaned the under-seat connector (seatbelt cable connector)  in case of intermittent problems.

Assembled and back in the vehicle and it’s been perfect for the last 6 months, it will be interesting to see how long it holds up.

UPDATE: Eventually the problem came back, having another look at the switch and further testing indicates a problem with the tiny rubber seal around the plunger. This seal deteriorates over time and gets hard or sticky, either way the micro switch plunger appears to be getting hung up on this seal. I cut the seal around the plunger and refitted the switch. Been a few months now and no further problems.

I’ve serviced various equipment running high cycle “sealed” micro switches and over time I can’t really remember having to replace them for an intermittent switch contact, they either worked or they didn’t, anyway, I thought this may be of interest to someone.

BTW, the micro switch and lead assembly just pop out, carefully though, it’s a plastic locating tab on the switch that locks into a metal spring clip/retainer.
Warning: When working on any part connected to the SRS system - Disconnect the battery and wait until all residual power has discharged - around 5 minutes - check your manual for other precautions.

The seat belt light should change state the instant the seat belt is buckled or undone. If not, the switch may be faulty - assuming the belt light indicator circuit is working correctly. With the seat belt light on (unbuckled) and the vehicle turned ON, the air bag light should do it normal check cycle and then go out.

The seat belt light should go out when the belt is engaged. Both actions can appear normal but the air bag light still trips.

During the transition of the switch state, as the belt is done up or undone, there can be a momentary bad contact in the switch or connector which can cause a delay of the indicated state, this results in the air bag light turning on.
I have a feeling that it may not be in the Canadian owner’s manual either?  Spent wasted hours trolling through various AU Honda forums and it’s the same story. Owner contacted Honda and was told no lifetime limited warranty, said it only applies to US. Post after post where owners are paying through the nose for new seatbelts.

With this in mind I decided to repair the seatbelt switch - IMHO this repair is NOT a safety issue, you are doing NOTHING to the seat belt buckle locking mechanism or to it's mounting point or mechanical integrity.

“Warranty Coverage - U.S. Owners section”

Seat Belt Limited Warranty - a seat belt that fails to function properly is covered for the useful life of the car.”

Canadian Owners, Please refer to the Warranty Manual that came with your car.”