What do the electronics/wires do in the seatbelt receiver?

Recently opened up the driver-side seatbelt buckle receiver (the thing you "plug" the seatbelt into) to clean out some gunk and in the process damaged the wires and little micro-chip looking thing inside.

What is the purpose of this wiring?

At the time I was just assuming it had to do with a seatbelt notification sound, but then in thinking back I don't think this truck ever had that sound.

I've read there is wiring/electronics in the part the seat belt comes out of that is used during a crash to activate a some ultra-fast locking of the seat belt.

I'm concerned the electronics in the receiver is related to that. If that's the case, I would replace the receiver, but wanted to get some input first out of curiosity.

 

Other thought: Could also be related to whether the air bag would go off? That would also be a good motivation to replace it : )

 

They just drive the seat belt light on the dashboard as far as I know.

 

Seatbelts rapidly auto retract by explosive charge upon impact in an accident detected by deceleration sensors.
Wiring will be shielded in yellow on these parts.
The wiring under seat activates dash light @Andy01DblCabTacoma

 

It's unclear in service info whether or not the seat belt switch is used by the airbag system, it shows to be connected to it as well as the body ECU (to control the warning light and buzzer) on the wiring diagram but the SRS section in the manual makes no mention of it.
On newer systems the seatbelt buckle switch tells the airbag module whether or not the seabelt is fastened for deployment calculations, logging and warning light control.

The pretensioner portion of the seatbelt is in the seatbelt retractor assembly not in the latch side although there are some vehicles that do have it in the latch side.

 

Not on first gen Tacomas they don't.

 

True, not all 1st gens
If it's got air bags, it's got auto retract.

 

and on that note, time for some documentation because someone is bound to ask how to dispose of those explosive charges on their auto retracting seatbelts...

 

How about that! I learned something today.

 

I remember back in the day when working as a tech at Lexus. Another tech had to remove and replace a seat belt.
He used an impact wrench to loosed the bolt and the auto retract charge went off, scared him shitless. It was funny.

To the op. The wiring in the "buckle" part that you took apart only tells the car when you buckled your seat belt.
You should be able to find one cheap at a junkyard but it's weird that your truck seat belt chime doesn't work.

 

Would've never guessed you would be working with explosives while working on a seat belt. Thanks for the info.

 

The chime can be disabled - maybe his is.

Off the top of my head, I don't recall if this is done via OBDII/ECU or if it's like the way we set the alarm/remotes (ignition on/off door open close BS). It can be done though. I remember a dealer tech asking me if I wanted it disabled. I said disabled and haven't heard it since.

Then again, maybe he just cut a wire lol

 

Since I've owned mine it's never been on. Fine with me though.

 

I don’t think disabling it is an option on anything other than a 3rd gen.

 

My 2002 disagrees

 

I didn't think it was possible.

 

Thanks for the input everyone.

Based on the replies, it sounds like I'm safe to leave it as is?

Other notes:
+ Never had a seat belt chime in this truck - before or after damaging the wire in question. I'm the second owner so it's possible first owner had the charm disabled
+ Regarding the seat belt light in the dash - I'm not seeing that light up post the wire being damaged, but it's possible the bulb is just out. I need to pull it apart to replace some of the bulbs in there.

 

It’s just for the seat belt warning light on the dash. Trace the wires down below the seat and you’ll see it connected to a single white connector that runs under the carpet.

The seat belt locking feature in case of an accident is all mechanical. Nothing to do with the electronics in the seat belt receiver.

Air bags are controlled by some electronics that will always be indicated by yellow harnesses/connectors. Again nothing to do with the electronics in the seat belt receiver.

 

You can easily disarm the chime but disconnecting the single wire connector under the seat.