Alright 3rd gen nerds. Passenger Occupancy System Functionality.

So, the system has 4 hard mounted sensors. Im assume they are just a pressure sensor of some kind but dont know how exactly they operate. They dont appear to float at all so they must (in my estimation) gather input from weight on the chassis.



From the looks the wire mesh attached to the chassis might put tension on the frame as well as the foam as it wraps around the upper.




These next are the sensors. Any guesses to how they operate? The sensors look riveted or spot welded on.

My goal here is to use the factory lower and mate to my Scheel Mann seats.

Come on geeks, anyone got tech insight, schematics or info on this system?

 

Put a multimeter on there and measure resistance when you push them down

 

https://auto.howstuffworks.com/car-driving-safety/safety-regulatory-devices/ocs1.htm

 

gone are the days of silicone bags and pressure sensors.

 

good call.

 

I wouldn't F with them, these have to be calibrated to a certain spec. I've calibrated many of those seats in my day and if the sensors are not installed correctly they won't measure correctly. I'm not saying it can't be done, but if your wrong and screw up there won't be any airbags for your passenger when you will need them. If you really want the seats in there I would say eliminate them and warn your passengers that there aren't any airbags for them lol

 

What happens if you just leave the system unplugged?

 

my intention is to mate the scheel mann seats to the factory base leaving the frame and sensors intact trying to figure if it’s simply pressure based or what.

 

no airbags.

 

They are strain gauges or load cells. This should give you a decent idea of how they operate.

https://en.wikipedia.org/wiki/Load_cell

 

theoretically if i kept some portion of the rails (need to cut some material off the sides to lower the SM seat) they’re bolted or riveted to, welded a base plate to the cut down sides leaving sensors and or carriers unaffected i should be able to have functioning passenger occupancy sensor.

 

Not getting into that... not my zoo so to speak. You asked how the sensors work I provided an answer. That seat frame is designed to have a deflection area to allow the sensors to function. Any modifications to that are on you and how much you value the safety of your passengers in said seat.

 

totally get that. I wouldnt be cutting into that deflection area (in theory) In the attached image my idea is to cut the welds for the front tray, then cut the side rails at the red lines. Leaving the sensors, most of the rails and floor mounts. The OCS would remain exactly where they are/were and the deflection components.

To the side rails i would weld support bars or a plate that the seat bolts to. Maybe using rubber bumpers between the plate and the deflection end of the sensor so when someone sits on it it presses the sensor.

From a purely mechanical standpoint any thoughts on this idea? So long as I kept all portions of the frame that allow for movement im basically just changing some sheet metal above all that.

 

Just discovered something interesting.

The seat I bought to cannibalize is from a 3rd gen Tacoma, it has the ECU p/n that works with the metaltech box. Im going to check that against the ECU from my factory seat. If it's the same, problem solved.

Metal Tech 4x4 told me their box doesnt work with the 3rd gen tacoma as the ECU's were different but it appears they might not be.

 

Pretty sure they're ordinary exhaust sniffers.

 

I understand what you are doing, but it's more than just leaving certain aspects of the seat frame intact. The factory seats with sensors are all engineered so that the weight is distributed to a certain point that the sensors read correctly. Just because your putting an aftermarket seat on the seat frame doesn't mean everything will be ok. Your changing the weight distribution to those sensors, weight distribution can change base on stationary, forward/rearward motion, etc..