Anyone know how the passenger seat detection system works?

[rage2]

OK so I swapped the stock seats for some Sparcos (will have pics later after I wash the car) and I was trying to figure out how the sensors work to detect if there's a child seat (airbag off, seatbelt warning on) or a passenger (airbag on, seatbelt warning on).

Before taking the seats apart, I thought it was a simple weight sensor, boy was I wrong, it's the most complex thing I've ever seen for such a simple task. The stock seats sit on 4 pivotable points, so based on weight front of seat or full seat, it pivots differently. Each pivot point has what looks like a level sensor, and a harness connects all 4 of those pivot points into a little module called the "Occupancy Detection Computer". From there, it plugs into a harness to the car.

With the new seats, obviously, there's no pivot points like the stock seats, so my first test was to see the behavior without the little computer plugged in. Airbag light is on, Airbag is "OFF" and the seatbelt light keeps blinking regardless if the passenger seatbelt is plugged in or not. So next, I plugged in the computer but not the harness for the 4 level sensors, and same behavior.

I probably won't have a child seat in there, but I would like to rig up a small weight sensor in the seat that sends a signal back to the car, bypassing the occupancy detection computer, with either passenger in seat or no passenger. So with no passenger, airbag off, no seatbelt lights, no warning beeps. With passenger, airbag on, seatbelt lights + warning beeps.

Anyone know what the pinouts from the occupancy computer to the car is? What voltages to send to trick it into passenger or no passenger? Or am I SOL and stuck with no airbags on the passenger side?

[rage2]

Oh as a note, the driver side is easy. There's only a seatbelt sensor, and a seat positition sensor along the stock rails (to trigger airbag deployment rate?), so that worked just fine.

[blacksan]

Geeez, you picked a tough one!

[Presto]

How did you mount the new seats? Did you remove the stock rails and attach them to the new seats?

[rage2]

Originally Posted by blacksan

Geeez, you picked a tough one!

Would you happen to have the pinouts from the Occupant Classification ECU to the Center Airbag Sensor Assembly? Pinouts and expected voltage/data would be ideal, that way I can make my own weight sensor and my own Occupant Classification ECU.

Thanks!

Originally Posted by Presto

How did you mount the new seats? Did you remove the stock rails and attach them to the new seats?

Yes, I basically removed the stock seats from the stock rails, welded a new frame that connects the stock rails to the new seats.

[blacksan]

Originally Posted by rage2

Would you happen to have the pinouts from the Occupant Classification ECU to the Center Airbag Sensor Assembly? Pinouts and expected voltage/data would be ideal, that way I can make my own weight sensor and my own Occupant Classification ECU.

Thanks!

PM me your e-mail and I will send the HUGE PDF file!