Base model BRZ - What do you need to bypass airbag light errors with race seats?
 

I've just replaced the front seats with race seats. The connections are actually pretty simplistic, and there are only seat belt (carried over) AND airbag plugs for driver, and there's also an occupant sensor for the passenger.

• Airbag circuit resistance: I did use what worked for last gen BRZ, 3.3 ohm resistor, and it DID NOT work. Later, I measured the resistance from the airbag circuit using a volt-meter, and it was 0.3 ohm.
  • Has anyone also observed this? I've ordered resistors at that rating, but I am yet to try it.
  • I dropped the resistance to 0.6 ohm by parallel-connecting all 3.3 ohm resistors I had in hand, but it was still not enough to prevent the light from coming on.
  • Besides 0.3 ohm resistors, I also ordered these simulators, since they look clean and neat: https://bradshacks.com/product/airbag-simulator/
• Occupant sensor: We have this elaborate 4-sensor plug under the passenger seat.
  • FIRST OFF, it doesn't look like a pressure sensor, since it's installed right by the rails. Perhaps rail position sensor? I did not see any other sensor, but might have missed something..
  • Do we need this to keep the light off?
  • For the time being, I keep the OEM seat right by the passenger door and plug this in to eliminate its impact while I experiment on airbag plugs, but I'd really not like to remove all that harness from the OEM seat bottom, if at all possible : )
  • Just ordered this sensor to experiment with it: https://parts.zeiglersubarumerrillvi...4084CC010.html

https://thumbnails-photos.amazon.com...Fh-iYJiH0THNlx
Feels like it would be so much easier to just change the driver seat!

https://images.simplepart.com/images...1_64001828.png
The occupancy sensor in orange..

I am also curious about the occupancy sensor's method of functionality and how it can be dealt with properly.

3.3 ohm resistors work fine. Like you said, its way easier to just change the drivers seat.

You're on the right track with the occupancy sensor. I also ordered that same part # hoping its the complete occupancy sensor x4 + harness - Saw on a FB group post that someone took it off their stock seats which required quite a bit of taking apart.

Ok here's hoping that harness would be the end of it! Besides the occupancy sensor, the harness also lets you plug in the seat belt plug. I guess you could figure that out without it, but this would make it a clean install. I'll try it out as soon as I receive the part.

FYI

64084CC010 - I was able to order this part at my local dealer. It's actually missing the 4 sensors that are attached to the seat rail (only includes the cabling).

Shoot, do you know what else needs to be ordered?

Anyway, I ran out of patience, and looted my OEM passenger seat for the parts. In short, NO WARNING LIGHTS!


https://thumbnails-photos.amazon.com...Fh-iYJiH0THNlx
https://thumbnails-photos.amazon.com...Fh-iYJiH0THNlx
With everything connected, there're no longer any lights!!!

https://thumbnails-photos.amazon.com...Fh-iYJiH0THNlx
I fixed all the sensors by the race seat's base mount to make sure the sensors are not hurt by harness, etc. They are not very well protected as they are.

https://thumbnails-photos.amazon.com...Fh-iYJiH0THNlx
https://thumbnails-photos.amazon.com...Fh-iYJiH0THNlx
All done!!

occupancy sensors are LIN bus based. They are actually similar to Load cells. So they measure deflection of the weight on them. No real way to bypass them other than unbolting them and leaving them on the floor lol.

I will be working on a device soon that will be able to connect a different sensor into the system. But that will be later on.

Are you able to confirm that the passenger airbags work with this setup? i.e. if you sit in the passenger seat, is the "passenger airbag on" light on instead of the off? I have seen similar setups where the occupancy sensor is retrofitted to aftermarket seats and this works, but want to ensure it works in gen 2 as well.

If you leave the sensors there but without any weight, there is no way for the seat to tell if there's a person on the passenger seat. So most likely the airbag on light will not be showing. But that might mean that the airbags will not deploy in case of an emergency.

I was wondering if fastening the sensors to the bottom of the seat body as shown in that picture was sufficient for them to sense the pressure of someone sitting in the seat and produce the airbag on light. If so, that would be an easy setup that would make me confident the airbags will work in an accident with a passenger.

Another person reporting in who has been trying to kill those lights. I've tried several different resistors in the airbag, seatbelt, and occupancy harnesses. No dice so far. I'm also pulling/reseting codes. I have a friend who just replaced the drivers seat and kept the seatbelts and the resistor approach worked for him.

Mine is track-only so I have everything removed. My next attempt will be to install the sensors from the seats and disable/bypass them 1 by 1.

Not with them just zip-tied to the bottom of the seat. However, the way they mount between the seat and sliders, it wouldn't be difficult for a company that makes seat brackets to make one that can accommodate the sensors, and aftermarket seats might be close enough in weight to get away with it.

There are two smaller bolts that attach each sensor to the sliders, and then one larger bolt that connects the sensor to the seat.

-Mike

No amount of resistors will be able to bypass the occupancy sensor. As a sensors are digital based. Nothing analog. The resistor method would be for the actual airbag. I'm working on a digital emulator that will make the system always think their a passenger.