Aftermarket seats in 3rd Gen some info.

Not sure if same on 3rd gen. On a 2nd gen that open slot runs along a metal rail that is riveted to the inside seat slider. The sensor is “broken” when the seat is positioned so the rail is in between the channel/slot. The rail only runs a small portion of the slider, and if I recall, when the seat is way far back it no longer disrupts the sensor. Basically tells the srs ecu you are in X proximity to the wheel. The way to replicate stock is fab up your own rail system essentially that is the same length and position from the wheel/seat bolt mounts/whichever frame of reference you pick, and affix the sensor to the seat in the same principle. The only problem is you also have to verify those measurements against the seat travel. Some aftermarket seats have more or less travel than stock.

Hope that makes sense. And if your 3rd gen sensor doesn’t appear to work like that then ignore what I said as it must work differently, but has some sort of way to sense where it is in relation to seat position.

 

It might be a neat idea to use a multimeter and reverse engineer the electrical voltage/resistance from where a stock seat sits, in about the same position as the new seat. Measure, then just fuss with the sensor until it produces the same readings and lock it in...

 

Alright, so I realized something messing with the finishing touches on this seat install... This sensor's top edge is magnetic. That answers my question of how it senses the position. Now I just need to try the multimeter trick to see what stock reads and then recreate. I wonder if just putting a small piece of metal there would do the trick?

 

That’s essentially what I was saying when I said recreate the stock rail setup.

 

Is that sensor meant for distance? Or to insure you're actually "locked" into one of the adjustment notches? If you're not fully locked into a notch, the magnet on the sensor would be picking up air (instead of metal on the frame) and know the seat wasn't fully latched into place and prevent the airbag from beheading you if your seat launches forward?

Damn that was long winded, I honestly have no idea how it works, just spitballing.

 

it’s a distance thing. When you are at a certain distance the rail rides in the channel, at other distances in seat adjustment it’s out of the channel. So not a seat lock sensor.

 

Looking great!

Are these seats thinner than the factory ones? Been thinking about the limited space for rear passengers and how much more space we would have if the seats were a couple inches more thin.

Any suggestions for thinner and equally or more comfortable seats?

 

So what's plan B if the 2 Ohm resistor doesn't work to turn off the airbag dash light? No luck with the resistor here, no idea where to turn next.

 

Can you show a picture of how you hooked up the resistor? I failed in my first attempt. I read elsewhere that a 2-4 ohm resistor should work, so if you're certain you hooked it up correctly, then perhaps try other resistor values between 2 and 4.

 

I tried using 2 - 2Ohm resistors, and still no luck.
Weird, because it sounds like most people are able to get the light to turn off.

 

how long have you had the seat out, did you turn the car on without it in there? sometimes it takes a bit for the ECU to reset the light. on my 2nd gen I cut and soldered to the wire then heat shrink over.

 

2" lower? How tall are you?

 

5'11" - I guess I have an unusually lengthy torso?

 

I've been playing with the OBD Fusion app for my iPad with a bluetooth LE OBD2 adapter. I bought the Toyota extras pack for that app, to get access to more sensor values. One of the groups of sensor values that I noticed last night is "Occupant Detection". Under that category there are dozens of parameters that can be sampled related to Occupancy Detection. I would imagine that I could read the proper voltage for the stock drivers seat sensor. Then, find a way to recreate that read voltage for these aftermarket seat upgrades (by manipulating the stock sensor). This would ensure that the driver's front airbag would deploy as it normally would with a stock seat.

 

Hey Reymataco, have you figured anything out about the occupant sensors for the passenger seat? I just finished replacing the carpet and two Caribou seat rails when I realized (too late) my passenger will not have airbags. I have pulled the OEM system with the 4 individual sensors from the seat and attached the wires, but it's all sitting in a clump underneath the seat. Metal Tech 4X4 told me they haven't made the bypass module since the pandemic or I would have purchased that. I understand the risk of having the airbags on all the time but kids do not ride in my truck just two adults. Do you know of a way to fool the system to where it's locked on? Thank you very much.

 

I've only done my drivers side seat so far, but am considering the matching passenger side install. I will have to dig into it when/if I take that plunge. But the switches you are asking about are just pressure switches in the 4 corners of the seat, if I recall correctly? Those should be easy to just press down to be "on" all the time. Airbag in the front passenger would deploy regardless if there is a passenger, then. The sensor I mentioned in my previous post helps the airbag deploy at the right speed given how far forward or backward your seat is on the rails. That one you could sort out with the OBD Fusion app, I would think.

 

And yes the sensor you are referring to is on the drivers, I was going to take my off and just plug it in since I didn't have anywhere on my new rail to fit it but now that I understand it's magnetic I'll play around a bit with it. So thank you for that.

As for the passenger...I am unsure as to if they are pressure sensors or not. They seem like they are triggered by magnetism or angle or if they will even work outside of the seat at all I am unsure.

http://www.tsienna.net/system_description-2392.html

Looking here they give a surface level description of how it works, and after taking it apart, the sensors do not come in direct contact with the seat at all; rather it's the brackets that are pressed down which will rotate the sensors. I'm wary though, to plug in my battery with the sensors scattered all over the floor because I don't want the vehicle to throw a permanent code because it thinks my seat went through an event horizon. If I can strap a piece of wood or metal to them and tighten them down with some fuel line clamps then I'll do that but I am trying to gather all the info I can first so your input is very much appreciated thank you.

 

For a few bucks, if you have a phone or tablet, get a cheapo bluetooth OBD2 dongle and buy an OBD2 app for your device. Assuming you have a phone or tablet already, for less than $50 you could get those pieces in order to read the current "distortion" values read when someone is sitting in the front seat. Then, just recreate those values. How to recreate those values, is another matter... I haven't tried, so I can't help you much there.

 

Ah I appreciate it, I have already demolished the seat and removed the sensors, now they are just a pile of wires. This is one of those instances when I took the torch and ran...into a fuel tanker. I figured everything would be easy and all plug and play until I saw that my seat sensor was not a bladder system. I'm not sure what I'm going to do as the final fix but if I get it to work without errors I will definitely let you guys know. I tried the customs shop in town but they apparently have never installed aftermarket seats in a Tacoma and then the dealership to see if they could hook it up to their system which runs Techstream and permanently enable it but of course that was a shot in the dark... Looks like this will be a lot of trial and error. Also, if anyone has that Occupant Sensor Bypass Module please let me know I'll buy it off of you.