Wiring for the Pass seat weight sensor?
 

Working on eliminating the weight sensor in the passenger seat since I've gone to a set of racing buckets. I know it's not as simple as a resistor and already have a plan for that.

Does anyone know what the color coding for the 3 wires are?

I've already found that the red wire is +12V but I couldn't find anything on the white or brown wire.

I know nothing about this stuff but I may have an extra pad for testing if needed. I cant get mine working correctly after the install Saturday. Heck I cant even get the light off of my dash after the reset. I was so afraid of this! It is killing my OCD lol

I think wstar was going to send you a pad to test with?

I actually just bought a passenger seat out of a wrecked Z34 for cheap. Showed up yesterday and I've already got the mat removed and de-clothed.

http://i1266.photobucket.com/albums/...5D7BC6DDA2.jpg

Managed to expose the terminals tonight. What a PITA that was as this is not a plastic box the circuit board is housed in but instead a solid block of urethane like material. :mad:

Wow.....look at all the sensor points ( I think ) on that thing. This pad is like the VVEL of weight sensors :mad:

I plugged my pad and seatbelt back in without soldering in the 4.7ohm resistors. I thought doing it that way I would not have to.

I believe the sensor points are just piezoresistive based load cells. Assuming I'm right, making a switchable airbag box (on/off) would simple be a matter of replacing the sensor points with 2 resistors. One set of resistors would be "Off" and the other set would be "On".

The 4.7 ohm resistors have to be used to simulate the airbag itself. Without it the system knows the airbag is missing and as a result generates a error.

Y'all may be able to get some info (or at least good hints) from the FSM.

That's where I found that the red wire is +12VDC but it makes no mention of the other 2 wires. :shakes head: I really wish they would just have a full wiring schematic for the entire car.

Does this help at all?

http://i.imgur.com/egNw90r.png
The fact that one of them says "Communication" might mean that it is using some kind of serial or CAN interface.

I soldered the resisitors on and tried to reset my airbag light but im having no luck in doing so. I tried the method given on here several times and still nothing... Any other way in making the stupid flashing dash light go off?

Check the wiring diagrams above the pages where the pinouts were found. And there should be a description of how the system works near the top of the section. I'm kinda busy right now or I'd find the pages for you. If you can't find what you need, I'll search the FSM later.

If there is any kind of electronics near the connector on the sensor, it probably uses CAN or other serial communications.

It looks like the pad is just a bunch of momentary contact "bubble" switches. I'm guessing that there is some electronics near the connector that counts the number of switches made and tells the module (BCM?) that controls the air bag system.
Edit: If I'm right about that, a simulator box would need the electronics. You should be able to fake the bubble switches near the electronics so the box wouldn't have to have a sensor pad crammed in there. OK. Now I really have to go.

Good luck searching

That's something I mentioned before, one wire is doing some communicating back and forth..... I tried measuring resistance but that's not it.
I think the best way to do it is to just go ahead and set all weight sensors to on so the air bag is always on...
Does anyone know or have access to consult to see if this can be turned on or off all the time?

I would rather just have it on all the time as well.

:excited: to see this thread. This exact situation was driving me insane last season, I gave up and just let the damn light blink. Hopefully someone can get to the bottom of this, I ALSO would just like all the airbags to be on all the time.

I believe they make a module an aftermaket module for toyota etc, this might be something to look at as well... see how it works..

It's extremely annoying. My resistors were done properly so it's not that. I tried the reset procedure 10+ times and still NOTHING. All I wanted was nice bucket seats!!!!:ugh2:

Check ur blinking light, it differs by code....

I just let mine blink :p

I would also like to have airbags. If I had the choice of no light but no air bags or air bags and a light, id go with airbags. Would Nissan be able to reset it for me?

I looked through the SR and SRC sections of the 2009 FSM and can't find any details on the "Occupant Classification System Seat Sensor Mat". :(

SRC-15 - SRC-17 shows what the different blinks mean.

SRC-17 tells how to clear errors once a malfunction is fixed - turn the car off and then back on.

SRC-157 (Wiring Diagram - SRS AIR BAG CONTROL SYSTEM)
Occupant Classification System Control Unit terminals 4 and 2 connect to Air Bag Diagnosis Sensor Unit terminals 1 and 26, respectively.
Terminals 4/1 through connector B201(Red)/M117(LG) pin 6.
Terminals 2/26 show no connector
Occupant Classification System Control Unit terminal 5 is ground through connector B202.

Not trying to highjack the thread, but what is the best way to disable the passenger side front airbag. I need to have a child seat in the car for emergencies. So it is crucial for the airbag to be off. I know the car has the automatic sensors, but I notice the light goes on and off when my 20lbs dog gets on it. I just want to make sure the sensor doesnt come back on when I need it to be off! Should I just pull the airbag fuse and call it a day? Also does hte light come on after you plug the fuse back in?

Thanks

cossie, just disconnect the air bag weight sensor and side air bad connector, it will disable it. Later when u want it back, just connect it and do the SRS reset procedure takes few seconds only.

Just an update on this. I'm working on soldering test leads onto the terminals at the moment. Also I have a 12V power supply showing up tomorrow for testing this out. And before anyone criticizes my soldering job, this is the first time I've ever soldered in my life so it's been a learning process.

http://i1266.photobucket.com/albums/...3D28A1029A.jpg

http://i1266.photobucket.com/albums/...3D26497114.jpg

Test leads done and 12V power supply hooked up. Let the testing begin. :tup:

http://i1266.photobucket.com/albums/...AB3A742704.jpg

http://i1266.photobucket.com/albums/...AB4257469C.jpg

http://i1266.photobucket.com/albums/...AB3C779B00.jpg

If you can get this to work I would pay for it! Hopefully there's some way to trick the system to have the airbags on so i can finally install recaros :happydance:

you should be able to read resistance on each point and replicate accordingly. I would guess U need to get X amount of those dots to "turn on" or have same resistance across X amount and it will turn the air bag on.

I never went this far as to tear down the pad but this is a good direction!

My guess is that it counts the number of switches made, but resistance is a good possibility.

Anymore updates Gomer? Awesome work thus far, thanks!

Been super busy the last few weeks getting the car ready for AutoX season. Unfortunately this project has taken a backseat so far. Hopefully I'll be able to get back into it in the next couple weeks.

Wow, good progress gomer, be interesting to see if you can fake it out. I have the weight sensor sitting under the pad of the fake Bride seat in my passenger side, but it has never worked correctly, and pretty much always ends up disabling the airbag.

Design Complaint (against Nissan and whoever else does them like this): Based on reading the manual, what I know about how the system works (stock) is this: that sensor module is supposed to look at the pattern of its inputs (I'm not sure if they're just switches, or each one has a variable pressure value) and classify the seat's contents into one of three categories: 1) Nobody/nothing significant in the seat, airbag off 2) Child in seat, airbag off 3) Adult in seat, airbag on. There's only a single status indicator light, which lights up as to say "Hey the passenger airbag is disabled for child safety", which is option (2) above. That status light is off in both conditions 1 and 3. Given that there's some analog real-world variability to the situation (e.g. an adult with their weight distributed strangely at the edges due to body shape or posture), it's a really bad design flaw that the system doesn't tell you the difference between "no airbag because nobody's there" and "airbag on because an adult's sitting there". Hopefully in pristine stock state those two things are so different that it virtually never gets the distinction wrong, but how would you ever know?

And of course, if you're trying to make it work with another seat (and you know, seats are reasonable aftermarket options even just for comfort...), and all you've got to work with is that indicator light, you *really* have no idea whether it's working right just because the light stayed blacked out when an adult sat down, because again that could mean either of two conditions (and either airbag on for adult or off for "not sensing any real passenger").

I really wish there was option for a simple switch for airbag on/off. I get that they want things to be automatic because people will forget the switch, but the whole thing (not just Nissan's design, but the whole way that airbags work and the safety data on them) smells of poor decisions/design when it all gets this complicated on the tradeoffs. At the very least, they could've made the airbag off light also light up when it detect nobody/nothing, and only have the light turn off when it detects an adult and enables the airbag. At least then you'd know for sure what was going on.

I don't care much anymore, personally, because within a few months I'll be stripping out all the airbag system and doing a cage and harnesses anyways :P

Bump for any progress on this.

The airbag weight sensor is definitely stupid. It doesn't always work. When I put my child seat on it, I have to wiggle it back and forth sometimes in order for it to register. It's scary to know that thing can go off any sec.

This project has gotten pushed to the back burner for now. With the limited "good" driving season up here, I'm making the most of that for the time being.

If anyone has an extra one I can work on it

Anyone have an update?

My light still blinks.....lol

Bought a weight sensor out of a wrecked murano for like $70. Works great, no more light.

^Same pulled the weight sensor out of the passenger seat. It works but like others have mentioned its touchy.

Has anyone tried this?

https://airbag360.com/nissan-370z--p...1018-669-p.asphttps://25.cdn.ekm.net/ekmps/shops/a...=660&h=576&v=1

Yes, I'm using one on my passenger Juke seat and it works perfect

I have a set of factory Recaro seats and I don't have any issues.