FYI, if you "really" dont want to hack up any of the harnesses, you can buy the entire seat harnesses for ~$75 each.

The part numbers for the seat harnesses appear to be:
87019-1EE0A (Passenger seat)
87069-1EE2A (Driver seat)

I dont see where you can buy "just" the weight sensor. It looks like its only available as part of the seat bottom cushion assemblies which are 2000+(!!!!!) each.

I believe if you flip the sensor upside down it leaves the airbag permanently armed.

I don't want to ruin my 40th seats and take the weight sensor out.. Also the recaros im getting don't have removable cushion like the brides so i can't put the weight sensor in anyway.

Is there still no update on how to defeat this?

If I do the resistors on both sides and just leave the weight sensor out will the passenger airbag be armed or disarmed? And will the light on the cluster be on all the time while im driving or will it turn off after the car has been turned on?

I dont think you will ruin the seats, you will just be replacing the metal clips with zip ties which are strong enough since you will use a bunch. If you are anal about the clips, buy a tool to put some new ones back on.

For your recaros, I actually think they will work better than the brides. Reason is the removable cushions in the Brides are two pieces that split in the middle which cause you to put the sensor underneath them. This is the reason why they keep turning the airbag off, it doesn't get enough weight to leave the airbag on since they are underneath the cushion and it thinks everyone is a kid. I would take apart the bottom part of the recaros and do the same thing as your stock seats, which is place the sensor in between the cloth and the cushion. This should give you no problems.

heh? the electrical part is done the reset trick was done but the light still on :/

I guess double check your connections. I didn't have an airbag light come on because I had the battery disconnected until everything was wired up again.

Another note, I have been testing different adults in my seat trying to get this airbag to turn on. It turns off with no problem when it senses weight but it wont turn on when it senses adult weight. I have tried the sensor under the cushion, on top of the cushion, in between two cushions, anyone have luck with this? Doesn't make sense why it wouldn't work as it did with the stock seats unless its because the stock seats are more firm and the sensor is calibrated for that type of pressure.

and that is another thing. I don't have the weight sensor here. It is arriving next week. I think this should clear the issue.

Yeah without weight sensor u get an air bag light.. So far none of us have been able to just leave air bag armed all the time... Seems like the sensor sends some signals back and forth...

I dont want mine to be armed all the time since I have kids. I want it to work just like it did in the stock seat.

Mike I can get mine to turn off by moving it around under the cushion. I found that it works best if it is positioned way back in the seat where the passenger is sitting on the front 1/3 of the sensor pad.

The reason it works in the OEM seats is because it sits on 2" of foam and is fastened to the wire rim around the cushion pad. The sensor acts like a small hammock for your but. That tension activates it. In our racing seats, the hard bottom doesn't allow any stretching of the sensor pad so its hard for it to register unless it is in just the right position.

If the racing seats do not have removable cushions you can always put the sensor pad under it to turn off lights, but you will never have airbag activation in that seat during a collision.

Wait...are you saying that we are fooling our selfs with this? So even with the light off and the whole thing done right there will be no activation when we get a collision?? :icon14:

A couple things I noticed when I was installing my Bride Vios III:

If your anal retentive like me and verify the 4.7 Ohms after it's soldered in place and don't be alarmed when it reads <1 ohm. There's something with the plug that makes it show up this way (wasted 2 resistors because of this).

Looking at the weight sensor pad it looks like a glorified strain gauge (as it stretches it increases resistance). The problem is the module attached to it. I would say with some certainty that if someone was to measure resistance on the traces at the pad to module connection that we'd be able to solve this whole weight sensor issue once and for all. Unfortunately I don't have the kind on money laying around to risk damaging mine. Now if someone wants to give me one to test this with then let me know (can't guarantee it'll come back in one piece though).

If you were 100% on being able to have an always on plug or something by doing this I may donate mine for the cause. I do not want to go thru all this trouble to still have a non working airbag for my wife! Next week the seats go back in so if I have problems I will send it your way if you think an always on option can be made.

For this to happen, the 4.7 Ohm resistor would have to be in parallel with another resistance that's about the Ohm value you are reading on your meter.

If the resistor was connected to the controller when the measurement was taken, there will be "sensing voltage" and/or general solid-state leakage present that can throw off the meter.

Yeah, it would depend on where it was measured and whether it was connected or not.

The measurement was taken with the connector off the car. It was done with the resistor in place and without it.

This is what I had inside working with. (not my picture but close enough)

http://www.the370z.com/members/equin...t-resistor.jpg

Wasn't trying to start a argument just trying to point out a nuance of doing this DIY.

Yeah I wouldn't feel comfortable taking your's unless I knew I could actually make it work. Think I just need to find one off a Z that's been totaled and sitting in the salvage yard.

Not arguing (at least I wasn't). Just throwing around some ideas, trying to figure out why you're not reading 4.7 ohms.

PM me your address I can pull mine out and send it ... sold my driver side seat but the pax side is just sitting in the garage collecting dust. Would take me a day or so to get it out of there (the pad) and mail it. Would I get it back ?

The plan would be to remove the white and black fabric off both sides of the pad to be able to follow the circuit traces. Would also need to scrub off the plastic covering off the traces at various spots to be able to take readings.

Assuming I'm right about the way the sensor is designed I would envision a small box containing the original control module, additional wiring, and a switch to enable/disable the airbag.

As far as getting it back: if it works then absolutely, if I can't figure it out then I'd still get it back to you the only thing would be that the fabric on both sides would be removed and the mat would have some exposed circuit traces on it.

Let me know if you're still interested.

Also just came across this: BMW & MB SRS Emulator. Obviously it's not spec'ed for our cars but for $20 it might be interesting to give it a shot and see what happens.

I believe that the sensor pad and box relays info before and after maybe, I don't think it's just a matter of impedance.. Buy hope it is... I know someone that measure it w no success

What I really want to do is eliminate the mat and just keep the little box with some extra wire and switch attached to it.

What would be really nice to find is one of these weight sensor emulators that exist for a lot of other cars out there that would work for us on the Z34.

Also just found this on a Mini forum and surprisingly their sensor mat module looks very similar to ours. Mini weight sensor

Finally got my hands on a sensor mat. In case anyone cares this is what it looks like with the fabric removed.

Also does anyone know which wire is which going to this thing. I found that the red wire is is +12V in the service manual but that's it. That leaves me with a white (slight pinkish hue to it) and a brown. I'm guessing that the white is the common/gnd but would rather know for sure so I don't short this thing out.

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

Hope someone will replay today... but will a 2.2 Ohm 1/2 watt resistor work too? I'm doing the install today and found out about the airbag sit. today as well. I don't have time to wait for a package :/

4.7 ohm 1/2 W is what you need. Hit up RadioShack and find the combination package with multiple resistors inside. I believe I saw one the other day which contained the 4.7 ohm resistor we need.

4.7 ohm; not 4.7k.

Just an update on how my aftermarket seats are set up.

Driver and passenger each have a resistor for the SRS wiring. Seatbelt sensors were also reconnected. The concern people have is the weight sensor, which definitely does involve a daunting task of tearing up the OEM seat to retrieve it. When I finally did remove it and install it underneath my Sparco seat, it did not register even with my weight (~190 lb) and the airbag remained off. When I adjusted the sensor like one poster said earlier in this thread, the sensor worked without issue. The remedy was to (at least for me) flip the sensor white side up (contrary to the factory black side up), and relocated the sensor toward the rear of the seat, so that a passenger would sit on approximately 1/3 frontal portion of the sensor, hopefully triggering it.

I braced myself up while sitting and lifted off a seat slightly, and the sensor indicated that the airbag was off, to test lighter weight function.

If you're looking into aftermarket seats, there is hope.

i've bought 2 different brands of 4.7 ohm resistors and 1/2 watt with 5% error and still having trouble getting the airbag light reset. I've confirmed i've done the resetting process correctly when putting the stock seat in. Any advise?

Is the passenger seat weight sensor plugged in? If not, you will not be able to reset the system.

I've seen reports of people having to try reset procedures (not just the air bags) quite a few times before it "takes." Your timing has to be damn near perfect.

Double-check your wiring. If the resistor leads are not making good contact with the connector, it can mess things up due to higher than expected resistance.

Thanks for helping. I only have driver's Seat replaced. So far I've tried 20+ times doing the reset (over 4 different resistors many tries). Perhaps tonight I will switch back to stock seats to see if it's the resetting part i'm doing wrong. In addition, i'll also check to see what the resistor is really reading.

Update please!

is the weight sensor transfer required for a Driver's seat swap?

No this is for the passenger side airbag only. You will get a airbag light from the missing side air bag though.

:iagree:

Add the resistor and the missing airbag won't cause a light.

Question, do we need to plug in the seat belt sensor at all? Can I run w/o it plugged in?

When I installed my seats, I removed the seat belt clip from stock seats to move to my new seat rails/brackets. I cut the wire that was running to the seat belt clip. I have plenty of room left in case I need to rewire it for any reason.

You can run without it being plug in you will just have the seatbelt light on in your dash. Good thing the Z do not make any chiming sound.

Perfect, thanks. I ordered some resistors and I should hopefully tackle it this weekend.


Tapatalk

what gauge are those wires?

Has anyone spent any significant time on the weight sensor resistance? I would have no problem with the airbag being on the entire time.

Does anyone have the Radio Shack part number for the resistor, went there yesterday and was given(4.7K) which I've now learned is wrong. Thanks:tiphat:

I didn't see any 4.7 ohm resistors on RS's web site but they do have 10-ohm 1W 5% Metal-Oxide Film Resistor (2-Pack) | RadioShack.com - two of those in parallel will give you 5 ohms which may (or may not) be close enough.