Airbag deactivation and isofix

[Adamfoster]

Hi all, I’m new around here, but have had the wife’s Z4 for almost a year.
It hasn’t been without its issues, but slowly getting there now.
My wife is expecting our first baby in June and as a result our last chance to keep the car is to retrofit the airbag disable feature. I’ve managed to source the switch for the dash and light for the centre console and being an 04 I know the plugs are already there. Threads and info on this subject seem scarce.
The questions I have are

1. Will I need to have it reprogrammed to tell the car it has the function? If so, is there anyone in or near South Nottinghamshire who is able to do it

2. I’d like to add isofix if I can find it. Is it just a case of swap the rear cross bar on the seat base and where might I find one?

Thanks all

 

[yipikayee]

Hi mate, congrats on your firstborn
I was looking at it myslef, did you check if the wiring is actually there? I did and im missing wire in center console, i have only one behind air vent. I don't think it need to be programmed, just plug n play i was told.

 

[pr117]

I was just studying this airbag thing. The co-driver sensor is supposed to be smart enough to get the weight of codriver (or just the child seat) and control the airbag depending on that. This was an "experimental" system that BMW used on Z4 and i think dumped later on. Maybe it was just on cars that came with isofix seat.. I hope there is someone to confirm if i got it wrong or right. I will check again if INPA has some different values for that.

 

[Pops3.0]

Congrats on a lifetime of toil, hardship & the best thing that'll ever happen to you
Very interested in this myself, although my wife says I'm not taking my grandson out. I think my daughter will allow it though . I'll be checking for wires this weekend so any further info would be gratefully received.

 

[Adamfoster]

I was looking at it myslef, did you check if the wiring is actually there? I did and im missing wire in center console, i have only one behind air vent. I don't think it need to be programmed, just plug n play i was told.

Yep. Wiring is there up until at least 2005 I believe. Found mine hiding under the carpet on the LHS kind of between the ash tray and Drive selector surround. (Mines an auto)

 

[Adamfoster]

The co-driver sensor is supposed to be smart enough to get the weight of codriver (or just the child seat) and control the airbag depending on that. This was an "experimental" system that BMW used on Z4 and i think dumped later on.

I did find a mention of this, but I think that was only on US cars. UK ones definitely have the switch and light. Mine should be delivered this week.

 

[pr117]

This is one place that mentions it..
https://www.bimmerfest.com/threads/z4-airbag-light-come-on-all-of-a-sudden.271499/post-9061597

But i have read it somewhere else also.
Though, seatbelts and airbags are serious business. They can save or take lives. So anything you do be 110% sure about it!

 

[Adamfoster]

I'll be checking for wires this weekend so any further info would be gratefully received.

If you pop the passenger air vent out there should be a white plug somewhere there (mine was obvious to see). If you pop the ashtray out and maybe the gear lever gator there should be a blue plug with 2 wires on the left of the tunnel (this was more tricky on mine as I found the wire but had to fish around under the carpet to find it).

I’m going to have to have it plugged in anyway as I pulled the passenger seat out the other day to dry the floor out forgetting to disconnect the battery and now the airbag light is on.

Thanks for the congratulations everyone.

 

[yipikayee]

Yep. Wiring is there up until at least 2005 I believe. Found mine hiding under the carpet on the LHS kind of between the ash tray and Drive selector surround. (Mines an auto)

I was wondering if i could do with only switch mounted, without having airbag light connected.
In theory, if i connect the switch airbag should be off - light just gives information. My airbag light is on since i bought the car and was thinking that maybe if i connect the switch and turn the bag off, i could connect OBD and check to be 100% sure if its actually working.

 

[Beefy]

My car has iso fix, airbag switch and light I always assumed it was standard in all z4’s... something else I’ve noticed is if I sit anything heavier than a face mask on the passenger seat it brings the airbag light on, but if someone sits in the seat it doesn’t come on... I always thought it was some sort of fault, but from what I’ve read above I guess it’s meant to do that.

 

[Adamfoster]

My car has iso fix, airbag switch and light I always assumed it was standard in all z4’s... something else I’ve noticed is if I sit anything heavier than a face mask on the passenger seat it brings the airbag light on, but if someone sits in the seat it doesn’t come on... I always thought it was some sort of fault, but from what I’ve read above I guess it’s meant to do that.

I have read something about there being a weight sensor in there.

 

[Adamfoster]

Yep. Wiring is there up until at least 2005 I believe. Found mine hiding under the carpet on the LHS kind of between the ash tray and Drive selector surround. (Mines an auto)

I was wondering if i could do with only switch mounted, without having airbag light connected.
In theory, if i connect the switch airbag should be off - light just gives information. My airbag light is on since i bought the car and was thinking that maybe if i connect the switch and turn the bag off, i could connect OBD and check to be 100% sure if its actually working.

I’m not 100% sure. The power comes from the fuse, through the bulb and into the controller, so the controller might check the load on that circuit when it does its initial safety checks on startup.