Retrofitting Passenger Airbag Switch

[Tre303]

I bought my Z4 roadster in 2007 and didn't pick the passenger airbag de-activation switch option at the time.

Now I have a baby that I need to drive to day-care in the mornings, except that I can't unless I manage to de-activate the passenger airbag. Is it possible to retrofit the switch, and if not is there any other way to solve this problem?

Thanks.

[TH3R4POR]

I thought there legally had to be a way of disabling passenger airbags, I can't imagine this was a cost option?

have you looked on the far left edge of the dash with the passenger door open?

[Andy]

Yeah it was an option, and there's a retrofit kit as a part number.

Lemme look...

[AlanJ]

Sorry if I’m stating the obvious but firstly you cannot put a forward facing infant carrier in the front seat of a car equipped with a passenger airbag – certainly illegal in the UK and not advised elsewhere. Many family saloons come equipped with the ability to disable the airbag either through a key switch or other switchable device. In the Z4 this was an option and the control switch placed adjacent to the gear lever. The earlier model options showed it on the list as the ‘ISOFIX child seat system’ which included the switch to deactivate the airbag. If I’m not mistaken this is now fitted on all BMW cars as standard and is no longer the option it was back in 2007.

As for retrofit – the activation of the airbag is triggered by a number of sensors all of which ultimately trigger an electric current to activate the airbag. Find a way of interrupting this current with a switch and then you can obviously disable it. However in the original system this is linked to the dash ‘airbag’ warning display which lights up when you switch the ignition on and extinguishes when you start up confirming all is well. I fear that by merely interrupting the passenger activation circuit with a switch you will also cause the system to detect a fault and this will in turn light up the dash display continuously and may unwittingly hide a fault in the drivers system.

If you attempt to put an isolating switch in the passenger airbag activation circuit then as a minimum disconnect the battery and allow 20/30 minutes for any latent current to discharge from the electrical system. I personally think this is an ambitous modification but others may have a solution.

Before I attempted any of this I would call into the dealers to see if a retrofit is possible.

[Andy]

http://bmwfans.info/parts/catalog/E85/R ... 1%C2%A0229

Part number: 61 31 0 411 229

[PawnSacrifice]

To add to the above, as Andy did the hard part...
http://www.cooper-bmw-parts.co.uk/index ... virtuemart

Thought it was a lot more £.

[AlanJ]

http://bmwfans.info/parts/catalog/E85/R ... 1%C2%A0229

Part number: 61 31 0 411 229

Steady with the drill...........

[m44rrt]

Like many others my passenger airbag sensor has a mind of its own - it comes on after half an hour with a passenger in the seat!
A retro-fit could save my indy doing a reset after every passenger trip
But thats kinda when I need the airbag to be available
Ongoing condundrum in another thread....

[cj10jeeper]

AlanJ to add to your post my understanding is that if you interupt the airbag system (cut wires, etc.) and the dash light comes on then the entire system is disabled until it is corrected and reset. BMW service told me this when I had a faulty passenger side door harness, so it could be a lie, but the logic was that they could not risk the liability of having a false deployment caused by a fault in the system.

[sk93]

slightly off-topic, but how much does it cost at a dealer to clear a faulty airbag light, if you know for certain what caused it?

[AlanJ]

AlanJ to add to your post my understanding is that if you interupt the airbag system (cut wires, etc.) and the dash light comes on then the entire system is disabled until it is corrected and reset. BMW service told me this when I had a faulty passenger side door harness, so it could be a lie, but the logic was that they could not risk the liability of having a false deployment caused by a fault in the system.

Sounds about right. A warning light would discharge their liability........ in the event you chose to drive and were involved in an accident. One would assume the retrofit wiring kit takes account of these issues but logic would suggest the whole rewire process with the kit would need coding in as in effect you a merely isolating the bag from any vehicle input in much the same way as cutting into the wiring harness. Doesn't sound as simple as 'plug and play'.

[cj10jeeper]

sk93 - around the £40 to £50 mark as they charge for the time of hooking it up to their system. sadly during the hundred mods I did I activated it once and then at a later date a faulty harness triggered it. Autoligic units can clear them but my local Indy can't

AlanJ - I'm sure the effect is to sever a signal wire, but the control unit will surely need programming to differentiate between the switch on/off and a fault in the circuit

Airbags are on of the few things I won't mess with other than removing them to work on components - door trim, steering wheel, etc.

[AlanJ]

Just had a look at the retrofi kit - there's actually 2 parts to this: the wiring and switch £35 (61310411229) and the side panel lock £72 (51168268260) which will need to be matched/coded (BMW speak) to the ignition key. In view of the safety aspects which cj10jeeper quite rightly points out this may be one occasion where it's best left to the BMW dealer (and you've got someone to blame when it all goes wrong!)

So parts £107, labour £70 plus (yes, a conservative estimate), coding if required £70...... so perhaps a £250 retrofit!

[Andy]

+1 to CJ's comments - except i was under the impression the driver's side one would always activate, even in a warning light situation.

[AlanJ]

+1 to CJ's comments - except i was under the impression the driver's side one would always activate, even in a warning light situation.

I suppose it depends what fault the light is indicationg and as it's just and indication of something wrong as it could be a failure of the bag itself which triggers the warning.