Disable Xantia S1 passenger airbag ?

[Mandrake]

Hi All,

My 1997 Series 1 Xantia V6 has a passenger airbag however there is no key switch in the centre console to disable it, and a warning sticker near the door not to use car seats in the passenger seat.

Now that we have a two month old it occurs to me that while his car seat currently always goes in the rear on the left hand side, there might be occasions where he would need to go in the front seat, for example if the seats were down for load carrying. Because I can't turn off the air bag I can't do this.

I know that some Xantia's had a key switch near the height control lever to disable the passenger air bag for use with car seats, is there any way to safely retrofit this ? And why have none of the Xantia's I've seen ever had this fitted ? (Is it quite rare ?) The pictures I've seen put it in front of the height control lever where the sport mode button resides, so clearly that location is not available to fit it on this car.

[Stickyfinger]

I have an AirBag switch hanging on the wall (with a key) from the Green Goblin.....yours if needed. Others maybe able to tell you if it can be fitted but it looks like a simple switch to me, I would be worried about switching when live so I would not say if you can or cannot use it.
.

[RichardW]

There was a switch next to the height adjuster on my MK2 (non hydractive); I had a MK1 hydractive with pass airbag; but I don't recall if there was a switch or where....no recourse to use it in those days!

[CitroJim]

This is tricky... You can't just disconnect it as that will bring on the airbag warning light.

I believe (must be confirmed) that if you use a 2.2 ohm resistor in place of the airbag then the ECU will be happy. Therefore a changeover switch to select between airbag and resistor may do the job...

[Mandrake]

I wonder how the original switch was wired though Jim ? Perhaps it just removed power to the ECU for the passenger bag ? Or maybe it had a special disable control line. I'd need to see a wiring diagram of a model that did have the switch fitted to know.

[CitroJim]

Simon, I can possibly find a diagram of an S2 to see how the airbag control works... Knowing where the switch is and where the ECU is, I fear the switch may just connect to the ECU under the coin tray rather to the airbag itself... Having the switch down there too would have made the wiring very easy...

[spider]

I **think** (I'd have to check this) models that have the switch fitted (applies to Peugeot too) have a slightly different SRS ECU fitted. The reason being I'm reasonably sure the switch is connected to the ECU not to the 'line' itself as Jim has said. In other words there are a few extra wires on models with "disable" available.

The resistance value quoted appears about correct however.

[BX]

The disable switch is wired straight to the ecu. The ecu illuminates a warning on the dash when the airbag is disabled.
However I can confirm that the 2.2 ohm resistor will work. You can use a double pole change over switch DPDT. Use one pole to switch one leg between the airbag and the resistor. Use the other pole of the switch to activate a warning lamp so the driver is aware that the airbag is disabled.
The other leg of the resistor and the other leg of the airbag can remain permanently connected together and to the wiring back to the ecu

[CitroJim]

BX, that's excellent and a very good idea indeed to include a warning light in the scheme... It only needs to be a small one and I'd say put it very close to or with the switch.... A bit of ingenuity could see a standard dash switch used for the purpose in one of the spare positions and a LED used within the switch to provide the warning... I'd go for a blue LED...

[spider]

I do not want to put any dampener on this, but it may be prudent to tell your insurance people about this 'modification' even though its in the interests of safety...

[CitroJim]

Good point well made Andy...

[Hell Razor5543]

The other issue is to make sure the airbag system gets power cleanly as the switch is used. Don't want it going off when the switch is used.

[RichardW]

By the look of it on service.citroen no Mk1 cars had a disable switch.

[CitroJim]

By the look of it on service.citroen no Mk1 cars had a disable switch.

No, just a disabled glovebox

The other issue is to make sure the airbag system gets power cleanly as the switch is used. Don't want it going off when the switch is used.

Good point James. I'd only ever operate such a switch when the ignition has been off for at least 10 minutes to be sure... It should be OK but.... Better safe than sorry...

[spider]

By the look of it on service.citroen no Mk1 cars had a disable switch.

I think (generally) the option to do this on PSA cars started to appear about 1998. Certainly things like later 106's / Saxo's / 306's etc had them but not the earlier ones.