Audi A4 Airbag: Rear Crash Sensor Ohms Value

Hello,

Can anyone tell me what the resistance value should be for the igniter coil of the rear center seatbelt pretensioner?

Audi A4 Avant, 12/98 (model year 99)

Hi, I can't directly help you, but I can tell you that the igniter for the side airbags of a Golf 3 has a resistance of 3.1 Ohms. At least, that's the value of the replacement resistor used when decommissioning them. I suspect that other igniters will have a similar resistance.

Has anyone ever directly measured the A4 seatbelt pretensioner? I doubt it, because from an ESD (Electrostatic Discharge) perspective, it's not very smart if you want to avoid misfires of a different kind.

Regards,
Sure, here's the translation:

"Guste" is a German word that means "gust" or "gust of wind." It can also be used to describe a sudden burst of something, such as laughter or anger.

Perhaps it would be helpful to approach the problem from a different angle and investigate what's wrong with the seatbelt pretensioner.

...in some cases, it might also be possible to disable the component much more easily by reprogramming the control unit. However, this would likely invalidate the vehicle's approval, unless the modification is officially documented with the TÜV (German technical inspection authority).

@ Guste, thanks, but I've already tried that with the 3-4 Ohm setting, but the error message still appears.
I suspect that the seatbelt pretensioner in this vehicle has different settings than a standard airbag.
'The wiring to the ignition coil in my car has a very high resistance (50 kOhms), and I won't be installing anything new in this old car, especially since there's no one sitting in the back.'

Regarding measurements - it's perfectly safe as long as you're properly grounded, because these ignition coils require a certain amount of power to discharge. Modern digital multimeters measure in microamps, which is a million times less than the required ignition current.

@Sebastian: It's a myth that the BE (Basic Income) disappears as soon as you turn a screw somewhere.

The modification must be legally relevant in some way, but a seatbelt pretensioner doesn't fall into that category. I could remove the entire bench seat and still have a valid vehicle registration.

'As far as I know, it's not possible to recode it. And I would much rather spend hours measuring spark plugs than experimenting with the configuration of the engine control unit.'

garth.brooks wrote:

@Sebastian: It's a myth that the BE (Bundesenergie) disappears as soon as you turn a screw somewhere. The change must somehow be legally relevant, but the seatbelt pretensioner is not.

Seatbelt pretensioners are part of the airbag system, and if you trust the specifications and documentation from VW/Audi, you have to accept that. Generally, the vehicle manufacturer states that deactivating seatbelt pretensioners is not permitted, except for modifications for people with disabilities, where it can be deactivated via software - so no unauthorized modifications.

Furthermore, VW/Audi continues to state in the guidelines that documentation and registration must be carried out by organizations such as DEKRA or TÜV. Finally, the modification must also be registered with the manufacturer.

Since working on these safety systems requires specific expertise, and based on your answers, I am inclined to decline your request... When I write that the deactivation should be possible through software on your Audi, you can assume that I am correct - no offense, but according to your understanding, the vehicle registration should not be affected.

Hello, I certainly don't plan to ever decommission any safety-critical component.
If I wanted to do it the way you suggest, I would connect it using my adjustable potentiometer and try different settings until it accepts the replacement resistor.
Assuming we don't want a completely anomalous and skewed value that deviates from the expected range!
Sure, here is the translation of the text from German to English:

"edit."

This is a simple command that tells the user to edit the text. It is often used in online forums or chat rooms.
How about using different potentiometers or spindle trimmers, as long as the load on them isn't too high.

@ garth.brooks: Audi A4 Avant, manufactured in 12/98 (model year 99).
AFAIK, the rear bench seat in the B5 model was never equipped with seatbelt pretensioners.
Otherwise, the values are typically between 2.5 and 3 ohms.
Best regards,
sausewind