Passenger Seat Occupancy Bypass circuit DIY

Kamz

///Member
Hi Guys...

I have been wondering why my airbag Light comes on and off when i have a passenger in my vehicle, i did some research and found that the sensor on the passenger seat is gone :-( A good DIY for the bypass of the occupancy sensor was found thanks to GOOGLE... The circuit makes the ECU think there is always a passenger in the seat , hense in case of an accident both front airbags will deploy...

Here is a pic of the Circuit, i have made and installed it, works 100%..
Even have some spare resistors and diodes if anyone wants to fetch to make their own... it practically R2 for the whole circuit...




If you look under your passenger seat towards the back , you will find two wires coming out of a black BOX, a white and blue wire, all you gotta do is cut the two wires and then rewires as per the circuit diagram...
 

Tumo

New member
but that means that the passenger air bag will not deploy if you are in an accident?
 

Kamz

///Member
Tumo said:
but that means that the passenger air bag will not deploy if you are in an accident?


The circuit provided tricks the ECU to think the seat is always occupied, therefore the airbag will always deploy regardless if there is someone there or not...
 

moranor@axis

///Member
Official Advertiser
out of interest how much will the stealers charge the fix this? if its not that much... LOL it may be better to get it fixed because now if you have an accident and it is not written off you will have to replace two air bags... but im guessing even if you have to replace the air bag it would still end up cheaper
 

Kamz

///Member
Scheww firstly the stealers are unable to give me a price even though i have told the issue and pre-diagnosed... LOL...

They want to me drop the car off , pay the fee for it to be checked up and the quote me so.... ya not really interested in that. I have done allot of goggling :) and apparently its quiet abit!!! Ebay even sells these circuits for about 1K...
 

zaleonardz

Well-known member
Well, I have this problem on my Golf 5.

Stealers wanted to charge about 5k including replacing the wiring plugs under the seat which is a "known problem for failure"

I was also pretty much fsck that....

If they replace the seat sensor, thats seat out, covers off + sensor + back.

So like 3 hours labour at 500 plus the sensor which should be about a left testicle... and your sorted :)
 

Kamz

///Member
zaleonardz said:
Well, I have this problem on my Golf 5.

Stealers wanted to charge about 5k including replacing the wiring plugs under the seat which is a "known problem for failure"

I was also pretty much fsck that....

If they replace the seat sensor, thats seat out, covers off + sensor + back.

So like 3 hours labour at 500 plus the sensor which should be about a left testicle... and your sorted :)

True , its common with the BMWs as well... O well guess there is a easy way out there to fix.. the only reason for the sensor being there is to save on repair costs... the way i look at it , thats the reason why i pay insurance!!!
 

rick540

///Member
If the airbag is dual stage can't it deply at full force and snap someones neck?

I read that some of these sensors sense weight as well for multi stage airbags.

I replaced the pad in my E39 passenger seat, cost me R950 from BMW and fitted it myself in an hour.

The next person that leans on the seat with their elbow or knee on it will get shot in the ass as it's this that breaks the sensor pads.
 

Sankekur

///Member
Did the e46 have multi-stage airbags, from what I read in the e46 the sensor only detects occupancy not weight.
 

Kamz

///Member
Sankekur said:
Did the e46 have multi-stage airbags, from what I read in the e46 the sensor only detects occupancy not weight.

Thats true... exactly what i have came across during my google research lol
 

Hellas

///Member
How does this sensor/button look like? And where/how is it mounted? I've got two wires buttons in my SUV that I don't know the function of.

They came from under the center console and are normally open (click button) switches.

There are two, but the drivers occupancy works fine as the alarm still sounds when you don't wear your belt. Not sure yet is this functionality is connected to the seatbelt buckle holder.
 

Sankekur

///Member
From what I hear the sensor basically to pieces of metal (foil) with some foam rubber with holes cut in it between the two pieces of metal, something like this, might be a bit more complicated than this but from what rick said it seems like it is something that breaks or gets damaged easily.
 

applehero

///Member
Kamz said:
Tumo said:
but that means that the passenger air bag will not deploy if you are in an accident?


The circuit provided tricks the ECU to think the seat is always occupied, therefore the airbag will always deploy regardless if there is someone there or not...

If the ecu always thinks there's someone in the seat, won't it leave the seatbelt warning light on as the seatbelt isn't clipped in on the passenger side? :dunno:
 

Sankekur

///Member
Not sure but I think the seatbelt warning goes off after a few seconds even if you haven't fastened your seat belt, well on the e46 at least, but I will have to check.
 
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