Airbags maintain, update or disable?
10-18-2016, 10:22 AM
#16
As mentioned before, the system runs a check every time the car is started and any faults will result in the airbag light NOT going out on the dash. As for Chris R's pothole experience, my understanding is that the bag(s) deploy when there is a noted deceleration of the car- and depending on the unit, it has to be sensed by 2 or more of the sensors in order to fire. My assumption is the the pothole was significant enough to stop forward progress of the car and hence, bang. Condolences to Chris R and I'm glad no one was seriously hurt but it seems like the airbag causes a lot of collateral damage to the car. I'm not taking the airbags out of my 91 964 but it also doesn't see the track. I read that Porsche advises airbags be checked at intervals : when the car is 4 yrs old, when the car is 8 yrs old and then every 2 years thereafter. Honestly, I've no idea if my shop has been checking for airbag system faults . I should find out.
10-18-2016, 04:03 PM
#18
Three Wheelin'
I have a big worry about a 25 year old airbag.....the recent Takata issues raise very worrisome thoughts on how the older Porsche systems might perform (I don't believe Takata supplied inflators to Porsche). Even if the computer check says they are working it doesn't nessecarily mean you aren't in danger. Same issues might play a role if inflators get any corrosion and break apart upon airbag deployment.....the pieces will go through you like a knife through butter. In Takata's case they discovered that changing certain materials in inflator prolongs the chances of corrosion taking place but those problem airbags are only 10-12 years old vs double that for our 964 airbags!!!?? Scary thought and one that's made me consider removing my 964 airbags multiple times but I still haven't touched them. If you do remove make sure you don't store with airbag facing down lol!
01-18-2019, 01:31 AM
#19
Three Wheelin'
Spyerx, an airbag sensor is in effect a programed accelerometer, bumping and shaking will not set off the airbags. In the U S, airbag deployment requires a rapid deceleration before a signal is sent to the airbag’s ECU, this little computer uses an algorithm to also check wheel speed and other sensors to decide if an airbag inflation is required. A “minor off track” as you have stated, will not set off your bags. Millions of trucks etc. bump and bash around off-road without setting off the airbags. The interiors of all the crucial airbag components are sealed in a glass ceramic material to keep them fresh and moisture free. Although nothing is foolproof, note the Takata bag recall. These units deploy as required, but may also toss some metal shards from the bag’s outer case into your face.
The red car in the picture (several posts above) has a broken bumper cover from hitting some of those small springy trees that would brought it to a sudden stop. More telling is the completely popped out windshield, this must have been installed by the worlds most incompetent glass shop, or by some well meaning but clueless amateur tinkerers. This should never happen in an accident, rollover etc. it prevents the passenger airbag from attaining the correct shape, allows a child or other occupant to be ejected and reduces the structural integrity of the car.
The red car in the picture (several posts above) has a broken bumper cover from hitting some of those small springy trees that would brought it to a sudden stop. More telling is the completely popped out windshield, this must have been installed by the worlds most incompetent glass shop, or by some well meaning but clueless amateur tinkerers. This should never happen in an accident, rollover etc. it prevents the passenger airbag from attaining the correct shape, allows a child or other occupant to be ejected and reduces the structural integrity of the car.
They didn't bond windshields in until the 993.
01-18-2019, 09:08 AM
#20
Rennlist Member
01-18-2019, 01:11 PM
#21
Technical Guru
Rennlist Member
Rennlist Member
The 964 windshield glass is bonded to the seal and the seal is bonded to the frame. The change for the 993 was to bond the glass directly to the metal. You can see in the photos above that the adhesive was improperly applied to the frame when the replacement windshield was installed.
01-01-2021, 07:07 PM
#22
Three Wheelin'
anyone have any info re: new airbags or a way to refresh? I do worry now that my car is 30 years old and would like to maintain safety. would be happy to buy new units if they are available / sold.
01-01-2021, 10:47 PM
#23
Burning Brakes
Mercedes used to have airbag expiration dates on the left door jamb. Subsequent testing on their part stated that replacement is not required as they’re holding up with age.
