Airbag light

tezmanian · 02-17-2009, 04:28 PM

Comes on at startup, goes out after 3-5 minutes, may come on intermittently. Airbag reset tool did not correct. No steeering wheel removal or replacement; no seat modifications; no seat occupants except driver. Any thoughts on where/how to start troubleshooting? ('95 318i). Thanks.

'95 E34 530i (WBAEHE2328SGE93854), '03 540iA, '95 318i (4USCC7328SLA03012)

Manolito · 02-17-2009, 08:54 PM

That is odd because in my experience, the airbag light tends to stay lit until it is cleared, even if there is nothing wrong. Because it is behaving oddly, I would not trust any code it gave me. Just for giggles, however, did it give you a code when you tried to reset it?

All I can think of is to track down every ground and clean it and unplug and plug every connector to freshen connections. That will mean unbolting and tilting back your front seats to get to the occupant sensor, seat belt buckles, and tensioners.

tezmanian · 02-18-2009, 05:28 AM

Thanks for quick response. Don't have a code reader tool, just cheaper reset tool, so I do not have any codes to report. Will the stomp test reveal airbag codes?

Manolito · 02-18-2009, 05:38 AM

I have not owned a car on which the stomp test would pull codes, but I am pretty sure that test gives you only engine computer codes. The airbag system is an independent system, though it uses the same underhood connector for diagnostics.

Tim Polzin · 02-18-2009, 07:01 AM

Quote:

Originally Posted by tezmanian

Thanks for quick response. Don't have a code reader tool, just cheaper reset tool, so I do not have any codes to report. Will the stomp test reveal airbag codes?

The reset tool you have is only for resetting the oil/inspection light. The SRS system uses a special tool that fits on the same connector.

The 3-5 minute light at start is typical on a system that has shown a fault. My understanding is that the air bags MAY still work. I've never seen the SRS light come on when driving the car, only on startup.

My 318i shows a periodic faulty passenger seatbelt receiver and is usually triggered when a passenger moves his seat when the car is operating. When I reset mine, it usually is fine for a long time (up to a year).

Find someone with the reader and check the codes. Try resetting it and see if it stays off.

Tim

tezmanian · 02-18-2009, 07:59 AM

Thanks. The reset tool I have is an AST 5413A, and it resets inspection/oil and SRS...but doesn't read codes. That's what I get for being cheap. I bought it specifically for the SRS when ignition switch was replaced in my 95 530 which required steering wheel removal and subsequent SRS system reset to extinguish light, so I know it works. I will try seat occupant and seatbelt sensor connection cleanup and reset again, and I will report results.

coolbear1 · 02-18-2009, 03:38 PM

My car is an older one, but the SRS light has acted up over the years and I have had success with disconecting the battery for an hour or so. I seems to clear it up. I know the SRS has an internal battery and some year models take longer for the back up to discharge. I don't know about yours, but it may be worth a try, if you have not done so already.

racinteach · 05:41 AM

Hello, am new to the forum, so I hope I am posting in the right location..I hate starting new threads when one is already alive.

92 325i sedan. replaced cylinder lock, put air bag back on..had battery off the car for many days since it was dead and the light still stays on...my question is, is there a specific way the airbag on the steering wheel plugs in? in other words, the orientation of the plug? am wondering if that would cause the light to come on...thanks

SCOTITUDE · 11:05 PM

Tez,
the slip ring inside the steering wheel is starting to go. Hear any clicking or crunching when you turn the wheel? Easy repair. The ring is the connection from your airbag to the wiring harness. lets you spin the wheel without spinning the wire. They go bad and lose the connectivity signal causing the SRS light to come on. First intermittently, then as it deteriorates it'll stay on. If you have any kind of code reader, when the light comes on you should get a low or no voltage message. i got a used one on ebay for $50. 1/2 hr install.

pelican has them new, Product Information: 32-34-1-162-804-M9

tezmanian · 02-23-2009, 05:05 PM

For racinteach--I think you will need to use a reset tool/reader to reset he light. That's the only way I was able to turn of the SRS light on my 95 530 when the ignition cylinder was replaced--that's why I bought the reset tool; it was cheaper tha na trip to the dealer. If you live anywhere near Massachusetts/NH I will happily lend you mine.

tezmanian · 02-23-2009, 05:08 PM

My problem mostly solved today--thanks to all who offered help. Peake SRS reader says it's driver side seat belt sensor. Peake reset light so it's off for now. Looking for the seatbelt receptacle for manual seats--new one is too expensive for this old car ($190!), so am looking for used.
For Scotitude, I can hear those crunching sounds, too, so that may be a project for another day.

Manolito · 02-23-2009, 08:44 PM

Pelican sells the seat belt buckles. They are hard to find in a junk yard because almost any accident triggers the tensioner, which trashes the buckle.

Don't get in a hurry to buy a new buckle. Once those buckles get used a few times, just jambing the tab into them at an odd angle will set the SRS light.

On my original e36, I had two new driver seat belt buckles installed during my four year initial warranty. When the SRS light came on again right after the warranty expired, I realized that there may not be all that much wrong with the buckle, so I just reset the light. It was fine.

Also any electrical irregularities, such as spikes or dips in voltage, can set the SRS light. An old battery or poor ground connections can be the culprit.

racinteach · 03-01-2009, 06:40 AM

Ok well anyone is the Los Angeles area have one of them reseting tools..Ill buy one eventually, but $$ is non existant at the moment..new Baby is on his way..this is the reason I got this car to begin with..still need rear shocks and to find a way to seal up my AC leak..Thanks..

brothersinc1 · 03-06-2009, 04:21 AM

96 328i 105,000 - Same exact problem here. Light goes off after 3 to 5 minutes. Annoying but not enough to tear into it yet. I will wait until the message console starts harranging - which will push me over the edge.