Airbag light came on.....

abcxyz · 07-08-2008, 08:53 AM

Hi~ I have a 1998 328is, and two days ago, the red airbag light came on and it stays lit. The manual says that if it doesn't turn off, then something might be wrong with the airbag system.

Is there anyway to check it manually, and how to know which of the 4 (i think there's 4) airbags might be faulty. How do the mechanics check that?

If I just ignore it, it doesn't affect anything right? Like the airbag won't blow unexpectedly one day will it? Thanks for any input...

Yurick · 07-08-2008, 02:24 PM

You would have to connect to a scanner to get additional diagnostics info.

Manolito · 07-09-2008, 05:36 AM

The airbag won't blow unexpectedly (probably not anyway)
and it will likely still work if you get in a crash, from what I have read.

This light monitors a dozen different components, such as the belt buckles, the tensionioners under the front seats, the connection to the bag, the control module, and so forth.

When the seatbelt light comes on in an e36, there is usually nothing at all wrong. Just a voltage dip or spike, or, more often, someone unfamiliar with the seat belts jammed the tab into the buckle at a odd angle. That triggers a "seat belt buckle failure" code. Has there been a new passenger in your car lately? Last time one if mine set, it was the flunky at the dealer who washes cars after service.

No way to check it manually that I know of. You need a tool like a Peake SRS tool to check and clear the code.

Jeron · Jeron's Garage

Use the Peake tool to check the code. It is usually the passenger sensor mat in the pass seat or a seatbelt tensioner.

Basically what Manolito said.

abcxyz · 07-15-2008, 08:04 PM

Thanks for the replies. I have no idea what a Peake tool is. I guess the next time I take my car for an oil change, they can check it right? Does it take long to check? Wonder if they'll charge me to check it.

Not sure what triggered it to come on. It just came on after the weekend. I dind't drive Saturday or Sunday and then Monday it was lit. Weird. I just don't want it to unexpectedly blow up or something.

Jeron · Jeron's Garage

Search for Peake tool, Pelican sells them. Dealer will probably charege you to cheak/reset the light.

The bag will not deploy unexpectedly.

carguyca · 08-01-2008, 06:57 PM

i have a 1997 328i 4 door, and my airbag light came on, and it was the driver side seatbelt pre-tentioner, im pretty sure that might be your problem, its a common problem, im guessing its caz it gets used so often, it will run u maybe like $250-300 from dealer

Wayne 962 · Wayne 962's Garage

The scanner tool is the only definitive way to figure out what is wrong. Most shops will charge you a $30 diagnostic fee, or we sell the tool as well. The most common failure components are the seat belt sensor, and the actual seat occupancy sensor - the main parts that receive the most wear. It's possible that the airbag won't come on in an accident, although I do know of one documented case where there was an error on the dash, and the airbag still worked properly. If it's related to the occupancy sensors (either the seat belt switches or the occupancy sensor), then I would guess it would fail to "activate" in a crash. You can also test the sensors yourself to see if they are working...

-Wayne

///MX · 08-22-2009, 02:14 PM

Hello, I have a '98 M3. I am getting the airbag code for the passenger sensor. Is there a DIY for replacement and what parts do I need to order? Can I replace it with the seat in the car or do I need to remove it? Thanks.

Manolito · 08-22-2009, 02:44 PM

First, remember that on an e36, 9 times out of 10 when the SRS sets a code, nothing is really wrong. Just a wierd combination of events like a voltage spike, or someone tossed something on the seat sensor, or someone unused to the seat belt buckles jambed the buckle together at an odd angle. In those instances, you reset the SRS light and forget about it.

On my two '97 328s, I have had a dozen different codes through the years and I have not replaced anything since the second seat belt buckle was replaced under warranty, and I figured out that there was really nothing wrong with those seat belt buckles.

If the light returns with the same code, then you may actually have a problem.

Pulling the seat is not difficult, and I expect that you will need to pull it. The only thing to watch is the tips of the seat rails. They are razor sharp and will do great damage to your car's interior and exterior as you wrestle with that seat (Sob!) . Put a pair of old socks over them.

Also be careful with the seat belt tensioner. Most have safety locks. One of mine does and the other doesn't. If it has a lock on it, turn the slot head screw to lock it so it cannot activate while you work on the seat. The color will change in the sight hole to tell you when it locks.

///MX · 08-22-2009, 06:44 PM

Thanks for the tips. I've reset it twice and it came back. Even though the code was for the sensor, I might try buckling/unbuckling the seatbelt before I reset it again. I found the DIY in the project book. Follow on question, do I need to replace the sensor mat and the control unit (the black box), or just the sensor mat?

Manolito · 08-23-2009, 05:30 AM

We are out of my realm of experience here, but I would first examine the wiring to the sensor for any sign of physical damage or corrosion in the plug. If someone has worked under the seat before, they may have left the wire where it could get pinched by seat adjustment.

Then I would replace the sensor. If the control unit is reporting a valid code and resetting properly, it appears to be in good shape. When I had an SRS control unit fail on a '90 Volvo, it reported codes that were not in the book, and refused to clear.