SRS light staying on ... then off

[aliquis]

Just last week I bought a 1995 S320. I love it! One of the "little" things that needed done on this beauty was front seat upholstery and interior trim. So I took it to a local trim shop, where they replaced a couple panels on both front seat bottoms, and also replaced the vinyl cover on the seat posts (I think that's what they are called ... the uprights between front and rear doors on both sides). They also tightened and added some foam to the front seats to remedy 14 years of sagging and wear and tear.

So ... here's the problem. After I picked the car up today, the SRS warning light is staying on longer than it should be. After starting up, the light stays on for about 3-4 seconds (normal), and then goes off (normal). Then, about a second later, it comes back on. It then stays on for about 2-3 minutes (not normal), then it goes off again and stays off.

My questions:

1) I'm assuming that when the trim shop took out the seat cushions and/or the seat posts they somehow disconnected a sensor ... I don't know ... but what could be causing this the SRS light to stay on, and then turn off? I know the SRS sensor monitors not only the airbags but also the ETS and the seatbelts ... so one of those systems must have been effected by my trim work.

2) Is the airbag system working, even tho I get this warning light (which then goes out)? Obviously, I need to fix this situation, but how unsafe am I as I figure it all out?

Thanks to all for any help!!

Tom

[carnut]

This is usually a failed or dirty clock spring under the steering wheel. The clock spring must be able to rotate with the steering wheel and still maintain an electrical connection to activate the air bag. If dirty or worn, the SRS light will intermittantly come on. The air bag will not deploy while the light is on. The dealer can confirm the cause by retreiving the code from the body computer. The only possible connection to the seat repair would be a code related to the seat sensor. Do the diagnostic and if a seat sensor code, present the diagnosis to the trim shop and ask for help on the repair.

[tecqboy]

Use the forum search tool and do a search on "SRS" light and "seatbelts". I believe that there is some correlation which should help you resove the issue. Welcome to the forum.

[aliquis]

So, first off, thanks to those who replied. It's always hard to find your way around a new car, and your advice was helpful.

I have now solved my problem, and I thought I would share the outcome so that people who encounter this in the future might get some help.

Again, mine is a 1995 S320 ... after having the upholstery replaced on the seats, I had a SRS light that came on and stayed on for about 2-3 minutes, then went out.

I pulled the seats out this weekend so see if there was any clearly unplugged sensors, etc. that the body shop might have missed. Hoping that I might be able to clear the code out of the computer, I disconnected both sides of the battery while I worked (a couple hours).

I didn't find any unplugged sensors, but I discovered that the trim shop had made a royal mess under the seats: broke all four pieces of trim on the seat rails, broke the automatic seatbelt tensioner by hooking it up incorrectly (I think that's what it's called ... it's the cable that runs from under the seat to the upright between the doors to raise and lower the height of the seat belt as you move the seat back/forward), and broke the passenger side lumbar support valve. What a mess. But I was able to figure it all out and get it hooked up correctly and fixed. Then I fired it up ... seat belts and everything else worked fine, but SRS code was still there.

Went to AutoZone and borrowed a OBDII scanner (yes, the 1995 S320 is OBDII). Plugged it in, and got no codes. Huh. That's when I learned: 1) AutoZone loans out OBDII scanners for free (take note DYIers), and 2) the OBDII scanner will only read check engine light codes. OK. So I was advised to go over to the local independent MB garage (conveniently, across the street).

At that garage I learned that when the computer picks up an SRS code, it is a permanent code that can ONLY be cleared with a "dedicated laptop and vehicle specific software" (that's what I was told, but can't verify that). I was also told that the code occurs when you have the seat belt disconnected, and turn the key in the ignition. Pull the seats, and leave the key out, no code (again, take note DYIers). Cost to clear the code: $80 (I swallowed hard, and was told, "it's a $20K computer system" ... again, I can't confirm that).

Everything now is fine. So what was learned?

1) If you take your car to a body/trim shop for upholstery, be SURE they know how to pull the seats out of YOUR car ... or better yet ... pull the seats yourself and bring them in. This way, you'll know the person pulling the seats actually gives a d*%m about your car.

2) AutoZone loans OBDII scanners for free.

3) DON'T turn the key in the ignition if you've got the seats out.

4) SRS codes can ONLY be cleared (I'm told) by a fancy laptop/software that you can't afford (but the dealer/garage can, and you have to pay up if you want to get rid of the code).

How much did these lessons cost me? $80 to clear the code, $85 to replace parts and trim pieces the body shop broke, and a full day of my time. Hope someone can learn from my experience and save both time and money.

[Pete Geither]

Had the same problem with my 95,,,, it was the drivers seatbelt buckle.