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Discussion Starter #1
Do we have an Experienced Expert on the SRS system.

This light had been doing some strange things, now it stays on.

I have several questions.
- Is this a safety issue, the car still runs and a friend of mine who has a 2000 210 has a piece of electrical tape over the light and just drives it. Do the air bags still work?

- How many Sensors are there and where are they? Drivers side seat or seat belt, passanger seat/ seat belt?

Before I tear my car apart I would like to know as much as I can, the module looks like the easy part, I need to know functionality and design information.

I will build a diy on this one but where do I start?

So if you have first hand knowlage please let me know.

THX
B
 

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if theres a single problem with the SRS system, all teh airbags become inactive. I know that on my car, a 97 e420, my father was in an accident with it and afterwards he replaced all the airbags and computers, but the light was still on. It turns out that the driver side seatbelt had to be replaced as well because apparently they are made to go through only one airbag deploying. so if your light is on, your airbags are most likely not working. It is possible to see what code its bringing up and see what the exact problem, but it requires diagnostic from teh test port thats underneath the hood, not the typical OBD II port
 

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Check

all wires to the passenger seat occupancy switch.If everything is hooked up the switch itself may be bad.Starteck has the r/r.Other members have had the same problem.Not I fortunately, so you need to search for someone who has suffered the replacement.
91 Seats/SRS
lists the part and the location someone with the wis might give you the diy
ohlord:bowdown:
srs is not functional till you get it done.So on safety side a trip to the star machine at a good indie might be prudent and then when located you do the diy.:thumbsup:
 

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you need check the second row seats, the all the wire connector and some in the cd changer. try to find out the loose conection. I had my fixed ML 320 year 2000.
 

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Discussion Starter #5
Great Help but where is the driver ass mass?

Thanks form, the diagrams are great, and experience a great help, but.

I don't see a connection, or picture of a 'ass mass' drivers seat sensor. Right before this failure the srs light would come on and I would change position in the seat, or change the seat adjustment and the lifght would go off.

I am ASSUMING that there is a sensor of some kind in the drivers seat, am I wrong? Has anyone taken the drivers seat pad apart for this fix??
All i see is the seat belt switch, and seat belt tensoner connection.?

I also ASSUME that the passanger side seat ass mass is bad and causing an error, I won't know for sure until latter this week when I get a star system diagnostic.

Again, ANY experience/knowlage will help.

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I bought my car E320 4 Matic at the end of November and this light was on. They had to replace a sensor that was in the front passenger seat (550.00$).Still on warranty I had just bought the car.Hasn't lit since. I saw the part it was about the dimension of the seat about 1/16'' inch thick.Hope this helps.
 

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Discussion Starter #7
And away we go....

I checked with the local glitz and glam dealer and can get the occupancy sensor pad for 179US$ ans seperate foam seat pad for 140US$ if that is the problem.

I will take both seats out and check all this weekend.

Thanks for all the input.

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Discussion Starter #8
SRS Light - Occupance Sensor

A vist to my Indie revealed several codes on the SRS. The constant was caused by a bad Occupancy SSensor in the passanger seat.
So here are pictures of this parts swap.
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Discussion Starter #9
SRS Light - Occupancy Sensor 2

The next 10 pictures.
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That

was easy:thumbsup:
I made the call,you did the great diy:D
you will be stickyfied for sure:thumbsup:
ohlord:bowdown:
 

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Discussion Starter #12
It's fixed

And it really was an easy fix with the seat out of the car.
I went back to my Inde and he pluged in his star and reset the light and all is well, sort of.
The star said that the drivers side seat belt switch was going bad so that will be next week. The indie suggested just cleaning some of the chips and milk duds out of the switch in the belt latch, but the light is out and all is working.

OBTW, MB required the vin number even though I had the part number for the sensor, any ideas why?
The indie didn't charge for the diagnosis so the whole deal was 179$US. I took 3 hours with trying to figure it out then taking pictures, maybe half that with pic's.

Occupancy sensor is EASY, diy!

gotta love MB.
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Dealers

always ask for the vin,sometimes it is needed if they had a mid production part change.Good idea even when you order from autohausaz.com,and an even better idea when getting dealer parts.They usually screw up the order anyway so at least the vin gives you a fair chance
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FYI: My experiences with dealer parts departments are they are either stupid/lazy, or their systems do not allow them to search for a part by description. There have been a few things they could not find until I gave them the actual MB part number, most of which I got right here on Benzworld.org! ;)
 

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SRS light - still unclear?

Great series of photos MrBSMITH. They have convinced me not to try it myself

Can I confirm one thing, my indie car mechanic called a MB main dealer mechanic and he said that the sensor in the passenger seat weighs the occupant and then will deploy the air bag and seat belt pre-tensioners slightly differently to suit a child or small adult, BUT THAT THEY WILL STILL DEPLOY THE AIR BAG AND PRE-TENSIONERS EVEN IF THE SENSOR IS BROKEN. Can anyone confirm that?

I would never have a child in the front seat and plan on selling this car in a year, The part and installing is working out at €300 ($450)
 

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My

understanding is that if the srs light is on the system is deactivated and the air bags will not deploy.It is unsafe to drive in that condition should there be a mishap.It states that in the manual also.
:bowdown:
 

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Discussion Starter #17
Ditto

It is my understanding, from conversations with MB service personel and research that an srs light indicates a fault or failure in the Bag/Belt system, and that any part of same will not function in the event of an accident.

This is not good 2 me.

The diy is very easy, and the dealer will try to include a new seat pad with the sensor. the Pad cost an additional 125-175US$. I chose to re-use the old pad.

I never let a child in the front seat as my car is sensative to Juice Boxes and spounge bob music.

Hope this helps.


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Discussion Starter #18
From MB,

Supplemental restraint system (SRS) indicator lamp

SRS The operational readiness of the airbag system is verified by the indicator lamp “SRS” in the instrument cluster when turning the electronic key in the steering lock to position 1 or 2. If no malfunction is detected, the lamp goes out after approximately 4 seconds; after the lamp goes out, the system continues to monitor the components and circuitry of the airbag system and will indicate a malfunction by coming on again.

Warning!
In the event a malfunction of the “SRS” is indicated as outlined above, the “SRS” may not be operational. For your safety, we strongly recommend that you visit an authorized Mercedes-Benz Center immediately to have the system checked; otherwise the “SRS” may not be activated when needed in an accident, which could result in serious or fatal injury, or it might deploy unexpectedly and unnecessarily which coild also result in injury.

Also; The seat belts for the front and other rear seats are equipped with emergency tensioning retractors. These tensioning retractors are located in each belt’s inertia reel and become operationally ready with the electronic key in steering lock position 1 or 2. The emergency tensioning retractors are designed to activate only when the seat belts are fastened during frontal impacts exceeding the first threshold of the “SRS” and rear impacts exceeding a preset severity level. They remove slack from the belts an such a way that the seat belts fit more snugly against the body restricting its forward movement as much as possible.

Finally;
Accident research shows that the safest place for children in an automobile is in the rear seat.

Please see your MB owners manual p 77, p236.

ALSO Look in Pietryk for the sequences and thresholds, they are to big to attach.

Hope this helps

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SRS Light and Airbag light...

I had the same symtoms... SRS light on and airbag light on. I bought a new seat sensor and put it in within an hours work. Didn't need to take backrest off, I just peeled back the leather 3/4 off and slid the old sensor out. Check the old sensor but didn't see anything broken. Slid the new one in (with some effort). Plugged it all in, tightended everything up and after a couple of restarts, the lights all went out!! Yeah... 4.5 hours for dealer??? Anyway, during clean up I was looking at the old sensor and noticed that the plastic cover of the wire leads were worn down to the wires and the wire was broken... realized this was my reason for the light. I spliced the wires, unplugged the new sensor (still in seat), plugged the old one in and layed it on seat. SRS and airbag light went out... ARRRRRRGGG. Could have saved $170. If any one is interested in the old (and now working) seat sensor, I'll sell it for $50. If yours is not working, check the wire that comes through the hole in the bottom of the seat at the hole. This is where mine was wearing and cut the wire.
 

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Discussion Starter #20
Thanks Kev

I have a friend that I meet at the OC MB rally bringing his car over in two weeks for a sensor.
I think I will try it with the seat in the car and just pulling the cover off. That would make it a real easy diy!

Thanks for the tip!

B
 
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