SRS Light on...
Thread Starter
Member
Joined: Jul 2010
Posts: 92
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e320 4matic wagon
SRS Light on...
My 01 e320 4matic wagon has the SRS light on in the dash and the child safety light on in the window/switch console area. I have done a search over here and @ benzworld and it seems it could either be a faulty passenger seat sensor or broken wire. My question is: how can I detect the broken wire? There are 3 wires coming from my sensor but where do they goto? I could bypass the 3-wire harness but I need to know where it goes to. Thanks all!
Thread Starter
Member
Joined: Jul 2010
Posts: 92
Likes: 0
e320 4matic wagon
Go it:
Check the wires first
My SRS and passenger seat airbag lights came on a few days ago so I followed the excellent instructions in this thread to remove the sensor pad. Before assuming the pad was faulty I thought it was worth the time to inspect the wires.
Visually the wires looked fine, no chaffing or cuts in the insulation. I stripped off the outer insulation to reveal the 3 individual wires which also looked fine. As a final check I stripped back the insulation on each wire close the "box" and checked continuity from that point to the yellow plug. Sure enough, one wire was broken inside the insulation even with no sign of damage from the outside.
When my ohm meter showed no resistance on the white wire I lightly pulled on it from each end and it snapped in half. A quick splice and all is fine. The best part is it cost me nothing but a few hours of time.
If I had to do it again I would test the wires before separating the seat pad (white plastic clips) as the hardest part of the job was getting those clips to catch on the wires sewn inside the seat.
I hope this helps someone avoid the expense of replacing a perfectly good sensor.
My SRS and passenger seat airbag lights came on a few days ago so I followed the excellent instructions in this thread to remove the sensor pad. Before assuming the pad was faulty I thought it was worth the time to inspect the wires.
Visually the wires looked fine, no chaffing or cuts in the insulation. I stripped off the outer insulation to reveal the 3 individual wires which also looked fine. As a final check I stripped back the insulation on each wire close the "box" and checked continuity from that point to the yellow plug. Sure enough, one wire was broken inside the insulation even with no sign of damage from the outside.
When my ohm meter showed no resistance on the white wire I lightly pulled on it from each end and it snapped in half. A quick splice and all is fine. The best part is it cost me nothing but a few hours of time.
If I had to do it again I would test the wires before separating the seat pad (white plastic clips) as the hardest part of the job was getting those clips to catch on the wires sewn inside the seat.
I hope this helps someone avoid the expense of replacing a perfectly good sensor.
Senior Member
Joined: Apr 2006
Posts: 463
Likes: 8
From: Long Island, NY
01 E320
The wires come from the sensor pad in the seat and are tied with a plastic wire tie to a hole in the bottom lf the seat and then plugs into a harness under the seat towards the front. Airbag wires are typically yellow. You can see this if you put the seat back and up and shine a flashlight underneath. In most cases the problem is that plastic wire tied is tight to a sharp edge on the seat bottom. This was a design error. The movement and pressure each time someone sits in the passenger side eventually damages or severs the wires. Result is SRS light and/or the light on the central console
I bought a new sensor and had a friend of mine that does auto uphulstery install it for me since I couldn't get the seat bolts off. It seemed difficult to me but it only took him 20 minutes for the entire job so it couldnt be that hard. If you can get the seat out, it probably would be pretty easy to repair the wire and avoid buying the sensor pad.
By the way, there is no way to bypass this sensor if that's what you're thinking. I tried that.
The irony here is that all this system does is support the installation of a Mercedes baby seat in the front passenger seat. Americans never install baby seats in the front and this system is never used here. It serves no other purpose. It does not disable the passenger airbags when the seat is empty, like american cars do. In other words the only thing this sensor does for 99.9 percent of W210 owners is give us aggrevation.
I bought a new sensor and had a friend of mine that does auto uphulstery install it for me since I couldn't get the seat bolts off. It seemed difficult to me but it only took him 20 minutes for the entire job so it couldnt be that hard. If you can get the seat out, it probably would be pretty easy to repair the wire and avoid buying the sensor pad.
By the way, there is no way to bypass this sensor if that's what you're thinking. I tried that.
The irony here is that all this system does is support the installation of a Mercedes baby seat in the front passenger seat. Americans never install baby seats in the front and this system is never used here. It serves no other purpose. It does not disable the passenger airbags when the seat is empty, like american cars do. In other words the only thing this sensor does for 99.9 percent of W210 owners is give us aggrevation.
