Mercedes SRS WSS bypass

E39MSport

FYI

The passenger seat occupancy sensors on a lot of Mercs can and do fail over time. Throws a fault code on the dash. NCT Fail.

Mr. Merc wants 650 plus vat to fit a new sensor mat into the seat.

Theres a crowd selling bypass kit on ebay that I couldn't see much feedback about on relevant forums. So, I took a gamble and spent the 70 or so sheets.

Got it done today despite the rubbish installation instructions.

It sends a signal to the ECU that the seat is occupied and so the airbags are armed and the fault code diappears.
It works fine which is a relief. Total focker to install. Lots of fiddly messing about under the seat.

Only drawback (and I should have anticipated this) is that it triggers the seatbelt warning light. Need to have the seatbelt plugged in at all times.
Should be okay for the NCT however.

Big Nasty

Good tip - happens a lot on the drivers seat on BMW's too!

So when you turn on the ignition the airbag light comes on as normal and goes off once the car is running like it should, yeah?

cadaliac

Good stuff.

DublinDilbert

I believe you can get the seat mat coded out of the system, with a star tester...

E39MSport

MCMLXXV wrote: »

Good tip - happens a lot on the drivers seat on BMW's too!

So when you turn on the ignition the airbag light comes on as normal and goes off once the car is running like it should, yeah?

Yup, light goes out and normailty returns (apart from the seatbelt beeper)

E39MSport

DublinDilbert wrote: »

I believe you can get the seat mat coded out of the system, with a star tester...

Indeed but I couldn't get my hans on the star kit and Merc won't bypass it for obvious reasons.

pajo1981

MCMLXXV wrote: »

Good tip - happens a lot on the drivers seat on BMW's too!

So when you turn on the ignition the airbag light comes on as normal and goes off once the car is running like it should, yeah?

WTF?

Why would a drivers seat need an occupancy sensor, man?

DublinDilbert

pajo1981 wrote: »

WTF?

Why would a drivers seat need an occupancy sensor, man?

Would explain quite a bit!!!

E39MSport

Update: The male seatbelt clip from a scrapper Passat fits perfectly and stops the setabelt warning light/buzzer on a W211. Job done.

mullingar

Job would be better done if the wire going to the buckle receiver was just grounded;).

No need to remove the passat buckle to belt up your passenger

nialler

The seat sensors on these mercs weigh the person in the seat and will automatically disable the airbag if the person is under 30kg or so I was led to believe, I had two of them fail on a W220 S Class, bugger to get replaced but did it twice for €350 a time with Seamus Mulligan up in Synge Lane.

E39MSport

mullingar wrote: »

Job would be better done if the wire going to the buckle receiver was just grounded;).

No need to remove the passat buckle to belt up your passenger

That would be the better option for me but its the bro's car and all I could see in my mind was the airbag going off as soon as I touch the receiver.

I'll give it some research though - you're right - ta.

JIM POL

i have emulator for most mercedes bmw mazda fiat if eny one need one send pm

-Chris-

Hi Jim Pol,

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