W211 Airbags & Pre tensioners

Page may contain affiliate links. Please see terms for details.

phill993

New Member
Joined
Jan 17, 2010
Messages
26
Location
Cambs
Car
E320CDi Estate/BMW 525i Touring/Porsche 993
Hi, new here so hope I am posting in the correct area.

My 2007 w211 E320Cdi Estate has been involved in a head on collision. The drivers airbag and seatbelt pre-tensioner were discharged as expected, but I am bemused by some other occurences - namely, the drivers seat squab seems to have moved forwards and some webbing is visible where the seat squab meets the seat back, also both the rear seatbelts (though not occupied or in use at the time of the crash) are pulled tight as if they too have some kind of tensioner applied to them.

My question is does anyone have knowledge of the W211 airbag/seatbelt set up and could tell me what will need replacing to make this system safe for the future after the front of the car is repaired.

Clearly, the drivers airbag and seat belt pre-tensioner will have to be replaced, but will the drivers seat squab return to it's normal position when the tensioner is replaced or are other parts required?
What about the airbag control unit, does that need replacing or can it be reset? (where is it located)
Is there a separate crash sensor that will need to be replaced or reset? (if so, where is that located)
What about those rear seatbelts, can they be reset or do they also need to be replaced?

Would be grateful for an advice/hints on these issues

Phill
 
Last edited:
The rear seat belts have blown and need to be replaced , as will both front seat pre tensioners , the drivers seat squab this could be the side impact air bag . The air bag control unit may not need to be replaced , if it needs to be it is located under the ash tray .
The pre safe systems will reset , the head rests can be pushed bact and locked with the special tool in the owners hand book .
 
The rear seat belts have blown and need to be replaced , as will both front seat pre tensioners , the drivers seat squab this could be the side impact air bag . The air bag control unit may not need to be replaced , if it needs to be it is located under the ash tray .
The pre safe systems will reset , the head rests can be pushed bact and locked with the special tool in the owners hand book .

Thanks for the info, The tensioner on the front passenger side doesnt seem to have blown and getting 6 codes on OBDII reader, 2 for the rear ETR's, 2 for the drivers airbag (squib1 & 2), 1 Drivers ETR, 1 low voltage warning. How will I know if the control unit does need replacing? Headrests, spotted in the manual how to reset these but cant find the special tool - will have to get one from dealer as I can't make a screwdriver do it!

Thanks again, Phill
 
I fixes an E280 a while back , it had blown the 2 front tensioners , the 2 rear and both roof bags , the control unit did not need replacing , i just replaced the parts and cleared the codes . Id try doing the same , when all the blown parts are replaced the fault codes should all read STORED , not CURRENT AND STORED .
 
9/10 the control unit will need replacing
 
Thanks guys, have the tensioner and seatbelts and airbag on order from MB dealer (after taking out a new mortgage!) am also changing the front crash sensors just to be sure. Will connect up and give them a try before changing the controller.

Shorty, when you say the codes are stored, does that have any effect on the performance of the car? Can these codes be cleared completely?
 
If the codes are stored then they are not effecting the car , and have been fixed or where caused by low voltage . If the codes are reading current and stored then there is a problem
 
W211 seat belt pre-tensioners

Hi Guys, im in need of a bit of advice if you will,
i have recently bought a W211 sport with 38000 miles and its mint with no accident damage at all, now with the seatbelt pre tensioners do they tension into you when you buckle up or not?? its just i have driven this model a few years ago and cant remember if they do or not.
im lucky enough to have parents that usually buy a new ML's every few years and get to drive them and they all do and i wasnt sure if i am getting confused with them both? could you help
thanks Palmersol
 
Hi Guys, im in need of a bit of advice if you will,
i have recently bought a W211 sport with 38000 miles and its mint with no accident damage at all, now with the seatbelt pre tensioners do they tension into you when you buckle up or not??

They don't. The pre-tensioners are one-off pyrotechnic devices that operate only in crash situations.
 
Thanks Troon, now i can finally put that one to bed thanks for you knowledge
 
Hi I know this is a old thread but how did you get on I'm currently doing the same on a ml280 but been told a clock spring on the steering wheel is also needed? Also are new crash sensors really needed
Thanks

Sent from my SM-G920F using Tapatalk
 

Users who are viewing this thread

Back
Top Bottom