Yet another MFSW Question.

Discussion in 'B6 platform' started by Roch_Ultrasport, Mar 19, 2014.

  1. Hello All;

    I've been searching this board as well as others and can't seem to find a definitive answer to a question.
    I drive a MY 2005 A4 1.8T 6MT Ultrasport.

    Related to the Steering wheel according the ETKA and confirmed by the parts department at the dealership (using a VIN lookup) I have the following installed.

    4E0 953 541 B --> Cancelling Ring with Slip Ring and Steering Sensor.
    8E0 953 549 R --> Electronic Module for Steering Column Combination Switch (VCDS has a N suffix)

    These are the part number everyone lists needed for the B7 MFSW retrofit into a B6. But if I already have them is there a need to order? Is there any difference in the parts between the B7 and B6 if the part numbers are the same. Which they are when I look under B7 in ETKA.

    I was looking to get a B7 S4 MFSW 8EO-419-091-DN-TNA with associated air bag.

    Thank for Reading.
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    PetrolDave Super Moderator

    You really should think VERY carefully about whether the risk of the airbag not going off is worth the cosmetic difference.

    The B6 has a single stage airbag controller but the B7 wheel has a dual stage airbag - reports on many Audi related websites have shown that there is no definite way of wiring the dual stage airbag into the single stage controller which will GUARANTEE that the airbag will deploy when needed. Wiring both stages in parallel has been shown to produce intermittent error codes, wiring both in series produces a permanent error code and wiring just the second stage has (in the only recorded case for which there's been evidence) failed to deploy.

    Having spent some time developing the airbag system for one of The Big Three my considered professional advice is simple - don't do it. Live with the naff cosmetics of a B6 MFSW rather than the naff cosmetics of a face that has hit the nut on the end of the steering column.
  3. Dave;

    Thank you very much for replying. I've been following this topic for several years now and always see your good advice posted for this type of question. I have also read here, and on other boards, the lively discussion on whether or not the air bag will deploy. While I am not willing to risk my health/life for a cosmetic upgrade, there are some things which I wanted cleared up.

    VCDS shows my Air Bag Controller to be 8E0 959 655 K. When I look up the same part in ETKA under MY 2006 A4Q it has the same controller/part listed (suffix may be different).

    Now I have the following parts installed which are found on the B7 according to ETKA/VCDS and the parts department at the Dealership.

    4E0 953 541 B --> Cancelling Ring with Slip Ring and Steering Sensor. ETKA --> F 8E-5-000-001>>
    8E0 953 549 R --> Electronic Module for Steering Column Combination Switch (VCDS has a N suffix). ETKA--> F 8E-5-000-001>>
    8E0 959 655 K --> Air Bag Controller. ETKA--> F 8E-4-140 000>>


    Comparing the Standard Equipment lists for each model year.

    2005 Audi A4 Standard Equipment List
    http://www.audiworld.com/model/a4/05/05A4Sedan_Equip.pdf

    2006 Audi A4 Standard Equipment List
    http://www.audiworld.com/model/a4/06/A4 sedanav SE.pdf

    Other than the '06 having the "Advanced airbags (FMVSS 208), 2-stage including occupant protection; indicated in cabin by "Pass Airbag off" amber indicator light above radio", both state that the vehicles carry dual stage air bags.

    I am trying very hard to understand where the information regarding all B6's have Dual Stage Air Bags comes from.
  4. I went into Elsawin and looked at the wiring diagrams for the B6

    -Airbag for driver, passenger with seat belt tensioner and side Airbag From 2002 m. y.
    -Airbag for driver, passenger with seat belt tensioner and side Airbag From 2004 m. y.

    # of Wires Between Airbag Spiral Spring/Return Spring With Slip Ring and Airbag Control Module (2)
    # of Driver's Airbag Igniters (1)

    Airbags and Safety Belt Tensioners From November 2004

    # of Wires Between Airbag Spiral Spring/Return Spring With Slip Ring and Airbag Control Module (4)
    # of Driver's Airbag Igniters (2)

    So it would appear only the later models of the B6's 11/2004 were equipped with dual stage air bags. That mystery is solved.

    However my car was made in 07/2004 and has the same parts for the Cancelling Ring and Air Bag Controller as the Dual Air Bags cars.
    That's something I still need to work on.
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    PetrolDave Super Moderator

    I think you've got that very wrong:

    AFAIK ALL B7s have dual stage airbags.

    It's always been said that all B6's have SINGLE stage airbags, but it's entirely possible that Audi introduced dual stage airbags as a rolling change late in the life of the B6.
  5. Never doubted B7's have dual stage airbags and posted the answer to my question in #4 above. I now know that B6's produced in 11/2004 will have been fitted with dual stage air bags and I can work off that.

    As an aside. Doing some research I came a across a document from Audi relating to their Airbags and deployment. I'll post the bit about dual stage airbags as it might be useful to some.


    Adaptive front airbags

    Some of the new Audi vehicles are equipped with driver and passenger airbags which consist of the so-called adaptive airbags. The cushioning effect of these airbag systems can be influenced by the activation of pyrotechnical units to the airbag gas generator or airbag module housing. This enables a different degree of filling for the airbag.


    2.2.2 Dual-stage front airbags

    The ignition of the propellant takes place in one stage with an airbag that has a single-stage gas generator.


    Some of the Audi vehicles are equipped with dual-stage airbags. With this airbags, the gas generators work in two stages in which both propellants are sequentially activated. The control module for safety systems decides what the timing should be between the two ignitions based on severity and type of accident. The timing difference can, depending on the vehicle, be anywhere between 5 and 200 ms.


    The second stage ensures that the airbag is filled with additional gas volume. The timing difference between the ignitions determines the inflation stiffness of the airbag: if the second ignition happens later, then the airbag pressure from the first ignition will have partially gone down, the airbag will be inflated with less pressure. If the ignitions take place right after each other, then the airbag pressure from the first ignition will not yet have gone down and the airbag will become stiffer.


    In principle both stages will always ignite. This will avoid a propelling charge remaining active after the airbag deployment. <<-- Emphasis was in the document.
    • Premium Supporter

    PetrolDave Super Moderator

    The phrase "In principle" is a classic disclaimer that means it should but if it doesn't we didn't tell you it would.

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