Resistor value for seat air bag??

Discussion in 'Gen 2 Prius Technical Discussion' started by northwichita, Apr 6, 2008.

  1. northwichita

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    Hi , I post this question at the end of a long forum and didn't receive a response. What is the resistor value for the seat air bag? (I'm putting in different seats, and accept full responsibility). I've looked a while, both here and 'abroad', and can't find the value. Thanks in advance, Northwichita
     
  2. hobbit

    hobbit Senior Member

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    Since it's probably a nichrome-wire igniter for the squib,
    probably fairly low -- but like the manuals say, you should
    probably NOT go testing it with an ohmmeter since that's got
    some possibility of making it go off. What you might do instead
    is when you got to change out your seats, or even beforehand
    just to debug it in advance, is tap the squib wires at one of the
    connectors [on the ECU side, not the airbag side], disconnect
    from the airbag itself, and play with resistances between, at a
    total guess, 1 and 10 ohms and see when the airbag controller
    stops complaining about a bad squib.
    .
    In googling around I found this excerpt from US patent 6597181:
    .
    _ ... A normal resistance for a squib
    _ element is typically about 2 ohms. A resistance measurement greater
    _ than about 4 ohms or less than about 1 ohm usually indicates a fault
    _ in the squib element. Ignition of a typical squib element requires
    _ about 1 amp of current in an ignition pulse. Resistance testing is
    _ typically performed using about 50 milliamps passing through the
    _ squib element.
    .
    It may be different for the Prius. Try to find the middle value in
    between the endpoints of when the car issues the warning. Remember
    that it takes up to four reboots to clear errors in the car, so you
    should start each test from an errors-cleared state. Be careful,
    don't blow your face off, or if you do then make sure someone
    captures a high-quality mpeg of the event, etc etc.
    .
    Then report back here, so it goes into the general pool of
    knowledge!
    .
    _H*
     
  3. northwichita

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    This article, which is a well written article for switching off the air bag,
    link failed so to a search ---- autospeed.com and Switching Off an Airbag ------

    ....... also quotes 2 ohms for Honda, so will try that this week. Thanks.
     
  4. dogfriend

    dogfriend Human - Animal Hybrid

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    Yes. This would be guaranteed to be most popular on YouTube. :evil:
     
  5. racerbob

    racerbob Member

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    2.2 ohm works for everything I've tried.
     
  6. northwichita

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    Tried a resistor,1/4 watt 2 ohm, works on my brief trial startup. No air bag warning!! Thanks
     
  7. dogfriend

    dogfriend Human - Animal Hybrid

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    What kind of seats are you installing? Pics?
     
  8. Jasper2k

    Jasper2k From HEMI to Prius

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    Excellent! I need to do the same thing to install my Recaro (full responsibility my own).

    The seat airbag connector is the simple yellow two-wire type, it seems? Resistor across the two wires, subbing for the squib?

    Thanks :)
     
  9. northwichita

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    [quote=dogfriend;595333]What kind of seats are you installing? Pics?[/quote]

    I'm installing a bench seat for my rural mail carrier job, yes different I know. Sorta of 50's look to the cabin . I just feel safest driving from the 'middle' vs the right seat which many carriers do. I haven't driven the car on the job yet, soon.

    Jasper2k Excellent! I need to do the same thing to install my Recaro (full responsibility my own).
    The seat airbag connector is the simple yellow two-wire type, it seems? Resistor across the two wires, subbing for the squib?

    Right. My understanding is it's just important to avoid applying any power which includes voltage testing , static shocks..etc.,when dealing with the airbag system. If the SRS senses wrong resistance on startup, too high or too low, it sets a code.
     
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