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Thread: '03 K12RS TPS reset - again

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    Kein Nasebohrer RBEmerson's Avatar
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    '03 K12RS TPS reset - again

    Sorry - '03 K1200RS
    The key on, twist, twist, twist drill is no longer working for me. I do key on with my left hand and start twisting almost instantly after the idiots light up. I go to WOT (hit the stop) three times, fire up the motor and... just as miserable at the low end as before. Am I missing something on this voodoo or...?
    When it comes to thinking, some people will stop at nothing.

  2. #2
    MOA #24991 Pauls1150's Avatar
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    Not sure about your particular model, but my belief is that you MUST wait for the computer to completely boot up and run its self-check before doing the reset.
    Twist slowly and control the return too.
    Note that this resets the "initial values" of the fueling map; "actual riding condition" values are automatically trimmed in as you ride, and this takes a ride or two. Since we don't spend a lot of time at low rpm, that part of the map may take more time to self-remap. (It sure does when I pull the battery from my car...)
    Or you may actually have a bad TPS? Not common but it happens.
    Does it run well at mid and high rpm?

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    Kein Nasebohrer RBEmerson's Avatar
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    OK, it's possible (likely?) I'm jumping on the reset routine too soon. How much time do I have before it's too late to reset the TPS? The rotation should slow, not fast? If so, that's something else I got wrong.

    Aside from the TPS issue, everything else works as it should. The local Interstate raised the speed limit recently, making runs to 80-90 (by GPS - speedo is slightly fast) reasonably safe from LEO. Everything works fine.

    I'll try the wait and slow drill a few times and see what happens.
    When it comes to thinking, some people will stop at nothing.

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    MOA #24991 Pauls1150's Avatar
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    It's never "too late". Just wait until ALL the lights stop blinking and the ABS has gone thru its routine; this whole thing is maybe 5 seconds or so.

    The rotation doesn't have to "crawl", you just want to be sure the computer has the time to "see" the entire voltage sweep with no "holes" in the data. Older TPSs used a wirewound element (dual potentiometer), and the newer ones are a solid carbon amalgam, but either one could get wear or dirt on where the wiper contacts it; also note that if it has an internal crack, that would certainly screw up the attempt to reset it.

    tps.jpg

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    RB,

    Find a friend with a GS-911 diagnostic tool.

    It will help you set the TPS and/or find out if you have either a bad TPS or a bad throttle actuator.

    The bike is 13 or 14 years old, things wear out.

    I went through several set/resets with a GS-911 on our 2002 K1200RS.

    It's not that difficult...once you get the hang of it.

    RealOEM.com is a good site to help figure out how things go together: www.realoem.com/bmw/select.do?kind=M&arch=0

    Good luck on getting it sorted out.

    Deryle Mehrten
    Sierra Vista, AZ USA

  6. #6
    Kein Nasebohrer RBEmerson's Avatar
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    OK, I have a better sense of timing the routine. I'll report back on how it works out.

    TPS' in general aren't my friend. I spent far too much time sorting out the TPS on our '90 VW camper. I replaced the throttle body (a story in itself - the installation was easy, the reason why... oh nevermind) and the TPS that came with it was supposed to be good to go. Good to go into the trash, perhaps. I wound up buying a $75 TPS that, at least, could be set up without consulting a voodoo priestess. The thing is simply a micro-switch that's twisted to spec and locked down. This TPS looks more like the pot on the air mass sensor's "barn door" flap. Which needed a good cleaning. Sigh...

    If the twist 'em routine doesn't work, I may just invest in a GS-911 rather than take it to the dealer just read "The Codes".
    When it comes to thinking, some people will stop at nothing.

  7. #7
    Kein Nasebohrer RBEmerson's Avatar
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    I'm now advised to wait until the idiot lights stop their start-up light show, and then roll the throttle with ...um... due deliberation, not crank thing like a man obsessed. The result are somewhat better. Only. What I seem to be up against is how long the computer will accept calibration activity.
    When it comes to thinking, some people will stop at nothing.

  8. #8
    MOA #24991 Pauls1150's Avatar
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    The computer is ALWAYS "trimming" the map; the only way to "speed up" the low-rpm trim is to spend more time at the bottom of the rev range, which a K motor does not like anyway.

    The K12 had several recalls, possibly including the airbox which had a direct effect on idle & low rpm running (I may have the year/model confused) ... have you verified that all recalls have been performed? Some years/models have had issues with vacuum lines that need to be R&R'd.

    And there may be a different solution entirely to this problem which has not yet been hit upon...

  9. #9
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    Does any of this map reading apply to the early jetronic computers? Like an '85 K? Or are those control units/computers set, period?

  10. #10
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    Quote Originally Posted by 8ninety8 View Post
    Does any of this map reading apply to the early jetronic computers? Like an '85 K? Or are those control units/computers set, period?
    No, does not apply. These very early FI systems had very few sensors and virtualy no adjustability. But they were light years better than carburetors.


    LONG MAY YOUR BRICK FLY!

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    Lee Fulton Forum Moderator
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  11. #11
    Kein Nasebohrer RBEmerson's Avatar
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    Quote Originally Posted by Pauls1150 View Post
    The computer is ALWAYS "trimming" the map; the only way to "speed up" the low-rpm trim is to spend more time at the bottom of the rev range, which a K motor does not like anyway.

    The K12 had several recalls, possibly including the airbox which had a direct effect on idle & low rpm running (I may have the year/model confused) ... have you verified that all recalls have been performed? Some years/models have had issues with vacuum lines that need to be R&R'd.

    And there may be a different solution entirely to this problem which has not yet been hit upon...
    I still don't understand whether or not there's a "window" for doing the throttle grip routine. I think you're saying I could actually start the motor, stop it with the kill switch, rotate the throttle, re-light the motor without using the key, and still get the TPS recalibration?

    I have nothing from the PO about the bike's service history.
    When it comes to thinking, some people will stop at nothing.

  12. #12
    MOA #24991 Pauls1150's Avatar
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    No window.
    Key on and kill switch in the Run position.
    Don't start it, just let it boot up.
    Twist slowly a few times.
    Key off.
    Done.

    Present your VIN to your local BMW service manager - if recalls or "campaigns" were done, it's recorded in ze master komputer. They will also have history of any other dealer services.

  13. #13
    Kein Nasebohrer RBEmerson's Avatar
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    Quote Originally Posted by Pauls1150 View Post
    No window.
    Key on and kill switch in the Run position.
    Don't start it, just let it boot up.
    Twist slowly a few times.
    Key off.
    Done.
    Key off is required? (Just trying to make sure I get the voodoo right)

    Present your VIN to your local BMW service manager - if recalls or "campaigns" were done, it's recorded in ze master komputer. They will also have history of any other dealer services.
    Hmmmm... good point.
    When it comes to thinking, some people will stop at nothing.

  14. #14
    Curmudgeon At Large Bobmws's Avatar
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    Quote Originally Posted by RBEmerson View Post
    Key off is required? (Just trying to make sure I get the voodoo right)


    Hmmmm... good point.
    Yes,key off. I think I said that in the other thread, but I'm old and may have forgotten....

    Also, have the dealer check service records, there was a cold start update for '03 & early '04. Not sure if that's applicable to your issue, but should be checked.
    Bob Weis
    '04 K12RS - Hannigan Hack

  15. #15
    Kein Nasebohrer RBEmerson's Avatar
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    Y'know, it helps to get magic spells right or Bad Things Happen.

    I don't have starting issues but I'll follow up anyway. I hope all I find is good news.
    When it comes to thinking, some people will stop at nothing.

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