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Thread: Throttle position sensor training?

  1. #1
    Ricoshay
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    Throttle position sensor training?

    I recently replaced the battery in my 05-R12RT. In accordance with the instructions in my Service Manual, I did the following:

    1. Switch on the ignition.

    2. Without starting the engine, fully open the throttle once or twice so that the control unit of the BMW engine management system can register the throttle-valve positions.

    3. Switch off the ignition.

    That was 300 miles ago and my Engine Management Computer is still chasing its tail as evidenced by the mpg display which now varies between 37 and 47 mpg. Normally the mpg display is quite stable and accurate within +/- 2mpg.

    Is there a secret incantation required to retrain the the EMC?

    John

  2. #2
    Getting lost...
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    I don't believe the MPG calculation is related to the TPS. The proceedure is done to quickly retrain the ECM for the full range of the throttle.

    Have you reset the MPG display recently?

    The TPS proceedure can always be done again at any time without harm.

  3. #3
    Ricoshay
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    Quote Originally Posted by Motorwerk View Post
    I don't believe the MPG calculation is related to the TPS. The proceedure is done to quickly retrain the ECM for the full range of the throttle.

    Have you reset the MPG display recently?

    The TPS proceedure can always be done again at any time without harm.
    You may be right, but I think the wandering mpg calculation indicates the ECM is still trying to find a correct setting for some control variable. Are there other control settings that must be learned?

    Upon first starting the bike I noticed that the mpg display had been reset by the power interruption that resulted from the battery installation. I reset it again after a few miles in hopes of stabilizing the reading. No significant change. It's still searching.

    I did the TPS procedure after the ECM had gone through its normal start-up procedure, next time I'll try doing it during the initialization period. The Manual doesn't say whether to wait or not. Does anyone know if it makes any difference?

    I had this same problem last Fall when I installed an auxiliary power source direct to the battery. I didn't know about the TPS procedure at that time and it took several thousand miles for the mpg display and the actual bike mileage to stabilize. I had hoped the TPS procedure would reduce the learning curve this time.

    Thanks

  4. #4
    Getting lost...
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    I'm not aware of anything else that needs to be retrained.

    If it were me I would wait for the start-up check procedure to complete before moving the throttle. It may not matter but this way it ensures that everything is working correctly prior to making the adjustment.

    How often do you reset the MPG display? At every fill-up would be the suggested minimum. I have reset it several times while riding and it does take some time to settle down depending on what kind riding you're doing at the time.

    It will vary considerably right after being reset since all the comparative data has been removed. Mine takes about 5-10 miles before it settles down and then of can change depending on how I'm riding.

  5. #5
    Ricoshay
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    My mpg display acts the same way as yours Motorwerk, normally. I seldom reset the display unless I'm doing something dramatically different and want to know the impact on mileage. Like pounding the Interstate on a trip.

    However this relearning cycle after a total power interruption is a whole different case. As I said before, normally the mpg display doesn't vary very much. But in this relearning phase my actual bike mileage for a whole tank of gas has gone as low as 33 mpg. This happened last Fall and at the time I was on I-70 and using the cruise control in 6th gear. As I said, it took several thousand miles for the bike to stabilize at its now normal 42 to 44 mpg. Now it appears I'm starting that cycle all over again.

    I'll certainly try the TPS procedure again when the rains subside.

    Thanks

  6. #6
    Getting lost...
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    My only other guess as to the cause would be the difference in software versions.

    I'd be willing to bet there was an update that may have addressed this issue.

    Perhaps if you're still within warranty a trip to the dealer may be worthwhile.

  7. #7
    Ricoshay
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    Quote Originally Posted by Motorwerk View Post
    My only other guess as to the cause would be the difference in software versions.

    I'd be willing to bet there was an update that may have addressed this issue.

    Perhaps if you're still within warranty a trip to the dealer may be worthwhile.
    BTDT

    Thanks

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