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Thread: 3 gear not accepted

  1. #1
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    3 gear not accepted

    Can anyone help me understand why the third gear only enters after 4800 rpm 130 km / h in manual shift?

    S10_2.5_TCM_T43.hpt

  2. #2
    Advanced Tuner ZeroBoostBuick's Avatar
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    There is no way you can get up to 130 kph in second gear. The gear ratios dictate 130 kph in 2nd gear would be around 10,000 prm

    I know for sure you're talking about 4th gear because at throttle positions above 62 % it's set to automatically shift to 4th at 82 mph (131 kph).

    But I understand what you're saying... there is no reason why you shouldn't be allowed to manually shift to the next gear at any rpm you desire as long as it's above a certain speed so the car doesn't bog from too low rpm after shifting.

    Only thing I see right off the bad is the 4th, 5th and 6th tcc apply/release. the TCC Apply and Release in 4th 5th & 6th gear is set before the trans is even in those gears. This is probably not related to your problem, but could be beneficial to change. You'd get better fuel economy if it works as it should.

    The tcc apply/release is actually what we used to call "Overdrive"

    You want the tcc apply a couple mph higher than the shift for that gear in the corresponding throttle position and the higher the throttle position the higher the tcc apply value should be than the corresponding gear shift. And release should be a couple mph below the apply in that gear/throttle position and have to make sure the release is above the corresponding upshift and downshift...

    I can correct those table for you and post the tune back up on this thread when I'm done with it. I've seen TCC apply/release butchered in plenty factory GM oem tunes.

    It's up to you... You will always have the original tune and can compare the two with the compare feature to see exactly what I did.

    I will also try to correct anything else that doesn't look good.
    Last edited by ZeroBoostBuick; 06-09-2020 at 09:16 AM.

  3. #3
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    Quote Originally Posted by ZeroBoostBuick View Post
    There is no way you can get up to 130 kph in second gear. The gear ratios dictate 130 kph in 2nd gear would be around 10,000 prm

    I know for sure you're talking about 4th gear because at throttle positions above 62 % it's set to automatically shift to 4th at 82 mph (131 kph).

    But I understand what you're saying... there is no reason why you shouldn't be allowed to manually shift to the next gear at any rpm you desire as long as it's above a certain speed so the car doesn't bog from too low rpm after shifting.

    Only thing I see right off the bad is the 4th, 5th and 6th tcc apply/release. the TCC Apply and Release in 4th 5th & 6th gear is set before the trans is even in those gears. This is probably not related to your problem, but could be beneficial to change. You'd get better fuel economy if it works as it should.

    The tcc apply/release is actually what we used to call "Overdrive"

    You want the tcc apply a couple mph higher than the shift for that gear in the corresponding throttle position and the higher the throttle position the higher the tcc apply value should be than the corresponding gear shift. And release should be a couple mph below the apply in that gear/throttle position and have to make sure the release is above the corresponding upshift and downshift...

    I can correct those table for you and post the tune back up on this thread when I'm done with it. I've seen TCC apply/release butchered in plenty factory GM oem tunes.

    It's up to you... You will always have the original tune and can compare the two with the compare feature to see exactly what I did.

    I will also try to correct anything else that doesn't look good.

    Excuse me. You're right. I wrote wrong. It's fourth gear.
    If you correct it for me I am very grateful.
    Thanks for the answer

  4. #4
    Advanced Tuner ZeroBoostBuick's Avatar
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    S10_2.5_TCM_T43-1.1.hpt

    That's with the TCC tables fixed for the most part.

    I'll take a look at it again tomorrow morning when I get home from work. I gotta hit the hay now.


  5. #5
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    Quote Originally Posted by ZeroBoostBuick View Post
    S10_2.5_TCM_T43-1.1.hpt

    That's with the TCC tables fixed for the most part.

    I'll take a look at it again tomorrow morning when I get home from work. I gotta hit the hay now.


    Hello friend, I tested your modifications but still does not enter the fourth gear before 120 km / h

  6. #6
    Advanced Tuner ZeroBoostBuick's Avatar
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    I cleaned up the TCC apply/release a little more this morning,..

    S10_2.5_TCM_T43-1.2.hpt

    With out actually driving your car and knowing the RPM's in each gear ( or having the proper scans ), I can't make changes in the TUTD (Tap Up Tap Down) tables to help you with your shift.

    If you have the OEM tune, that would go a long way for me to figure things out.

  7. #7
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    Quote Originally Posted by ZeroBoostBuick View Post
    I cleaned up the TCC apply/release a little more this morning,..

    S10_2.5_TCM_T43-1.2.hpt

    With out actually driving your car and knowing the RPM's in each gear ( or having the proper scans ), I can't make changes in the TUTD (Tap Up Tap Down) tables to help you with your shift.

    If you have the OEM tune, that would go a long way for me to figure things out.

    Here's the OEM tune. This car is heavily modified. The engine is an Ecotec L4 with 204hp that with turbo is with 336hp.
    Attached Files Attached Files

  8. #8
    Advanced Tuner ZeroBoostBuick's Avatar
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    Here is a little update to your tcm tune...

    S10_2.5_TCM_T43-1.4.hpt

    I will work on it some more tomorrow.