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Thread: shifting problem 4l60e

  1. #11
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    no idea about the fluid. i will suck out some next week.

    i see that release occurs when there is a transition from lock to apply. i see instances where it goes directly from lock to apply, however. i have also been thinking that d1004 is wrong at 412 and should be zero or below apply, but then ist set to 412 in the stock tune. d1007 is 100% stock, btw.

    what i would do first is to set d1007 to max from 400nm. but for boost that probably is irrelevant, because torque is higher. well, i was not logging engine torque i dont know where it comes from. is it a calculated value using the ve table as one of the inputs? then it would be based on values you put in there. now its pretty close, engine is rated 480 nm at 4200 rpm. i was logging rwhp on boost and it was a little low but not unrealistic. but maybe that gets calculated from the real acceleration?

    anyway, here is a couple of logs boosted:

    looking at 9.1 at the last two passes, it stays in apply until 5500 and is off in the other. the same in 8.2.

    (at this point im only really interested in the 2-3 shifts. first gear is useless when boosted and second takes me to around 150 kmh, 120 being the speed limit. i dont think the car has been above 4500 rpm in third, since i have it.)

    desired times are zero, so tap (trans. adaptive learning) should be gone, at least i hope so. could i set p0101 to yes and make the trans run at full pressure all the time? didnt you say somewhere that setting shift times to zero and deleting torque reduction would make the shifts "brutal"? well, my shifts are soft, even n/a. under boost the 2-3 shift takes 0.6 sec. (measured from highes to lowest rpm, disregarding what actually happens in the trans).
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    Last edited by dian; June 9th, 2017 at 05:13 AM.

  2. #12
    Joe (Moderator) joecar's Avatar
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    1000 Nm (730 ftlb) requires a specially built 4L60E or 4L80E and a multi-disc TCC.

    The line pressure would need to be increased by mechanical means in the special build.

  3. #13
    Joe (Moderator) joecar's Avatar
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    TCCSLIP is meaningful only when TCCMODE indicates Locked

    ( when not Locked, the slip may not be updated properly, especially with the 4L60E which has no ISS sensor )


    Negative slip means the transmission is going faster than engine... which is interesting as you have noted.


    Yes, avoid locking the TCC at high throttle (say above 80% TP).

  4. #14
    Joe (Moderator) joecar's Avatar
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    Set D1004 to a large (un-achievable value) below D1001.

    TRQENG is calculated by PCM based on dynair and spark.

    RWHP is calculated from vehicle mass and change in VSS.


    Have you scaled VE/IFR...? If so then trans line pressure will be low... you can mechanically increase pressure by turning set screw on PCS say 1/8 th turn (mark it first).

    Do you have a 300 psi pressure gauge to monitor the line tap on the side of the trans...?

    Yes, shifts should be very firm and quick (should chirp and/or break tyre traction)... try setting shift times to 0.2 second.

  5. #15
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    you mean to set shift times to 0.2 from 0? d1001/4 are at 412. so i set d1004 to 411?

    what is iss? tis is larger than engine rpm during a pull. what do you make of that? o.k. iss = input shaft sensor? there is none? you made my day. so i dont worry about that anymore if its not there, right?

    the real question is: how do i keep tcc off at all times? (i have read a lot of stuff and my head is spinning. a lot of controversial info too.)
    Last edited by dian; October 16th, 2017 at 04:54 PM.

  6. #16
    Joe (Moderator) joecar's Avatar
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    Set D1004 to be lower than D1001 (not equal and not higher).

    4L60E does not have input speed sensor (iss)... so in this case the PCM calculates TIS... so TIS only makes sense while the TCC is locked.

    To keep TCC off simply set the apply curves to unachieveable speeds...

    but TC generates a lot of heat while TCC is unlocked, you will need a bigger trans fluid cooler.


    ~ posted by phone ~
    Last edited by joecar; June 10th, 2017 at 02:27 PM.

  7. #17
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    so in the above tune i moved the 1-2 shift point from 4000 to 5800, set 2. release from 412 to 400, the 1-2 pressure to 600 above 400 nm and the 2-3 pressure to 662 above 400 nm. car went a little sideways during the 1-2 shift but 2-3 was not much different. tcc is unlocked and applies around 5300 in first and stays there during the shift and untill 5400 in second. in the x7 log in appied at 3600 and went off at 5800. so i dont know. it should not apply in second and in no gear at wot. since there is no table for first, i have to assume it never applies in first but it does. i have been reading on here and on other forums and everybody sais the same, work with the tp/speed tables.

    i logged tccdc and its either 0 or 100 as expected but it has no correlation with tc mode. cant logg tccp.

    either the logging is not correct or the trans is crazy. im tempted to wire the brake switch to see what will happen. thats the only way i can think of to gain controll over the tcc. its doing what it wants.

    btw, i cant feel the tcc engaging and have yet to experience a chirp from the tires (275/49718). the fact that a lot of members complain about harsh shifts really gets me.

    edit: i worked my way to h0102 (outputshaft revs per km). its 11.6953 in the tune. its different by 8% in the original tune and again that much off the other way in a 99 c5 tune i found. where do the fractions come from. mine is pretty close with 2.065 m per tire rev.

    its dawning on me that the tc might be locked all the time exept at idle (tccdc) and tcmode is a ghost reading. is that possible?
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    Last edited by dian; June 11th, 2017 at 07:17 PM.

  8. #18
    Joe (Moderator) joecar's Avatar
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    Quote Originally Posted by dian View Post
    ...

    its dawning on me that the tc might be locked all the time exept at idle (tccdc) and tcmode is a ghost reading. is that possible?
    Possibly...

    I'm thinking about how to diagnose this...

  9. #19
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    here is another logg, if somebody wants to have fun and study that. you see me stepping on the brake, like frames 3500-4000. tcc unlocks.

    (the forum seems to have changed into an "ask joe platform" now.)
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  10. #20
    Joe (Moderator) joecar's Avatar
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    ( lol, I'm an intense car guy )

    I'm looking thru your log... I'm analyzing the ratio of TIS:TOS, RPM:TOS and RPM:TIS

    ( see attached calc_pids.txt, rename it to C:\users\<you>\Documents\EFILive\V7.5\User Configuration\calc_pids.txt ).


    For next log:
    - remove the pid GM.TCCP (this is not for 4L60E/4L80E)(it gives strange values)
    - add the pid GM.BOXRATIO
    Attached Files Attached Files

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