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Thread: d2903 factory set at 10?

  1. #21
    Joe (Moderator) joecar's Avatar
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    Quote Originally Posted by Ritch View Post
    TCC does freeup when I let off the thottle. I wish it wouldn't.
    The 2001/2002 F-car (Camaro/Firebird) files will keep the TCC locked when throttle is released (and MPH is above TCC Release curve)...

    If your PCM is compatible with either of these, then try flashing one of these in (you will need to copy all your tables over by hand):
    - OS 12202088 from 2001 F-car with A4,
    - OS 12212156 from 2002 F-car with A4.

    First copy all your tables over to the F-car file, then do a full flash.

  2. #22
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    Yep, only car OSs can keep the TC locked with 0% TPS. Same goes for E67s so I assume E40 and E38s follow suit. But you can flash a car OS in, Im going to play with that this summer when I have a chance.
    ~Erik~
    2013 Sonic RS Manual - 1.4L I4T E78, tuned, turbo mods, etc.
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  3. #23
    Joe (Moderator) joecar's Avatar
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    Quote Originally Posted by joecar View Post
    ...
    Remove the following pids (they don't tell us anything):
    - TRQTRANS,
    - SHIFT32,
    - MFCSTAT,
    - MFABNORMAL,
    - TSHIFT.
    ...
    Since your log indicates the MAF has failed (SD mode), you can also delete MFTOTAL (since misfire detection doesn't operate when MAF is failed).

  4. #24
    Member Ritch's Avatar
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    pc valve was turned down a little, last time the tranny got rebuilt. I think the accumulator springs were changed with Trans-go.

    Thanks for the tip about no misfire with SD. I actually thought I might have a lo rpm miss, but trusted the ecm to tell me about it.

    I can't remember why I have not switched to the car OS.

    test/tune run
    Attached Files Attached Files
    Last edited by Ritch; April 8th, 2010 at 03:19 PM. Reason: tune and log added
    ____________________________
    1999 GMC, rcsb, 2wd, 5.3, XR275HR-12
    Radix magnacharger mp112
    Long tubes true duals, $L60E

  5. #25
    Member Ritch's Avatar
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    as long as I keep TCC above 35% the torque won't slip.

    Joe in SD you say misfire detection in disabled. Is that true for "rough road" TCC release still active? or is that the same thing?

    obvious intentional slip at the end of this log
    Attached Files Attached Files
    ____________________________
    1999 GMC, rcsb, 2wd, 5.3, XR275HR-12
    Radix magnacharger mp112
    Long tubes true duals, $L60E

  6. #26
    Joe (Moderator) joecar's Avatar
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    Quote Originally Posted by Ritch View Post
    ...
    Joe in SD you say misfire detection in disabled. Is that true for "rough road" TCC release still active? or is that the same thing?
    ...
    Ritch,

    This is what I read in the service manual...

    Misfire Monitor Diagnostic Operation

    The misfire monitor diagnostic is based on crankshaft rotational velocity (reference period) variations. The PCM determines crankshaft rotational velocity using the crankshaft position sensor and camshaft position sensor. When a cylinder misfires the crankshaft slows down momentarily. By monitoring the crankshaft and camshaft position sensor signals, the PCM can calculate when a misfire occurs.
    For a non-catalyst damaging misfire, the diagnostic is required to monitor a misfire present for between 1000-3200 engine revolutions.
    For catalyst damage misfire, the diagnostic responds to the misfire within 200 engine revolutions.
    Rough roads may cause false misfire detection. A rough road applies sudden torque variations to the drive wheels and drivetrain. This torque can intermittently decrease the crankshaft rotational velocity. The ABS system detects uneven speed between the vehicles wheels and sends data via the serial data bus to the PCM to disable the misfire monitor until the rough road is no longer detected.
    On automatic transmission equipped vehicles, the Torque Converter Clutch (TCC) will disable whenever a misfire is detected. Disabling the TCC isolates the engine from the rest of the drive line and minimizes the effect of the drive wheel inputs on crankshaft rotation.
    When the TCC is disabled as a result of misfire detection, the TCC will re-enabled after approximately 3200 engine revolutions if no misfire is detected. The TCC remains disabled whenever the misfire is detected, with or without a DTC set. This allows the misfire diagnostic to reevaluate the system.
    (I wonder how many man-years GM spend developing this distributed algorithm, that required some major R&D)


    The misfire monitor is disabled when rough road is detected... so misfires cannot be detected... so the TCC won't be disabled (since no misfires are detected)... that's my simplistic understanding of it...
    TSTATE09 or TSTATE10 mentions "TCC off due to misfire", and I don't see any flags for rough road... so it's hard to tell when the PCM is aware of rough road.

  7. #27
    Joe (Moderator) joecar's Avatar
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    I see in your log when TCCDC is below 35% that slip appears and has a ripple to it.

    Good log, thanks for posting.

  8. #28
    Member Ritch's Avatar
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    Thank you Joe

    One day, I'll have to pay some more money and upgrade EFIlive so I can change OS.
    ____________________________
    1999 GMC, rcsb, 2wd, 5.3, XR275HR-12
    Radix magnacharger mp112
    Long tubes true duals, $L60E

  9. #29
    Joe (Moderator) joecar's Avatar
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    You're welcome...

    To upgrade a V1-Personal to V1-Commercial is $50... see here.

    The Commercial lets you do full flash (i.e. so you can flash the OS).

  10. #30
    Member Ritch's Avatar
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    One more thing,

    Will my PCM accept the new OS? It appears to be the 3 plug device. Picture attatched.

    Rich
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    ____________________________
    1999 GMC, rcsb, 2wd, 5.3, XR275HR-12
    Radix magnacharger mp112
    Long tubes true duals, $L60E

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