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Thread: Tcc problems

  1. #1
    Tuner in Training
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    Tcc problems

    Am running tcc wire through relay to power it and brake switch to brake the power.problem is converter not locking up this is a 2002 5.3 swap in 67 firebird. Tcc wire is powered when key hot and not only when brake switch is open.does tcc need power all the time except under braking

  2. #2
    Tuner in Training
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    Lets start by asking what transmission is this?

    If its a 4l60e there's two solenoids that control TCC lockup.

  3. #3
    Tuner in Training
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    it is a 4l60e sorry,i haven't made any changes to the program as far as transmission goes

  4. #4
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    First thing i would start off with is seeing if the ECU is commanding the TCC lockup. Log the PID for TCC lock up in the scanner as well as TCC PWM duty cycle.

    If you're driving down the road and the lockup flag says "yes" then the ECU is commanding lockup.
    Another thing to look at is the TCC PWM duty cycle. From a dead stop it should go from 0% to 90% at about 5 mph or so, then as you approach lockup speed it should drop back to down to 0% then up to 50% and slowly back up to 90% as the converter locks. The TCC PWM solenoid is what actually applies the clutch in the converter and the TCC solenoid

    If all that checks out then the ECU is doing everything it needs to and your problem is else where. I chased a similar problem in my 97 silverado with a 4l60e and it was the TCC solenoid snout was split down the side and would leak apply fluid past it with 12 volts applied.


    Tl:dr isolate the problem, figure out if the ECU is doing what its supposed to and go from there.

  5. #5
    Tuner in Training
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    it seems like everything is working tcc duty cycle goes to 97% tcc applied says yes,little confused though there are 3 tcc applied icons in the scanner.yet I still don't see any rpm change.i was going to attach my scanner reading but haven't figured out how yet lol

  6. #6
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    firebird1.hpl got it

  7. #7
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    My laptop is broken at the moment (3 months old, ASUS quality!) So i cant see the log. If the ECU is saying lock up = yes and duty cycle above 90% then she should be locked up. If not then we know its not a tune related issue.

    Next step is to back probe the TCC solenoid and make sure its getting 12 volts when the TCC lockup = yes. Theres a couple of ways to do this without actually driving around, one way is to use the bidirectional controls in the scanner to force TCC lockup while in park idling. If you're seeing 12 volts at the pins for the TCC lockup then the problem is a hydraulic issue in the transmission.

  8. #8
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    that was the first thing I tried was commanding it on with the scanner while driving and did not function whoever I did not look for any voltage.i picked up a tcc pwm solenoid from my buddy at gm dealer going give that a try

  9. #9
    Tuner in Training
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    Ok but its entirely possible its the TCC solenoid or vavle and not the TCC PWM solenoid or valve