No announcement yet.

TCC suddenly stopped locking up.

  • Filter
  • Time
  • Show
Clear All
new posts

  • TCC suddenly stopped locking up.

    GM 4L60E. A friend told me his TCC isn't locking up, or when it does, he said it's only when Line Temp exceeds 84°F (unsure of relevance). I've verified in datalogs that he's meeting minimum speeds and TPS to lock it, minimum RPM definitely exceeded, right gear (4th). Is there anything else I may be missing that would prevent it from locking? Datalogs show TCC Duty Cycle at 0% always, but it used to work normally a few weeks ago in previous datalogs.

  • #2
    Maybe something in these forum threads will give you a clue: (Related Forum Thread) (Related Forum Thread)
    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: 385"/6.3L SBF, Dart SHP 8.2 block, forged steel crankshaft & H-beam rods, forged pistons, Trick Flow Twisted Wedge 11R 205 CNC Comp Ported heads, 12:1 compression ratio, 232°-244° duration/.623" lift/114° LSA camshaft, TFS R-Series FTI Comp Ported intake, BBK 80mm throttle body, Holley Dominator MPFI & DIS, Holley 36-1 crank trigger, MSD 1x cam sync, PA PMGR starter, PA 200A 3G alternator, Optima 34/78 Red battery, 100HP progressive dry direct-port NOS, R134a A/C, Spal Dual 12" HP 3168 CFM fans, Frostbite 3-core aluminum radiator, Pypes dual 2.5" exhaust, off-road X-pipe, shorty headers, Earl's -6AN fuel system plumbing, Walbro 255 LPH in-tank pump & Pro-M -6AN hanger, S&W subframe connectors, BMR upper & lower torque box reinforcements, LenTech Strip Terminator wide-ratio Ford AOD, 10" 3000 RPM C6 billet converter, B&M Hammer shifter, Stifflers transmission crossmember & driveshaft safety loop, FPP aluminum driveshaft, FPP 3.31 gears, Cobra Trac-Lok differential, Moser 31 spline axles, '04 Cobra 4-disc brakes, '93 Cobra booster & M/C, 5-lug Bullitt wheels & 245/45R17 M/T Street Comp tires.


    • #3
      Got a GCF tune and a datalog of the issue happening?


      • #4
        Terminator X file here:

        Two datalogs displaying the issue:

        Thank you for taking a look. Any advice is well received.


        • #5
          The information online is conflicting (no surprise), but TCC Lockup commands have either a minimum engine temperature and/or minimum transmission line temperature to activate lockup. So your observed line temperature of 84°F may be correct or it may require an engine coolant temperature of 150°F or 180°F depending on what you read. Here's one example:

          There are some examples I found where driving on a cold day the TCC would be "locked" and then unlock as temperatures drop and these were on unmodified factory systems.

          I don't know what logic Holley uses, but you could try to contact technical support and ask what specific engine or transmission temperatures are used in their system to allow Lockup. You datalogs indeed show that TCC Lockup is never commanded and I can't find any settings in the EFI software that allow a user to change those temperatures.