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How do you tune 6L80 torque converter lockup behavior?

The controls (HP Tuners, GM TCMs):

  • Apply/release speed tables exist for each mode (Normal, Cruise, Performance, Hot, 4WD Low, Tap Up/Down) plus WOT schedules. They're indexed by throttle position and gear.
  • TCC Release TPS sets how much throttle unlocks the converter at a given speed and gear.
  • Max/min duty-cycle tables vary with line pressure and fluid temperature.
  • Lock during shift keeps the converter locked across a shift. HP Tuners describes this as extremely hard on the transmission and converter clutch. Holley's 6L80/90 control has matching lock/unlock-during-shift tables for each gear change, and converter clutch events can also trigger torque requests.

After changes: Holley recommends a transmission relearn (adaptive reset) after any major 6L80/6L90 calibration change, so the TCM relearns clutch fill and shift timing. See transmission tuning.

Want to do it yourself? See who tunes it, and how to learn.

Confidence: medium — sources disagree or are limited; check the sources below.

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