COMPUSHIFT Mini Manual – COMPUSHIFT Mini Manual
Tuning and Driving
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On the Chrysler A518/46RH and Chrysler A618/47RH, this screen shows the status of the 4th gear / overdrive
solenoid.
Pressing "select" again exits.
3.2.5 Torque Converter Clutch
This screen shows whether or not the torque converter clutch is engaged.
TCC
When you press the "select" button, the torque converter clutch status is shown continuously.
ON
Pressing "select" again exits.
3.3 Torque Converter Clutch Parameters (GM)
3.3.1 Introduction
The torque converter is hydraulic coupling that trades slippage for torque multiplication, effectively providing an
additional spread of gear ratios for drive-off, acceleration, and passing.
The torque converter clutch locks all of the elements of the torque converter together, preventing slippage and
losses in the torque converter when isn't needed.
This improves fuel economy, reduces engine speed, and builds less heat in the transmission.
Here are the basic rules used for controlling the torque converter clutch or "TCC":
The most important considerations for deciding when to lock and unlock the TCC are vehicle speed and
engine load / throttle.
At lower speeds and higher loads, the torque converter should be active, so the clutch should be unlocked to
allow torque multiplication.
At higher speeds and lower loads, the torque converter isn't needed, so the clutch should be locked to
improve efficiency.
The torque converter helps absorb shift shock, so the torque converter clutch should be unlocked during
shifting.
The torque converter clutch shouldn't lock too soon after a shift completes.
For simplicity sake, the torque converter clutch is only engaged in 4th gear.
The parameters below take these factors into account and allow you to tune for your engine and vehicle.
The drawing below illustrates the relationship between throttle, speed, and the torque converter clutch control
parameters.