Reatta V6-231 3.8L VIN C SFI (1990)
Torque Converter Clutch: Description and Operation
Torque Converter Clutch Solenoid
The Torque Converter Clutch (TCC) is an ECM controlled system that is designed to eliminate power loss (slip) of the transaxle torque converter when
the vehicle is in a cruise mode, thus improving fuel economy. Engagement of the TCC is accomplished by a solenoid operated valve within the transaxle.
The solenoid is activated when an internal switch in the ECM is grounded. Although the ECM may command the TCC "ON," the converter clutch will
not apply until internal transmission fluid pressure requirements are met.
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Vehicle speed and coolant temperature must be above a certain value before the TCC can be applied.
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After the TCC is applied during engine load condition, the ECM uses the information from the TPS to release the clutch when the car is
accelerating or decelerating at a certain rate.
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The transaxle uses a 4th gear discrete switch to signal the ECM when the transaxle is in 4th gear. However, the transaxle need not be in 4th gear
for the ECM to engage the TCC. The ECM will use the 4th gear switch input to determine some of the conditions under which the TCC is applied
or released.