K 1500 Truck 4WD V6-262 4.3L (1991)
Torque Converter Clutch Solenoid: Description and Operation
The purpose of the Transmission Converter Clutch (TCC) feature is to eliminate the power loss of the torque converter stage when the vehicle is in a
cruise mode. The Torque Converter Clutch System uses a solenoid operated valve to couple the engine flywheel to the output shaft of the transmission
through the torque converter. This reduces the slippage losses in the converter, which increases fuel economy. For the converter clutch to apply, two
conditions must be met.
1. Internal transmission fluid pressure must be correct.
2. The ECM completes a ground circuit to energize the TCC solenoid in the transmission, which moves a check ball in the fluid line. This allows the
converter clutch to apply, if the hydraulic pressure is correct.
