Vehicles equipped with automatic transmissions use a Torque Converter Clutch (TCC) between the engine and transmission. In this way, greater torque output from the engine and steering of the rear wheels is achieved. Both the engine and the transmission are connected by a fluid coupling mechanism system, which multiplies the torque resulting in the actual engine RPM and the input RPM of the transmission having a difference of at least 10 %.
Fault code P0742 OBDII is set when the TCM (Transmission Control Module) or PCM (Powertrain Control Module) detects a fault in the circuit that operates the TCC solenoid.