DTC P1743: Torque Converter Clutch Control Solenoid Circuit Fault: Description
WARNING: This page is about a different car, the 2002 Mazda Millenia and 2001 Mazda Millenia. However, it is still accessible from the selected car via links, so may be relevant.
DTC will set if PCM detects TCC control solenoid voltage is remaining at battery voltage, or zero volts after engine is started, PCM determines that TCC control solenoid circuit has a malfunction.