WARNING: This page is about a different car, the 1995 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Test numbers refer to numbers on diagnostic chart.
Checks ability of the PCM to command pressure control solenoid.
Checks for voltage at PCM.
Fig 1: Code 73 Schematic (Corvette) Pressure Control Solenoid