Custom Ultrasonic Sensor Schematic
You are obliged to measure all input signals that may affect T+ output on each pin and include is such a question.  Then read the datasheet which ought to be linked for expected inputs.  Then make sense of your issues using Ohm's law for starters.  This is a bipolar charge pump with a level shifting inverter for input voltage.  Start with pin 16, 15, then 2,6 voltages
This is normal debug 101 and how you learn.