How to distinguish three-wire and four-wire throttle position sensors

Three-wire potentiometer throttle position sensor: power, signal and ground.

Three-wire, the power supply is 5V from the computer, the signal is the voltage between 0 and 5V generated by the throttle opening, and the ground is the loop, depending on what car it is. Some electronic throttles are hard to find, but the computer can read the faults.