Potentiometer

Older throttle sensors use it. It has three wires. Worn tracks cause signal dropouts. Hall-effect sensors have replaced many potentiometers because they do not wear. A sweep test with an oscilloscope shows dropouts clearly. Many potentiometer sensors use a 5-volt reference, a ground and a signal wire. Contact cleaner rarely fixes a worn track for long; replacement is the usual repair.

A wiper moves along a resistance track.

Signal gaps cause erratic behaviour. Contactless sensors are replacing it.