Throttle position sensors on the normal fuel injection systems are not adjustable, do not need to be adjusted, and do not magically get out-of-adjustment. If you have the insanely dangerous "throttle-by-wire" system that put Toyota in the news, you do not want to monkey with that yourself. Anyone who touches it will be a party to the future lawsuits which we know are coming.

Regular throttle position sensors set fault codes when their signal voltage goes below 0.5 volt or over 4.5 volts. Usually that occurs from a worn spot in the sensor element itself, but a loose or corroded terminal in the connector, a cut wire, or a corroded splice can cause the same thing. The TPS gets its 5.0 volt supply and ground on common wires that feed other sensors. A corroded splice can set fault codes too.

Answered by caradiodoc (expert)
17,324 answers provided