The throttle position sensor (TPS), is an electronic component that helps the engine computer determine the optimal ignition timing and fuel injector. This is done by measuring how open the throttle valve actually is. As a failsafe measure, vehicles with ...

The fault code P0121 is a sign of a problem in your engine’s throttle (TP) position sensor. This code can cause serious problems and your vehicle may not start. The P0121 code is a ‘Throttle/Pedal position sensor “A” circuit range/performance ...