Throttle Body: Description and Operation

The throttle body controls air flow to the engine. The throttle position is controlled by an accelerator cable and a throttle control lever. The throttle body is a single-piece die casting made of aluminum. It is fitted with an idle switch and Throttle Position (TP) sensor. The idle switch sends a signal to the Powertrain Control Module (PCM) informing the PCM of the vehicle idle conditions. The TP sensor sends a varying signal to the PCM. The PCM uses the signal to measure throttle valve angle and adjust the air/fuel mixture.