Throttle Body: Description and Operation

Throttle Body Vacuum Ports:

Throttle Body Assembly - Exploded View:

Construction
The throttle body unit is comprised of dual (twin) throttle valves which control the amount of air to the engine. The Throttle Position (TP) sensor and Idle Speed Control (ISC) motor are mounted on the throttle body unit.

Vacuum Ports
The throttle body contains ports located at, above, or below the throttle valve. These ports: 1) Generate the vacuum signal for the transaxle vacuum modulator, the fuel pressure regulator, the Tank Pressure Control Valve (TPCV) and the MAP sensor and; 2) Provide vacuum to purge the EVAP system, vacuum brake booster, cruise control servo, parking brake, EGR, air conditioner, and [1][2]PCV