Throttle Body: Description and Operation

THROTTLE BODY ASSEMBLY

The throttle assembly contains the following components:
^ The throttle blade
^ The throttle actuator motor
^ The throttle position (TP) sensor 1 and 2

The throttle body functions similar to a conventional throttle body with the following exceptions:
^ An electric motor opens and closes the throttle valve.
^ The throttle blade is spring loaded in both directions and the default position is slightly open.
^ There are 2 individual TP sensors within the throttle body assembly.

The TP sensors are used to determine the throttle plate angle. The TP sensors provide the engine control module (ECM) with a signal voltage proportional to throttle plate movement. The TP sensor 1 signal voltage at closed throttle is above 4 volts and decreases as the throttle plate is opened. The TP sensor 2 signal voltage at closed throttle is below 1 volt and increases as the throttle plate is opened.