Throttle Body: Description and Operation

THROTTLE BODY ASSEMBLY

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

The throttle body functions are 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.

GTP sensors are sensors 1 and 2 are potentiometer type sensors, they 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 near the 5-Volt reference voltage and decreases as the throttle plate is opened. The TP sensor 2 signal voltage at closed throttle is near the low reference voltage and increases as the throttle plate is opened. Each TP sensor has a signal circuit and they both share a 5-Volt reference and a low reference circuits.