Circuit Description
The throttle position sensor is mounted in the throttle body and detects the throttle valve opening angle. When the throttle valve is fully closed, a voltage of approximately 0.3 to 0.8 V is applied to terminal VTA of the ECM. The voltage applied to terminal VTA increases in proportion to the opening angle of the throttle valve and becomes approximately 3.2 to 4.9 V when the throttle valve is fully opened. The ECM judges the vehicle driving conditions from this signal input from terminal VTA, and uses it as one of the conditions for controlling the air-fuel ratio, power increase and fuel-cut.
HINT:
After confirming DTC P0120, confirm the throttle valve opening percentage and closed throttle position switch condition using the hand-held tester or the OBD II scan tool. Enter the following manus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL.