Throttle Full Close Switch: Description and Operation

Closed Throttle (Idle) Position Switch Circuit:

PURPOSE
The Engine Control Module (ECM) controls idle speed through the idle speed servo based on this switch input.

OPERATION
The Closed Throttle Position Switch--an integral part of the TPS--is a contact type switch used by the ECM to detect accelerator operation.
- The ECM applies a voltage to the closed throttle position switch.
- When the throttle valve is in the idle position, the switch contacts should be closed.
- When the accelerator pedal is released the closed throttle position switch is closed. This causes switch output voltage to go low.