Throttle Full Close Switch: Description and Operation

Closed Throttle Position (CTP) Switch
The CTP switch detects whether or not the throttle plate is at a closed (idle) position. The CTP switch sends an ON signal to the Powertrain Control Module (PCM) when the the throttle plate is closed. When the throttle plate is open beyond a specified value the CTP switch will send an OFF signal to the PCM. The CPT switch consists of a hall switch integrated circuit, a magnet, and a spring. The CTP switch is located inside of the Throttle Position Sensor (TPS). In order to service the CTP switch the TPS must be replaced.