Closed Throttle Position (CTP) Switch

CTP switch is located in a common housing with the TP sensor on the bottom of the throttle housing. See Fig 1 . CTP switch closes at about 1.5 degrees before primary throttle plates close. When CTP switch is closed, a ground signal is supplied to PCM. PCM uses this ground signal to activate the following functions:

• Idle stabilization.
• Deceleration fuel shut-off with engine warm and engine speed greater than 1500 RPM. Fuel supply is reactivated when engine speed falls to less than 1200 RPM.
• Special ignition map for deceleration.

Fig 1: Locating Closed Throttle Position (CTP) Switch (A4)

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