21. TCM Self-diagnosis Does Not Activate (PNP, Overdrive Control and Throttle Position Switches Circuit Checks): Description

WARNING: This page is about a different car, the 2002 Nissan Sentra. However, it is still accessible from the selected car via links, so may be relevant.

PNP switch
The PNP switch assembly includes a transmission range switch. The transmission range switch detects the selector lever position and sends a signal to the TCM.
Overdrive control switch

Fig 1: Locating Overdrive Control Switch
Courtesy of NISSAN MOTOR CO., U.S.A.

Detects the overdrive control switch position (ON or OFF) and sends a signal to the TCM.
Throttle position switch

Fig 2: Locating Throttle Position Sensor Components
Courtesy of NISSAN MOTOR CO., U.S.A.

Consists of a wide open throttle position switch and a closed throttle position switch.

The wide open throttle position switch sends a signal to the TCM when the throttle valve is open at least 1/2 of the full throttle position. The closed throttle position switch sends a signal to the TCM when the throttle valve is fully closed.