TCM Self-diagnosis Does Not Activate (PNP, Overdrive Control and Accelerator Pedal Position Sensor Circuit Checks): Description

WARNING: This page is about a different car, the 2003 Nissan Pathfinder. However, it is still accessible from the selected car via links, so may be relevant.

PNP switch
The PNP switch assemble includes a transmission range switch. The transmission range switch detects the selector position and sends a signal to the TCM.
Overdrive control switch
Detects the overdrive control switch position (ON or OFF) and sends a signal to the TCM.
Closed throttle position signal and wide-open throttle position signal
ECM judges throttle opening based on a signal from accelerator pedal position sensor, and sends the signal via CAN communication to TCM.

Fig 1: Identifying PNP Switch - 2WD And 4WD
Courtesy of NISSAN MOTOR CO., U.S.A.

Fig 2: Identifying Overdrive Control Switch
Courtesy of NISSAN MOTOR CO., U.S.A.

Fig 3: Identifying Accelerator Pedal Position Sensor
Courtesy of NISSAN MOTOR CO., U.S.A.