To replace the park/neutral position switch from a 4l80-e automatic transmission, one would have first applied the parking brake and shifted the transmission to neutral. Lift up the vehicle and remove the nut holding the transmission control lever in place with the manual shaft and remove the control lever. Important: remove the connector of the wiring harness at a location close to the vehicle harness to prevent breaking the panel neutral position switch lead connector. Then, pull out the wiring harness connector, remove the two screws that hold the park/neutral position switch to the trans, and remove the switch from the manuel shaft. Alternatively in case the switch does not slide off easily, file the outer edge of the manual shaft in order to eliminate burrs on it. For installation, align the switch hub flats with the manual shaft flats and install the switch until the mounting bracket contacted the transmission bosses. Tighten up to two bolts without making them tight. Place the j 41364-a park neutral switch aligner (J 41364-A) onto the switch, with the correct alignment of the slots and the tabs on the tool. Rotate the tool to allow the upper locator pin to go into the slot in the switch, tighten the bolts to 25 nm (18 ft. Lbs.), 25 nm). Delete the j 41364-a, reconnect the vehicle wire harness, and reinstall the transmission control lever with the nut, ensuring a compression of 25 nm (18 ft. Lbs.). Reduce the vehicles and examine that switch work effectively, that the engine starts once the car is in the p (Park) or n (Neutral) positions. If the switch is not being operated as intended, make the necessary changes.