To check the Park/Neutral switch, first, ensure that it prevents the engine from starting in any gear other than Park or Neutral. Raise the vehicle and securely place it on jack stands, then unplug the electrical connector from the Park/Neutral switch. Use an ohmmeter to check continuity across the indicated switch terminals. There should be continuity with the shift lever in Park or Neutral, and no continuity in any other position. If the switch doesn't operate as described, try adjusting it before retesting, and if it still fails, replace it. For removal, apply the parking brake, place the shift lever in Neutral, disconnect the battery cable, raise the vehicle on jack stands, remove the nut and manual lever, unplug the electrical connector from the switch, and remove the switch retaining bolts. Slide the switch off the manual shaft. Installation involves using a special adjustment tool, aligning the switch with the manual shaft flats, sliding it onto the manual shaft, and securing it with mounting bolts. Remove the adjustment tool and complete the remaining installation steps, tightening the manual lever retaining nut to the specified torque.