General description
30. The Park/Neutral Position Switch, located on the transmission, provides information to the ECM/PCM when the transmission shift lever is in neutral (parking) position. The computer uses this information to control the transmission torque converter clutch (TCC), the exhaust gas recirculation (EGR) system (on 3.1 l engines) and the operation of the idle air control valve (IAC).
Warning! Do not start the engine with the parking/neutral position sensor disconnected: this will negatively affect the quality of the idle mode, which may lead to the generation of a false code 24 (vehicle speed sensor circuit fault).
31. When the gear shift lever is set to neutral or parking position, the sensor closes to ground, and when the gear is engaged, it opens (see illustrations).
4.31a. Location of the parking/neutral position sensor and its electrical connector on the 3.1L engine |
4.31b. Location of the parking/neutral position sensor and its electrical connector on the 3.8L engine |
32. To check the technical condition of this unit, a special SCAN device is required, therefore, if any faults appear in it, take it for diagnostics to the nearest specialized workshop.
Adjustment
33. To adjust the park/neutral position sensor, place the gear shift lever in the park position.
34. Loosen the casing mounting bolts, after which the rear wall of the casing should rotate on the axis, opening access to the sensor adjustment mechanism.
Replacement
35. Before replacing the sensor, set the gear shift lever to neutral position.
36. Disconnect the electrical connectors.
37. After unscrewing the gear selector lever lock nut, remove the lever from the gearbox.
38. Mark the position of the sensor on the gearbox with paint.
39. After unscrewing the bolts, remove the sensor from the gearbox.
40. Install the notched spacer ring coaxially with the gear selector lever on the gearbox.
41. Press the sensor to engage it with the lever.
42. With the gear shift lever in the park position, adjust the sensor.
43. Connect the electrical connectors.
(The article is reprinted from the website: CHEVYMAN.ru)