Transmission Position Sensor/Switch: Testing and Inspection

Fig. 008 - WIRING DIAGRAM for Chart C-1A Park/Neutral Switch. VIN 9:

CHART C-1A, PARK/NEUTRAL SWITCH

The Park/Neutral Switch is closed to ground in Park or Neutral and open in other ranges. The ECM supplies 12 volts through an internal resistor to CKT 434 and senses that the switch, is closed when the voltage at terminal B-10 drops to less than 1 volt.

Fig. 007 - Chart C-1A - Park/Neutral Switch:

1. Checks for switch closing in the P/N position. This is indicated by low voltage on CKT 434.
2. Checks to see that voltage increases in D/R range. Checks for open or ground in circuit 434 or misadjusted switch.
3. Checks for faulty wiring to ECM or faulty ECM itself. If voltage is present, it means wiring and ECM are OK.
4. Checks for an open ground circuit, a defective or misadjusted switch, or an open CKT 434.
5. Checking the voltage signal on the ECM side of the switch determines if the switch or CKT 434 is at fault.