Chart C1A - Park/Neutral Switch Diagnosis (Auto Trans.)
The park/neutral switch is closed to ground in park or neutral, and open in drive ranges. The ECM supplies 12 volts through an internal resistor to circuit No. 434 and senses that switch is closed when voltage at terminal B10 drops to less than one volt.
NOTE:
Test numbers refer to test numbers on diagnostic chart.
- Checks for a closed switch to ground in park position. Different makes of "SCAN" tester will read P/N differently. Refer to "SCAN" tester operations manual for type of display used.
- Checks for an open switch in drive range.
- Be sure "SCAN" tester indicates drive, even while wiggling shifter to test for an intermittent or misadjusted switch in drive range.