Century L4-2.2L VIN 4 (1994)
Park/Neutral Position Switch Wiring Circuit
Circuit Description:
The Park/Neutral Position (PNP) switch contacts are a part of the neutral start/back up switch and are closed in park or neutral, and open in
drive/reverse ranges.
The PCM supplies ignition voltage through a current limiting resistor to CKT 434 and senses a closed switch, when the voltage on CKT 434 drops to
less than one volt.
The PCM uses the PNP signal as one of the inputs to control idle air control and VSS diagnostics.
Chart Test Description: Number(s) below refer to circled number(s) on the diagnostic chart.
1.
Checks for a closed switch to ground in park position. Different makes of scan tools will read PNP switch differently. Refer to tool operations
manual for type of display used.
2.
Checks for an open switch in drive range.
3.
Be sure scan tool indicates drive, even while wiggling shifter to test for an intermittent or misadjusted switch in drive range.
