P1520

DTC P1520 Park/Neutral Position Switch Diagnostic Chart:

Park/Neutral Position Switch Wiring Schematic:

CIRCUIT DESCRIPTION
The Park/Neutral Position (PNP) switch is part of the neutral start switch. The PNP switch contacts are closed to ground in park or neutral and open in drive ranges.

The Powertrain Control Module (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 speed (IAC).
^ Vehicle Speed Sensor (VSS) diagnostics.
^ Spark advance.

DIAGNOSTIC TROUBLE CODE (DTC) P152O WILL SET WHEN
^ Signal on CKT 434 indicates an open PNP switch for 3 consecutive start-ups.

Or

^ Signal on CKT 434 grounded.
^ No DTC P0703.
^ Transmission is in 3rd or 4th gear.
^ Torque Converter Clutch (TCC) is locked.
^ Above conditions are met for 1 second.

DTC P1520 does not illuminate the Malfunction Indicator Lamp (MIL).

DTC CHART TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.
1. Checks for a closed switch in park position.
2. Checks for an open switch in drive range.
3. Be sure Tech 1 scan tool display does not indicate P/N actual "YES," even while wiggling shifter, to test for an intermittent or misadjusted switch in drive or overdrive range.