Home/Lexus/LX/Lexus LX J80 (1995-1997)/Repair manual/Testing & Diagnostics/DTC P1780 - PARK/NEUTRAL POSITION (PNP) SWITCH
Contents Wiring diagrams Section: Testing & Diagnostics All sections

DTC P1780 - PARK/NEUTRAL POSITION (PNP) SWITCH Lexus LX J80

CAUTIONIf ECM replacement is instructed in following testing, always ensure ECM connectors and ground circuit are okay. If either are suspect, repair and repeat testing to confirm ECM malfunction.

Circuit Description

The PNP switch sends a signal to ECM when transmission is in Neutral or Park. This signal is used for air/fuel correction and for idle speed control. DTC is set under 2 conditions

  1. When 2 or more switches are on simultaneously for "N", "2" and "L" position.
  2. ECM is receiving an ON signal from PNP switch when vehicle is being operated for more than 30 seconds at 44 MPH or more (1500-2500 RPM).