P1800 Transmission Clutch Interlock Safety Switch Circuit Failure

Possible causes
  • Harness or connectors (The solenoid valve circuit is open or shorted.)
  • VIAS control solenoid valve
    • When is the code detected?
  • An excessively low or high voltage signal is sent to ECM through the valve
    • Symptoms
    – Engine Light ON (or Service Engine Soon Warning Light)
    P1800 Description
    The VIAS control solenoid valve cuts the intake manifold vacuum signal for power valve control. It responds to ON/OFF signals from the ECM. When the solenoid is off, the vacuum signal from the intake manifold is cut. When the ECM sends an ON signal the coil pulls the plunger downward and feeds the vacuum signal to the power valve actuator.
    P1800 Information for specific makes
    P1800 BUICK
    P1800 CADILLAC
    P1800 HYUNDAI
    P1800 NISSAN
    P1800 INFINITI
    P1800 2004 NISSAN QUEST
    P1800 2005 NISSAN QUEST
    P1800 2002 INFINITI I35
    P1800 2003 INFINITI I35
    P1800 2004 INFINITI I35