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

What about the obd code?

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.