Results of Incorrect Operation

An open boost control solenoid driver circuit, ignition feed circuit, or boost control solenoid valve stuck open will cause reduced engine power, especially during wide open throttle operation.

The boost control solenoid driver circuit shorted to ground, boost control solenoid valve stuck closed or a restriction in the boost source or signal hoses will cause full boost to be commanded at all times and a possible overboost condition during high engine load situations.

A restriction in the vacuum signal hose to the bypass valve actuator or a stuck closed bypass valve will cause a rough idle and reduced fuel economy.