Circuit/System Description

The boost gauge is a measure of the engine manifold air pressure. The engine control module (ECM) sends a PWM signal to the boost gauge via the boost gauge signal circuit. The boost gauge displays the engine air intake above and below the ambient manifold pressure. The ECM controls the engine boost pressure with the boost control solenoid. The engine boost system pumps more air than the engine would normally use into the intake manifold. The excess air pumped into the intake manifold, creates the engine boost effect. The maximum boost pressure is about 83 kPa (12 psi). When the ignition is turned ON and the boost gauge is ON, the boost gauge performs a power up self test. The boost gauge dial normally below 0 kPa (0 psi) moves up to 0 kPa (0 psi) to indicate the boost gauge passed the self test. Power is provided to the boost gauge via the ignition 1 voltage circuit.