Power Steering Pressure Switch: Description and Operation
Pressure SwitchWhen hydraulic pressure reaches 3650 ± 350 kPa (530 ± 50 psi), the pressure switch of the power steering pump closes causing the Powertrain Control Module (PCM) to actuate the idle air control valve, which increases the engine rpm to prevent the overload-induced engine speed slow down. The switch opens when hydraulic pressure drops to 3150 ± 350 kPa (460 ± 50 psi).