Power Steering Pressure Switch: Description and Operation

The Power Steering Pressure (PSP) switch closes when the hydraulic pressure reaches 3920 ± 690 kPa (570 ± 100 psi). This causes the PCM to actuate the idle air control valve in order to prevent the additional load from slowing down the engine. The switch opens when the hydraulic pressure drops to 2970 ± 560 kPa (430 ± 80 psi).