DeVille V8-4.9L VIN B (1995)
Power Steering Pressure Switch: Description and Operation
Power Steering Pressure Switch
The Power Steering Pressure Switch (PSPS) is located on the rack and pinion assembly under the ABS hydraulic unit. The power steering pressure
switch is normally closed and provides a battery voltage signal to the Powertrain Control Module (PCM) with no power steering load. When power
steering pressure increases to a calibrated level due to steering load (such as full steering lock), the switch opens and causes the signal voltage to the
PCM to drop to 0 volt.
The PCM uses the power steering pressure switch signal for idle speed control during high steering loads to maintain a stable idle. A shorted power
steering pressure switch may cause a stumble or stall during steering loads and an open switch should set a Diagnostic Trouble Code.
