Calais L4-138 2.3L VIN D FI (1990)
Power Steering Pressure Switch: Description and Operation
The Power Steering Pressure Switch (PSPS) closes during high pressure power steering situations. When the power steering switch is closed, power to
the A/C relay is shut off, resulting in air conditioning compressor clutch disengagement. A signal is also sent to the ECM. The ECM uses this signal for
idle control.