Power Steering Pressure Switch Check

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION

The Power Steering Pressure (PSP) switch is a normally open pressure switch located in the high pressure (outlet) hose of the power steering system. The PCM applies a voltage (about 12.0 Volts) to the sensor. When power steering pressure is low the PSP switch is open and the PCM senses high signal voltage (low engine load). When power steering - pressure is high, such as during parking maneuvers, etc., the PSP switch closes, and the PCM senses low signal voltage (high engine load). The PCM will increase the idle air rate and retard the timing to compensate for the additional load on the engine.

DIAGNOSTIC AIDS

^ A pressure switch that will not close or an open circuit may cause the engine RPM to drop when power steering loads is high.

^ A switch that will not open or the signal circuit shorted to ground may have an adverse effect on idle quality.

^ Inspect all related wiring and connectors including the connections at the PCM. These may cause an intermittent malfunction. Check for damaged, corroded or pushed out terminals.