Ford
Type:
    Powertrain - Vehicle Speed, Idle Control, and Auxiliary Inputs - ISO/SAE Controlled
Description:
    PSP Sensor Circuit Low Conditions
Cause:
    Engine running, then the PCM detected an open or short to ground condition in the sensor circuit

Generic
Type:
    Powertrain - Vehicle Speed, Idle Control, and Auxiliary Inputs - ISO/SAE Controlled
Description:
    Power Steering Pressure Sensor/Switch Circuit Low