DTC P0551: Power Steering Pressure Switch Circuit Range/Performance: Description

The power steering pressure switch converts the existence of a power steering load into a high/low voltage, and inputs it into the PCM. When the steering wheel is turned, hydraulic pressure rises. The power steering pressure switch closes, and the applied battery voltage will be grounded. With this, the power steering pressure switch output voltage will fluctuate between 12 and zero volts. While driving with the steering wheel held straight, the power steering pressure switch turns OFF. The PCM checks whether the power steering pressure switch turns OFF or ON during driving.