P0554Power Steering Pressure Sensor/Switch Circuit Intermittent
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- Hydraulic power steering has a pressure switch or sensor on the high-pressure line; when the wheel is turned at standstill, pump pressure and engine load rise sharply, so the engine module raises idle air in advance to stop the engine stalling. That makes it an input to idle control under CARB. Switches (Saab, Mitsubishi) ground a pull-up; analogue 5 V sensors (Toyota) give about 0.45 V at zero pressure. GM's and Ford's tables do not use P0550–P0554. P0554 means the signal flutters. Mitsubishi sets it when the switch changes state at 10 Hz or more for 20 s above 50 km/h – no sound switch switches that fast. Causes are electrical (loose contact) as well as hydraulic: pressure pulsation from air or low fluid, or an unsteady pump.
- What you may notice
- Idle speed jumping or fluctuating
- Check engine light depending on the maker
- Steering pump noise (air, low fluid)
- Likely causes
- LikelyLoose contact or corrosion at connector or wire
- PossibleLow fluid or air in the system (pressure pulsation)
- PossiblePressure switch worn (contact bounce)
- RareSteering pump delivering unsteady pressure
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Easy · Often possible to do yourself.Typical cost: €20 – €250
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.