P0550
Power Steering Pressure Sensor/Switch Circuit
- Severity
- Medium
- Driving
- Drivable — book it in
A fault in the power steering pressure sensor or switch circuit. The module uses this to know when the steering pump is loading the engine, so it can raise the idle speed to compensate.
Possible causes
- CommonFailed power steering pressure sensor or switch
- CommonLow power steering fluid, on a hydraulic system
- CommonCorroded connector or damaged wiring
- PossibleLeaking power steering hose or pump
- PossibleLoss of reference voltage or earth
What you might notice
- Engine stalling or dipping when the steering is turned at low speed
- Rough idle when parking
- Heavy steering
- Whining from the power steering pump
- Check engine light on
What to check, in order
- Check the power steering fluid level and look for leaks. A hydraulic pump low on fluid loads the engine unpredictably and whines while doing it.
- Watch the sensor reading while someone turns the steering from lock to lock with the engine idling - the pressure should rise clearly.
- Inspect the connector for corrosion and fluid contamination.
- Check the reference voltage and earth at the sensor.
- Note what this sensor is for: it tells the module to raise idle speed when the steering pump loads the engine. That is why the symptom is stalling while parking rather than anything to do with the steering itself.
Read this code from your own car
Plug an ELM327 adapter into the OBD-II port under the dashboard. Pin16 reads every stored, pending and permanent code, explains each one like this page does — offline, with no account — and shows what the car recorded when the fault was set.
Where this code sits
P00xxP01xxP02xxP03xxP04xxP05xxP06xxP07xxP08xxP09xxP0AxxP0BxxP0CxxP0DxxP0ExxP0FxxP10xxP11xxP12xxP13xxP14xxP15xxP16xxP17xxP18xxP19xxP1AxxP1BxxP1CxxP1DxxP1ExxP1FxxP20xxP21xxP22xxP23xxP24xxP25xxP26xxP27xxP28xxP29xxP2AxxP2BxxP2CxxP2DxxP2ExxP2FxxP30xxP31xxP32xxP33xxP34xxP35xxP36xxP37xxP38xxP39xxP3AxxP3BxxP3CxxP3DxxP3ExxP3Fxx
Vehicle speed control, idle control and auxiliary inputs
P0500P0501P0502P0503P0504P0505P0506P0507P0508P0509P0510P0511P0512P0513P0514P0515P0516P0517P0518P0519P0520P0521P0522P0523P0524P0525P0526P0527P0528P0529P0530P0531P0532P0533P0534P0535P0536P0537P0538P0539P0540P0541P0542P0543P0544P0545P0546P0547P0548P0549P0550P0551P0552P0553P0554P0555P0556P0557P0558P0559P0560P0561P0562P0563P0564P0565P0566P0567P0568P0569P0570P0571P0572P0573P0574P0575P0576P0577P0578P0579P0580P0581P0582P0583P0584P0585P0586P0587P0588P0589P0590P0591P0592P0593P0594P0595P0596P0597P0598P0599