Faulty power steering pressure sensor or switch giving a low or no signal; Corroded, loose or damaged sensor connector; Signal wire shorted to earth or chafed against bodywork or the engine; Open circuit or high resistance in the supply or reference wire; Low power steering fluid level or air in the system affecting pressure readings; Fault inside the engine control unit input circuit.

P0552

Power Steering Pressure Sensor/Switch Circuit Low.

Generic
Powertrain
Generic code
Low severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
5: AreaVehicle speed, idle control and auxiliary inputs
52: FaultThe specific fault in that area

What it means

P0552 means the engine control unit has seen the signal from the power steering pressure sensor or switch circuit sitting lower than expected, typically close to zero volts or an open circuit. The ECU uses this input to raise idle speed or compensate for engine load when the steering is turned hard, so a low signal usually points to a wiring, connector or sensor fault.

Symptoms

Malfunction indicator lamp on
Idle speed dips or stalls when turning the steering at parking speeds
Rough or unstable idle with the steering on full lock
Idle speed does not rise when the steering is turned
Occasional power steering warning lamp on some vehicles

Possible causes

Faulty power steering pressure sensor or switch giving a low or no signallikely
Corroded, loose or damaged sensor connectorlikely
Signal wire shorted to earth or chafed against bodywork or the enginepossible
Open circuit or high resistance in the supply or reference wirepossible
Low power steering fluid level or air in the system affecting pressure readingspossible
Fault inside the engine control unit input circuitrare

How to diagnose

Read the stored codes and freeze frame data to see engine speed, load and conditions when the fault set, and note any other codes
Check the power steering fluid level and condition, and look for leaks around the pump, hoses and rack
Inspect the sensor connector and the wiring back along the loom for damage, chafing, corrosion and water ingress
Watch the live data for the power steering sensor or switch while turning the steering slowly from lock to lock, and compare the reading with the manufacturer's specification
Check the sensor reference voltage and earth at the connector with a multimeter
Test the signal wire for a short to earth and for continuity back to the ECU with the connector unplugged and the battery disconnected
Swap in a known good sensor or check its resistance or output against the model-specific procedure, as sensor type varies by vehicle

How to fix

Repair or replace damaged wiring and chafed loom sections, securing them clear of hot or moving parts
Clean or replace corroded or loose connector terminals and reseat the plug
Replace the power steering pressure sensor or switch if its output is out of specification
Top up or correct the power steering fluid, bleed the system and repair any leaks
Repair or replace the engine control unit only after wiring and sensor faults have been ruled out, following the manufacturer's procedure

Can I keep driving?

Low severity

The car can normally be driven, but expect idle dips or stalling when steering at low speed, which can be awkward in car parks or junctions. Book it in soon, and stop if the steering becomes heavy or the engine stalls repeatedly.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.