Low engine oil level or oil that is badly diluted or the wrong grade; Faulty oil pressure sensor or switch; Damaged wiring, short to earth or corroded connector in the sensor circuit; Genuinely low oil pressure from a worn oil pump, blocked oil pickup strainer or pressure relief valve stuck open; Worn engine bearings causing a loss of oil pressure; Oil leak at the sensor seal or oil gallery; Fault in the engine control unit.

P0522

Engine Oil Pressure Sensor/Switch A Low.

Generic
Powertrain
Generic code
High severity

How this code is built

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

What it means

P0522 means the engine control unit has seen a signal from the engine oil pressure sensor or switch (circuit A) that is lower than expected. This can be caused by genuinely low oil pressure, or by a fault in the sensor, wiring or connector that makes the signal read low. The code is set when the voltage stays below the expected range for the engine speed and conditions.

Symptoms

Oil pressure warning light on the dashboard
Oil pressure gauge reading low or dropping to zero
Engine check light on
Ticking, rattling or knocking noises from the engine
Warning message on the dash or reduced engine performance on some models
Intermittent warning that comes and goes with engine speed or temperature

Possible causes

Low engine oil level or oil that is badly diluted or the wrong gradelikely
Faulty oil pressure sensor or switchlikely
Damaged wiring, short to earth or corroded connector in the sensor circuitlikely
Genuinely low oil pressure from a worn oil pump, blocked oil pickup strainer or pressure relief valve stuck openpossible
Worn engine bearings causing a loss of oil pressurepossible
Oil leak at the sensor seal or oil gallerypossible
Fault in the engine control unitrare

How to diagnose

Read the stored codes and freeze frame data to see engine speed, temperature and load when the fault was set, and check for related codes.
Check the oil level on the dipstick on level ground and look at the oil condition for fuel dilution, sludge or an incorrect grade.
Look for oil leaks around the sensor, filter and sump, and inspect the sensor wiring and connector for chafing, oil contamination, corrosion or poor pin tension.
Check the sensor circuit for supply, signal and earth with a multimeter, and look for a short to earth in the signal wire, following the wiring diagram for the model.
With the engine safely warm, compare the live oil pressure data against the real pressure measured with a mechanical gauge fitted in place of the sensor.
If the mechanical pressure is correct, test or swap in a known-good sensor to confirm it is the fault.
If the pressure is genuinely low, inspect the oil pump, pickup strainer, relief valve and bearing condition, following the manufacturer procedure for that engine.

How to fix

Top up or change the oil and filter with the correct grade and specification, and fix the cause of any fuel or coolant dilution.
Replace the oil pressure sensor or switch and its seal if it is faulty or leaking.
Repair or replace damaged wiring and clean or replace the connector.
Replace the oil pump, pickup strainer or relief valve if the pressure is proven to be low.
Carry out engine repair or rebuild if worn bearings are the cause of the low pressure.

Can I keep driving?

High severity

Do not keep driving until the oil level is checked, as genuine low oil pressure can quickly destroy the engine. If the oil level is correct and the pressure is proven fine, the fault is likely electrical and the car can be driven gently to a garage, but stop at once if the oil warning light stays on or you hear engine noises.

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