Engine

P0522 — Engine Oil Pressure Sensor/Switch Circuit Low Voltage

Severity: high Do not drive

What P0522 means

The engine control unit monitors the signal from the oil pressure sensor or switch. P0522 is set when that signal voltage falls below the expected range. The cause may be truly low oil pressure, or a faulty sensor or a wiring short to ground.

Symptoms

  • Oil pressure warning light on
  • Check Engine light on
  • Engine knocking or ticking, especially at idle
  • Oil pressure gauge reads zero or fluctuates
  • False low oil pressure warnings

Possible causes

  1. Low engine oil level
  2. Actual low pressure from a worn oil pump or bearings, or oil that is too thin
  3. Failed oil pressure sensor or switch
  4. Signal wire shorted to ground or damaged harness insulation
  5. Corroded or oil-soaked sensor connector
  6. Clogged oil filter or pickup screen
  7. Rarely, a faulty engine control unit

How to diagnose

  1. Shut the engine off and check the oil level and condition on the dipstick, looking for fuel dilution or wrong viscosity.
  2. Read freeze frame data and compare the scan tool oil pressure reading, if available.
  3. Measure actual oil pressure with a mechanical gauge and compare with factory specs.
  4. Inspect the sensor connector and harness for chafing, oil intrusion and corrosion.
  5. With the sensor unplugged, test the signal wire for a short to ground.
  6. Check sensor supply voltage and ground with a multimeter.
  7. Replace the sensor if mechanical pressure is normal.
  8. If wiring and sensor are good, consider a control unit fault.

Common fixes

  • Top up or change the oil and filter using the correct specification
  • Replace the oil pressure sensor or switch
  • Repair the harness and clear the short to ground
  • Clean or replace the connector
  • Repair the oil pump or engine if low pressure is confirmed

Questions and answers

What does P0522 mean?

The engine computer is getting a signal voltage from the oil pressure sensor that is too low. It can mean truly low oil pressure, or a bad sensor or wiring.

Can I drive with code P0522?

Only after checking the oil level and pressure. If the oil light is on and the engine is noisy, stop and shut it off to avoid severe engine damage.

Is the oil pressure sensor always the problem?

No. Check the oil level and measure real pressure with a gauge first, then inspect wiring. Replace the sensor once pressure is confirmed normal.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.