Engine Oil Pressure Sensor/Switch Low Voltage
The Powertrain Control Module (PCM) detected that the voltage signal from the engine oil pressure sensor or switch is lower than the manufacturer's specified minimum threshold. This typically indicates an electrical circuit issue or a faulty sensor, though actual low mechanical oil pressure must be ruled out.
This code should be addressed immediately. While it often points to an electrical fault with the sensor, driving with actual low oil pressure can cause catastrophic engine damage in a very short time.
Common symptoms
- Illuminated Check Engine Light
- Oil pressure warning light illuminated on the dashboard
- Oil pressure gauge reading zero or pegged low (if equipped)
- Engine stalling or shutting off (on vehicles that cut fuel for protection)
- Engine ticking or knocking noises (if actual oil pressure is low)
Likely causes
- Faulty engine oil pressure sensor/switch
- Damaged, shorted, or corroded wiring in the oil pressure sensor circuit
- Poor electrical connection at the oil pressure sensor connector
- Low engine oil level or extremely dirty oil
- Mechanical engine oil pressure issue (e.g., failing oil pump)
- Faulty Powertrain Control Module (PCM) (rare)
What to check before replacing parts
Check the engine oil level and condition using the dipstick.
Look for: Oil level below the minimum mark or oil that is excessively sludgy and dirty, which can affect pressure readings.
Visually inspect the oil pressure sensor, connector, and wiring harness.
Look for: Frayed wires, melted insulation, oil intrusion into the connector, or a loose/corroded connection at the sensor.
Test the oil pressure sensor circuit reference voltage with a multimeter.
Look for: A reference voltage (typically 5V) at the connector with the key on, engine off; if missing, there is a wiring or PCM issue.
Verify actual mechanical oil pressure using a mechanical oil pressure gauge threaded into the engine block.
Look for: Pressure readings that match the manufacturer's specifications, confirming the issue is strictly electrical and not a failing oil pump.
Test the oil pressure sensor resistance or signal output.
Look for: Resistance or voltage values outside the manufacturer's specified range when the engine is running, indicating an internally failed sensor.
This page explains the generic P0522 definition and is general reference information, not a diagnosis for your specific vehicle. Actual causes, severity, and repairs vary by make, model, engine, and mileage — always confirm with a scan tool and a qualified technician before replacing parts.
Gear guide: Best OBD2 ScannersRead this code yourself next time — from $20 Bluetooth dongles to bidirectional scan tools.Rather have a pro handle it? Find a vetted local mechanic.