Faulty engine oil pressure sensor or switch sending an incorrect low voltage signal.; Damaged or corroded wiring harness or connector at the oil pressure sensor.; Short to ground in the signal circuit between the sensor and the ECM.; Low engine oil level or degraded oil causing actual low oil pressure, which may trigger the code indirectly.; Malfunctioning oil pump or pressure relief valve leading to genuinely low oil pressure.; ECM software issue or internal fault incorrectly interpreting the sensor signal.; Contaminated or clogged oil pressure sensor port preventing accurate pressure reading.

DTC codes / P05xx · Vehicle speed, idle control and auxiliary inputs / P0522

P0522Engine Oil Pressure Sensor/Switch Circuit Low Voltage

Q: What does code P0522 mean?

Engine Oil Pressure Sensor/Switch Circuit Low Voltage. P0522 means the engine control module (ECM) has detected a low voltage signal on the engine oil pressure sensor circuit, typically below the expected range for the current engine conditions. The ECM compares the sensor's output to a calculated model and flags this code when the signal stays too low for a set period, indicating a possible short to ground, faulty sensor, or wiring issue.

P0522 means the engine control module (ECM) has detected a low voltage signal on the engine oil pressure sensor circuit, typically below the expected range for the current engine conditions. The ECM compares the sensor's output to a calculated model and flags this code when the signal stays too low for a set period, indicating a possible short to ground, faulty sensor, or wiring issue.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaVehicle speed, idle control and auxiliary inputs

Symptoms you may notice

Illumination of the oil pressure warning light or check engine light on the dashboard.
Oil pressure gauge may read low or stay at zero even when the engine is running.
A warning message on the driver information center stating low oil pressure.
Engine may enter limp mode or reduced power mode as a protective measure.
Often no symptoms besides the warning light, especially if the sensor is only slightly out of range.
In rare cases, unusual engine noises or performance issues if actual oil pressure is genuinely low.

Common causes, most likely first

Faulty engine oil pressure sensor or switch sending an incorrect low voltage signal.
Damaged or corroded wiring harness or connector at the oil pressure sensor.
Short to ground in the signal circuit between the sensor and the ECM.
Low engine oil level or degraded oil causing actual low oil pressure, which may trigger the code indirectly.
Malfunctioning oil pump or pressure relief valve leading to genuinely low oil pressure.
ECM software issue or internal fault incorrectly interpreting the sensor signal.
Contaminated or clogged oil pressure sensor port preventing accurate pressure reading.

How to diagnose and fix it

Check engine oil level and condition; top off or change oil if necessary.
Inspect the oil pressure sensor connector and wiring for damage, corrosion, or loose pins.
Use a scan tool to view live oil pressure sensor voltage and compare to specifications.
Perform a voltage drop test on the sensor signal circuit to check for excessive resistance or short to ground.
Test the oil pressure sensor with a mechanical gauge to verify actual oil pressure versus sensor reading.
Replace the oil pressure sensor if testing confirms it is faulty.
Repair or replace damaged wiring or connectors as needed, then clear codes and verify repair.

Don't Assume the Sensor Is Bad

A low voltage code often results from a short to ground in the wiring, not a failed sensor, so always inspect the harness before replacing parts.
Genuinely low oil pressure from a worn oil pump or low oil level can set this code, so verify actual pressure with a mechanical gauge.
Some vehicles use the oil pressure switch for variable valve timing or cylinder deactivation, and a faulty switch can cause drivability issues beyond a warning light.
Corrosion inside the sensor connector is a common cause that is easily overlooked during visual inspection.
After repairs, the ECM may require a relearn procedure or several drive cycles before the code clears permanently.

Can I keep driving with P0522?

If the oil pressure warning light is on, stop driving immediately and check the oil level; continuing to drive with low oil pressure can cause severe engine damage. If only the check engine light is on and the engine runs normally, you can drive cautiously to a repair shop, but avoid heavy loads and high speeds.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.