Engine Oil Pressure Sensor/Switch A High
What it means
P0523 means the ECM sees an abnormally high voltage from the engine oil pressure sensor/switch circuit. This is an electrical fault in the sensor circuit — it does not by itself mean oil pressure is actually low. The catch is that a faulty sensor makes the oil-pressure gauge or warning unreliable, so it's worth confirming real oil pressure with a mechanical gauge before dismissing it.
Can I keep driving? The engine runs — this is a sensor circuit fault, not proof of low oil pressure. The risk is that you can't trust the oil-pressure gauge/light, so a real pressure problem could go unnoticed. Verify actual pressure and fix promptly.
Common symptoms
What you'll notice
- Check-engine light on
- Inaccurate, pegged-high, or erratic oil-pressure gauge reading
- Oil-pressure warning light may behave incorrectly
- Often no change in how the engine runs
Common causes
Most likely first
- Faulty engine oil pressure sensor/switchLikely
- Open circuit or short-to-power in the sensor wiring (high voltage)Common
- Corroded or loose sensor connectorCommon
- Damaged sensor wiring near the engineLess often
- ECM/PCM fault (rare)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and confirm the code with a scan tool.
- Confirm actual oil pressure with a mechanical gauge before assuming the sensor is at fault.
- Inspect the sensor connector and wiring for an open or short to power.
- Compare the sensor's signal against the expected range for the measured pressure.
- Replace the oil pressure sensor if the wiring is good. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P0523?+
Can I just clear P0523?+
Related codes
Often seen with P0523
Read & clear P0523 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.