p0521
Moderate
Cadillac · Sedans
Engine Oil Pressure Sensor/Switch Circuit Range/Performance
Quick Answer
Error code P0521 on your Cadillac Sedans means: Engine Oil Pressure Sensor/Switch Circuit Range/Performance. This is usually fixable — see the step-by-step guide below.
Affected Models
Likely Causes
How to Fix It
1
Check engine oil level and condition
2
Replace oil filter
3
Test oil pressure with mechanical gauge
4
Verify oil pressure sensor output
5
Replace sensor if reading is incorrect
Pro Tip
This fix requires some technical knowledge. If you're unsure about any step, consider contacting support or a qualified technician.
Parts You May Need
Oil filter
Engine oil
Oil pressure sensor
Mechanical pressure gauge
Related Error Codes