p0521
Moderate
GMC · SUVs
Oil Pressure Switch Range/Performance
Quick Answer
Error code P0521 on your GMC SUVs means: Oil Pressure Switch 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
Inspect oil pressure switch wiring
3
Test oil pressure with gauge
4
Change oil and filter
5
Replace pressure switch if needed
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 pressure switch
Engine oil
Oil filter
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