Engine Oil Pressure Low
Engine oil pressure is below the acceptable range.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The engine oil pressure sensor is reading a low oil pressure value, which means that the oil isn't circulating properly and could cause engine damage if it continues.
What the computer is actually seeing
The engine control module (ECM) or electronic control unit (ECU) detects that the oil pressure is less than 10 psi when the engine is at normal operating temperature, or it sees a reading significantly below expected values.
What a healthy reading looks like
Oil pressure should be between 25-80 psi at normal operating temperatures (typically around 200°F).
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 11. Check the engine oil level. If it's low, add oil and recheck the code.
- 22. Inspect the oil pressure sensor and wiring for damage or disconnection.
- 33. Confirm the oil pressure reading with a mechanical gauge. If it reads low (less than 25 psi), proceed to the next step.
- 44. Check the oil filter for clogging or restriction.
- 55. Assess the oil pump operation. If the pump isn't functioning properly, it may need replacement.
Common causes
- Low engine oil level
- Faulty oil pressure sensor
- Oil pump failure
- Clogged oil filter
- Engine wear leading to excessive clearances
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with SPN 4191 active?
No, it's not safe to drive as low oil pressure can lead to engine damage.
Will this code come back after repairing?
If the underlying issue is fixed properly (like the sensor or oil pump), the code shouldn't return.
Why does this code pair with other codes?
Related codes often indicate issues with oil pressure or lubrication systems that can affect performance.
Working a real vehicle right now?
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