P252C
Engine Oil Quality Sensor Circuit Low
Sensor signal voltage below the lower limit — typically a short to ground in the signal line or an internal short across the sensor electrode.
- Check engine light: Not always
- Emissions related: No
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Signal wire shorted to groundCommon
- Connector pins corroded - high contact resistanceLess likely
- Harness chafing through insulationLess likely
Parts involved
- Oil Quality Sensor
- Sensor Wiring
P252C is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.