P252D
Engine Oil Quality Sensor Circuit High
Sensor signal voltage above the upper limit — typically a short to reference voltage or an open signal return.
- 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 reference voltageCommon
- Connector pins corroded - high contact resistanceLess likely
- Supply wire pinched against B+ sourceLess likely
Parts involved
- Oil Quality Sensor
- Sensor Wiring
P252D 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.