P25AA
Piston Cooling Oil Control Circuit Low
The piston-cooling oil-jet control circuit reads stuck low — short to ground or low-side driver stuck on. The jets may be enabled continuously, raising oil pump load and lowering oil pressure to other consumers.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: hard
Common causes
Ordered by how often each turns out to be the cause.
- Control wire shorted to groundCommon
- Connector pins corroded - high contact resistanceLess likely
- Harness chafing through insulationLess likely
Parts involved
- Piston Cooling Solenoid
P25AA 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.