P25AD
Piston Cooling Oil Control Circuit Stuck On
The piston cooling solenoid does not close when commanded off — jets remain active when not needed. Oil pressure to top-end consumers may sag, and warm-up takes longer because the cooling jets remove heat from the pistons during cold start.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: hard
Common causes
Ordered by how often each turns out to be the cause.
- Solenoid stuck openCommon
- Carbon or debris buildup preventing free movementLess likely
- Component wear with age - mechanical playLess likely
Parts involved
- Piston Cooling Solenoid
P25AD 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.