OBD-II code · Powertrain (generic, extended)

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.

Is it safe to drive with P25AA?

Usually safe for short trips, but don’t ignore it: the underlying fault can get more expensive over time.

Common causes

  • Most likelyControl wire shorted to ground
  • Less likelyConnector pins corroded - high contact resistance
  • Less likelyHarness chafing through insulation

Repair at a glance

Difficulty
Hard
DIY friendly
Best left to a mechanic
Typical labour
1–4 h
Emissions test
Usually unaffected
Parts involved
Piston Cooling Solenoid

Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.