P25AEPiston Cooling Oil Pressure Too Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- P25AE means the oil pressure reaching the piston cooling jets is below what the engine controller requires, even though the valve circuit itself shows no electrical fault. Volvo and Mack heavy trucks store it as P25AE00. Their bulletins KC-170 (2020, reissued 2021) and CBR 170-8 (May 2025, Mack and Volvo chassis from 2007 onward) cover an inactive P25AE00 set after a hard pull when engine oil pressure briefly drops, with SPN 4811 and SPN 100 named as related. Before parts are swapped, the oil temperature reading is compared with an infrared thermometer; a gap above 5 °F means a new sensor, otherwise technical support takes over. Real causes include low oil level, a tired pump or blocked jets. Lasting low cooling pressure endangers the pistons, so engines may derate.
- What you may notice
- Inactive code after heavy pulling
- Low oil pressure warning at the same time
- Engine derate possible
- Likely causes
- LikelyLow oil level or oil starvation under hard load
- PossibleOil temperature sensor reading wrong (Volvo/Mack bulletin)
- PossibleWorn oil pump or leaking pressure relief valve
- RareClogged oil filter or piston cooling jets
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €50 – €2,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.