What it means
With the piston-cooling jets commanded on, the dedicated oil-pressure sensor in that gallery reads below the safe threshold. Insufficient flow to the jets means real piston cooling is not happening — the ECM warns the driver and may reduce torque to protect the pistons.
At a glance
- Usually lights the check-engine light
How it works
A pressure sensor in the piston-cooling oil gallery reports whether oil is reaching the cooling jets. P25AE sets when the jets are commanded on but gallery pressure falls below the module’s safe threshold, so piston cooling may be inadequate.
Common causes
Most likely first.
- Low engine oil level
- Sludge-clogged oil gallery
- Worn oil pump
Symptoms
- Low oil-pressure warning light or message
- Check-engine light may come on
- Reduced engine power or a protective operating mode
How to diagnose it
- Check the oil-pressure warning and save freeze-frame data, including engine speed, load, oil temperature, and the piston-cooling command.
- Check engine oil level and condition before running the engine further, since low or degraded oil can reduce gallery pressure.
- Compare the piston-cooling pressure reading with other available oil-pressure data to see whether the low reading is limited to that gallery.
- Inspect the gallery pressure sensor connector and wiring for damage or poor contact that could distort the reading.
- Verify pressure with the manufacturer's specified test procedure, then inspect for a restricted gallery or worn oil pump if low pressure is confirmed.
Common fixes
- Top up engine oil to the correct level with the specified oil if it is low.
- Repair a damaged sensor connector or circuit causing an incorrect pressure reading.
- Clear a sludge restriction in the piston-cooling gallery using the manufacturer's procedure.
- Repair or replace a worn oil pump if testing confirms insufficient oil pressure.
Can I keep driving?
Stop the engine if the oil-pressure warning is on or pressure is confirmed low; driving can quickly damage bearings and leave the pistons without cooling. Do not resume heavy-load driving until the cause is corrected.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.