P03AE
Cylinder 3 Pressure Too Low
Cylinder 3 measured peak combustion pressure is below the calibrated minimum — typically low compression, weak injection, or stuck-open exhaust valve.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: hard
Common causes
Ordered by how often each turns out to be the cause.
- Low compression on cylinder 3Common
Parts involved
- Cylinder Pressure Sensor
P03AE 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.