P02D2
Cylinder 4 Fuel Injector A Offset Learning At Min Limit
The PCM applies a per-cylinder injector offset (Mengenausgleich) to compensate for production-tolerance differences in injector flow rate. On cylinder 4 the learned correction has reached its minimum value — the injector is delivering significantly more fuel than the calibrated reference and the controller cannot trim it any further.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: hard
Symptoms
- Check engine light on
- Misfire or rough idle on the affected cylinder
- Increased fuel consumption
- Possible fuel smell or smoke from exhaust
Common causes
Ordered by how often each turns out to be the cause.
- Injector over-deliveringCommon
Parts involved
- Fuel Injector
P02D2 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.