P2B18
Cylinder 5 Injection Pulse Offset Not Learned
The ECM has not yet learned the per-cylinder injection pulse offset for cylinder 5. Combustion equalisation between cylinders cannot be applied until adaptation completes.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Adaptation lost after battery disconnect or ECM resetCommon
- Injector replaced without learn procedurePossible
Parts involved
- Fuel Injector Cyl 5
- ECM
P2B18 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.