P262A
Fuel Injector - Pilot Injection Not Learned
The pilot (pre) injection learning routine on a common-rail diesel did not complete successfully. Without learned pilot quantity, combustion noise increases and NOx may rise.
- 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 flow drift outside learning windowCommon
- Unstable rail pressure during learning cyclePossible
Parts involved
- Fuel Injector
- High Pressure Pump
- Control Module
P262A 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.