P05EC
Cold Start Injection Timing Performance
During cold-start the ECU adjusts injection timing (post-injection on diesels, intake-stroke timing on direct-injection petrols) to support catalyst light-off. The strategy does not deliver the expected timing - injector response slow or sensor offset.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Injectors slow when coldCommon
Parts involved
- Fuel Injectors
- Cold Start Strategy
P05EC 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.