P05ECCold Start Injection Timing Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- To heat the exhaust after a cold start, a diesel shifts its start of injection, usually later, plus post injections. CARB requires faults of such elements during the cold start strategy to be reported under codes separate from normal operation – hence P05EC. GM's 2025 diesels compare the start of injection requested by the application software with the timing actually scheduled for the injector drivers, during cold start only; a deviation beyond ±4 or ±5 in 88 of 176 or 8 of 16 samples sets the code and the lamp in the first trip. Ford's 2023 diesel instead checks whether the cold start operating mode is really activated when requested (10 s). Mechanical injector timing faults in normal operation are P01CB ff and P020A ff; the petrol counterpart for ignition timing is P050B.
- What you may notice
- Check engine light on
- Usually no driving symptoms
- Possibly more white smoke or rougher running after cold start
- Likely causes
- LikelyEngine module software or internal fault (request and execution differ)
- PossibleCold start mode blocked by other faults (coolant or fuel temperature, rail pressure)
- RareInjector driver or injector circuit
- RareWeak battery during cold start
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €100 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.