P2B0CCold Start Cylinder 5 Injection Pulse Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- P2B0C flags cylinder 5 when its injector fails to show an opening signature on the split pulses used to heat the catalyst after a cold start. Publicly it is documented only by GM, in the 2025 V8 table 25OBDG06A, which lists the cold-start codes for all eight cylinders (P2B08–P2B0F): Type B, decision after 50 to 100 samples. For this engine GM's cold-start window is narrow – catalyst below 550 °C, coolant between 6 and 66 °C, 550–2,000 rpm, foot off the pedal (up to 1 %) and less than 100 s after start. No service bulletin naming P2B0C was found. The background is CARB's rule for model years 2026 to 2028 to check missing split pulses in the cold-start phase under separate codes. Warm-engine misses on cylinder 5 would be P2B04.
- What you may notice
- Check engine light after two cold-start trips
- Usually unremarkable running once warm, maybe a short rough idle when cold
- Likely causes
- LikelyCylinder 5 injector not lifting on the short cold-start pulses
- PossibleInjector 5 wiring or connector with a contact fault
- RareECM calibration issue (check for software updates)
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €0 – €1,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.