P2B05Cylinder 6 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
- P2B05 marks missed injection pulses on cylinder 6 outside the cold-start window; on a six-cylinder engine this is the last cylinder in the order of numbers. No manufacturer documents P2B05 publicly as a stand-alone check. GM's 2025 V8 calibration (25OBDG06A/06B) lists it only in the support tables shared by the pulse family. One of them shows why the check is tied to split injection: double or triple pulses are allowed only up to about 3,000–3,600 rpm, depending on mode and injector energy profile, and per GM's 2018 definitions single-pulse data are evaluated below 5,000 rpm. A fault therefore tends to show at low and medium speed. The injector of cylinder 6 is first suspect, wiring second; the cold-start counterpart is P2B0D.
- What you may notice
- Check engine light
- Slight shaking at idle or low speed, misfire on cylinder 6 (P0306)
- Likely causes
- LikelyDeposits or wear on the cylinder 6 injector hampering small pulses
- PossibleContact problem at the injector 6 plug
- RareInjector driver or voltage sensing in the ECM faulty
- 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: €100 – €1,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.