P2B0ACold Start Cylinder 3 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
- P2B0A stands for missed cold-start pulses on cylinder 3. For the GM 1.2 L LIH with its three cylinders it is the highest cold-start cylinder code, since that engine's 2025 table stops at P2B0A. The same table defines the cold-start window through the summary code P2B95: catalyst below 550 °C, coolant up to 66 °C, 250–3,000 rpm and less than 20 s after start, ending after 500 engine cycles at most – a very short test. Cylinder codes are Type B and decide after 50 to 100 samples. GM bulletin PIP5746 and service update A202310450 (2020–2021 Encore GX, 2021 Trailblazer) both list P2B0A; the cure is ECM reprogramming. Four-cylinder GM engines use the code for their cylinder 3 too. The warm-engine twin is P2B02.
- What you may notice
- Lamp on, code stored only after a cold start
- Engine runs normally once warm
- Likely causes
- LikelyECM software anomaly on the GM 1.2 L LIH (service update A202310450)
- PossibleCylinder 3 injector reacting too slowly when cold
- RareInjector 3 connector with poor contact
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Easy · Usually a job for a workshop.Typical cost: €0 – €800
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.