P2B1CCylinder 7 Injection Pulse Offset Not Learned
- 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
- P2B1C says no learned offset exists for injector 7, which only applies to engines with at least seven cylinders, in practice V8s. No manufacturer publishes a monitor for this code. A GM patent on small-quantity adaption shows that a learn can also fail to finish because results do not settle: several test injections during fuel cut-off are compared, and an injector whose consecutive values scatter too much gets a low confidence rating and is marked suspicious instead of passing. A noisy speed signal, an injector with erratic opening or a leak in the high-pressure system can therefore block a valid value. Bosch's zero-fuel calibration patent rests on the same speed-based detection. CARB (f)(4.2.4)(A)(i) asks for missing learning to be flagged; P2B1D is the out-of-range sibling.
- What you may notice
- Warning lamp
- With an erratic injector, uneven idle or knocking on one cylinder
- Likely causes
- PossibleTest results for injector 7 scattering too much to be accepted
- PossibleLearn restarted after injector or control unit replacement
- RareLeak in the high-pressure system disturbing the test injection
- 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 – €1,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.