P2B1E: Cylinder 8 Injection Pulse Offset Not Learned
What to do
Drivable, but this is an early warning worth taking while it is cheap. One cylinder is drifting away from its neighbours — commonly a clogging or leaking injector — and the module is running out of trim to hide it. Injector cleaning or one injector now is the good outcome; ignored, unequal cylinders wash bores, dilute oil and load the aftertreatment with what they leave unburnt.
What this code means
The module has no learned injection pulse offset for cylinder 8.
The module has no learned correction for this cylinder's injector — the trim map is empty where it should have a value. Per-injector correction is learned in place and, on many engines, seeded by a calibration code printed on the injector itself and entered when it is fitted. A new injector fitted without its code, injectors swapped between cylinders during other work, or a module replaced or reprogrammed leaves the correction blank — and the module says so rather than injecting on a guess.
The signature is an engine that runs worse right after injector or module work, and the fix is programming, not parts: enter the injector's calibration code, or run the drive-cycle learn the manufacturer specifies. A second injector will run exactly as badly as the first until somebody types the number in.
Likely causes
Start here
Less common
- Injector calibration code entered incorrectly · moderate
- Interrupted module programming · specialist
Symptoms
Components involved
Information, not instruction
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Community experience
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