P2B19: Cylinder 5 Injection Pulse Offset Exceeded Learning Limit

What it means

The injection pulse offset adaptation for cylinder 5 exceeds the calibrated learning window. Injector aging or fuel pressure drift beyond compensation.

At a glance

• Usually lights the check-engine light
• Affects emissions; the car can fail an emissions test

How it works

The ECM adjusts injection pulse timing or duration by a learned offset for each cylinder to help balance combustion. P2B19 means cylinder 5 needs a correction outside the permitted learning window, which can point to a worn cylinder 5 injector or fuel rail pressure that has drifted beyond what the ECM can compensate for.

Common causes

Most likely first.

1. Injector worn beyond compensation range
2. Fuel rail pressure drift

Symptoms

• Check-engine light
• Rough idle or engine vibration
• Reduced engine performance

How to diagnose it

1. Read freeze-frame data and related codes, noting engine load and fuel rail pressure when the cylinder 5 offset exceeded its learning window.
2. Check live cylinder-balance or injector-correction data to see whether cylinder 5 is the outlier and whether other cylinders show a shared pattern.
3. Inspect the cylinder 5 injector connector and wiring, and check for fuel leaks or signs of recent injector work.
4. Compare commanded and measured fuel rail pressure across relevant operating conditions with the manufacturer's specification to look for pressure drift affecting multiple cylinders.
5. Test cylinder 5 injector operation and delivery using the vehicle's specified procedure, comparing results with the manufacturer's specification.
6. Repair the confirmed injector or pressure-control fault, then clear the code and verify the cylinder 5 correction remains within its learning window.

Common fixes

• Repair a poor connection or damaged wiring at the cylinder 5 injector.
• Correct a confirmed fuel rail pressure control or supply fault.
• Replace the cylinder 5 injector if testing confirms it is worn beyond the permitted correction range.
• Carry out any required cylinder 5 injector coding or adaptation after repair.

Can I keep driving?

Avoid hard acceleration and long trips if the engine is vibrating or down on power; continued operation can worsen drivability and increase emissions. Stop if it runs severely rough or loses significant power, and have the cylinder 5 injector correction and fuel pressure checked promptly.