[amidgeha]

Cylinder 5 Fuel Injector Offset Learning At Min Limit

Zero Fuel Calibration (ZFC) is an algorithm used to detect deviations in individual injector performance from nominal. In an overrun/decel fuel shut-off condition, fuel rail pressure is set to 300 bar and small injections are made from a single injector. The observed acceleration in crankshaft speed is detected and compared to the expected acceleration. If the observed acceleration deviates from the expected acceleration by more than 50%, then an additional routine is called adjusts the injection energizing time until observed acceleration matches expected. This information is then used to adjust all pilot injections on that injector to ensure correct fuel delivery. If the absolute energizing time observed for the test injection to yield the expected acceleration exceeds minimum or maximum limits, a code is set.

The Powertrain Control Module (PCM) sets the OBDII code when the observed energizing time for the test injection is 156 us or more lower than the target 430 us energizing time for the given injector.

Cause:
Faulty Cylinder 5 Fuel Injector
Cylinder 5 Fuel Injector harness is open or shorted
Cylinder 5 Fuel Injector circuit poor electrical connection
Faulty Powertrain Control Module (PCM)

Symptoms:
Check engine light