Theory Of Operation

The Powertrain Control Module (PCM) performs the task of Energizing Time (ET) correction calculation to determine effective ET at which an expected fuel quantity is actually injected. The correction values for the ET are monitored during fuel cut off. For every rail pressure calibration point, the fuel quantity used for energizing time calibration is corrected by the injector quantity adjustment. For each of these quantities an ET is determined that has been corrected by the filtered energizing time difference. The diagnostic principle is based on commanding zero fuel quantity injections during the decel fuel cut off in order to achieve predefined engine speed change. The diagnostic function continuously monitors corrected ET. This fault code is logged when the PCM determines that inaccurate fuel injection beyond the set limit has occurred. There might be exhaust smoke during cranking. If this DTC was active at the end of the previous key cycle, it will be active during cranking. Progressive cylinder damage may occur if the engine is operated for an extended period of time with this condition.