P160C Cadillac Engine Calibration Information Not Programmed-GPCM

The control functions for the fuel injection system are integrated in the Engine Control Module (ECM). During the manufacturing process, each injector’s flow rate is measured and recorded as injection quantity adjustment (IQA) flow rate data. The flow rate data is then etched as a hexadecimal number on the body of the injector. This data, together with the injector’s cylinder position, is stored in the memory of both the glow plug control module (GPCM) and the ECM. When the ignition is turn ON, both the GPCM and the ECM monitor to ensure that the fuel injection flow rate numbers are present. If any of the injector flow rate numbers are missing, the diagnostic for that control module will set the appropriate DTC.