Faulty Engine Control Module (ECM)
Engine Light ON (or Service Engine Soon Warning Light)
Code P268C Buick Description
The control functions for the fuel injection system are integrated into the Engine Control Module (ECM). Each injector’s flow rate information and cylinder position are stored in the memory of both the Glow Plug Control Module (GPCM) and the ECM. The fuel injector flow rate programming must be done when any of the following procedures are performed: The ECM is replaced, the GPCM is replaced, or any fuel injectors are replaced.
If the ECM does not communicate, the flow rate information can be retrieved from the GPCM. If both control modules fail to communicate, the fuel injector flow rate information, or Injection Quantity Adjustment (IQA) flow rate numbers, will need to be retrieved from each injector. The Diagnostic Trouble Code (DTC) will be set when the ECM detects that the end of line injector adjustment code for cylinder 1 to 8 has not been programmed successfully after injector replacement.
P268C Buick Code – Cylinder 1 Injector Data Incompatible