P268A GMC – Fuel Injector Calibration Not Learned/Programmed

P268A GMC Possible Symptoms

Engine Light ON (or Service Engine Soon Warning Light)

P268A GMC Possible Causes

Fuel injector flow rate programming

P268A GMC Description

The control functions for the fuel injection system are integrated in 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 individual injector.