RAIL GP-FUEL 3443310 - Caterpillar

the manufacturing process, a four digit code is etched on the top surface of the injector's tappet in order to designate the trim code of the injector.The code for each injector is programmed into the engine's ECM during the manufacture of the engine.When an injector is serviced, the new injector's trim code must be programmed into the engine's ECM. The trim code is programmed within the calibration menu that is in the Caterpillar Electronic Technician (ET). If the new code is not entered, the previous injector's characteristics are assumed.Note: Reprogram the new code as soon as possible. This will optimize the engine's performance. This will also prevent any detrimental effects.