How to replace Common Rail injectors

Are common rail injectors all the same?

No two common rail injectors are exactly the same, even if they are the same type and make. They are extremely precise instruments, so any variations – no matter how small – created during the manufacturing process will affect their performance. At this level of precision, these tiny changes are significant, so each injector needs to be considered unique.

What are the codes found on common rail injectors?

These are codes that are generated when testing the injectors. They relate to the individual characteristics of each one.

What are the codes called?

The codes have many names: Trim code, Compensation code, C2I, IMA, IQA and C4I.

Why do I need to code an injector into the vehicle’s engine management system?

Each common rail injector is unique with its own characteristics and manufacturing variations. When you code an injector into the vehicle’s engine management system, you are telling the vehicle these characteristics so it can compensate for their differences. This is why coding injectors when fitting them is essential.