Since coding is setting options on a car, it depends on the types of options you wish to change. If you are adding safety or convenience features, most are harmless to the overall function of the part – and in fact, are restoring the part back to the German defaults it was designed with instead of the crippled North-American settings it may be on. For other types of coding, such as engine performance, it could cause strain on other components and cause them to wear more quickly. A dealer under a strict option by option investigation could see that some settings do not match the settings set by the factory, but to do so is time-consuming. If in doubt, performance settings can be reversed back to stock prior to a dealership or other visit.