Vehicle Coding Information: Introduction
As part of an ongoing process to reduce the need for country, model and option specific control modules, BMW began to utilize a multi digit vehicle coding structure referred to as a Central Coding Key (ZCS) and later changed to a structure referred to as a Vehicle Order (VO/FA).
The Central Coding Key (ZCS) is a unique 37 digit (originally a 48 digit) code that contains specific model, country variation and individual equipment/option information for a vehicle.
During the manufacturing process of a vehicle, the ZCS code is created to identify the specific vehicle being built and to properly code the control modules installed during the assembly process once the vehicle reaches the end of the line. To ensure that the ZCS code can be retrieved once the vehicle leaves the factory it is stored in one or two control modules, depending on the model.
ZCS is often referred to as a "key" since it is able to automatically "unlock" or "activate" specific functions of a new control module or can be used to recode a used control module to be compatible with the specific vehicle it has been installed into. With the introduction of the E31 the ZCS information was used for the first time as a coding key for replacement vehicle control modules, this ensured that the replacement modules would be coded to the required specification of the vehicle.
As the number of options & accessories available for installation in a vehicle increased, an alternative to the ZCS code was introduced on 9/01 production E46 vehicles. The ZCS system was replaced with a system known as the Vehicle Order (VO/FA). The VO is a straight forward listing of vehicle specific information including a list of the option codes pertaining to the systems or equipment installed in the vehicle and is used in the same manner as the ZCS to properly code replacement or additional modules.
Regardless of which structure is utilized on a vehicle, codeable modules have no limit as to the number of times that they can be recoded.