Specifications

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Electronic Control Module Coding and Programming DME Variant Coding (Bosch Engine Control Modules)
C.3 DME Variant Coding (Bosch Engine Control
Modules)
The variant code is a 4-digit hexadecimal (alphanumeric) code. The variant code is stored in the
control module and activates the specific market-required functions of the control module. Variant
codes can usually be transferred from the old DME to the new DME (providing that old DME has
communication capability). The variant code can also be entered manually.
The factory scan tool downloads the variant code to the DME control module. When the download
is completed, the specific vehicle information for a particular engine group is activated and the
DME is ready for use.
C.4 Central Coding (ZCS)
ZCS is an acronym for the German words, “Zentraler Codierschlussel”, meaning central coding
key. With the introduction of the E31, the ZCS was used for the first time as an encoding key for
replacement vehicle control modules. The ZCS is called a “key” because it automatically “unlocks”
or “activates” the previously installed program of a new control module or codes a used control
module to be compatible with a specific vehicle.
The ZCS is a unique 48-digit code that represents all model and equipment information about a
vehicle. The ZCS code is created by the factory when the vehicle is assigned for a country and
emission application and is used to encode all the installed control modules in the vehicle after
assembly.
The ZCS is stored in one or two modules, which is retrieved by the factory scan tool during the
process of coding a new control module. When installing a replacement ZCS-encodable control
module, the factory tool searches for the location of the ZCS, copies it, and then downloads it to
the new control module. Before the control module coding can work, the coding software checks
the stored ZCS code, coding data, and module version for compatibility. If they do not agree, the
coding program may update and issue a new ZCS.
C.5 Important Tips Regarding ZCS Coding
• If the modules that store the ZCS are replaced, the ZCS code must be manually entered.
Examples of control modules that store the ZCS are the instrument cluster and the EWS.
• There is no limit to the number of times ZCS-encodable control modules can be coded.
• If a control module gets damaged, it automatically reverts to a default setting that may not
function properly.