The MQB Electrical System

The on-board supply wiring harnesses are modular in design which enables consistent assembly and diagnosis for fault location and repair. Along with the standardized electrical components, these modules also include a structured Data-Bus network. Due to the numerous control units connected to this network, the different Data- Bus systems are described in this SSP.

The diagnostic language used by the control modules for internal and external communication is the new Unified Diagnostic Services (UDS) protocol. Previously, the vehicle diagnostic tester had to know three languages to check control module status. UDS decreases the time necessary to check fault memory and allows faster communication between the tester and the vehicle.

The K-line, sometimes used for diagnosis, has been removed for the 2015 Golf. The tester and the Data Bus On Board Diagnostic Interface -J533- have taken over this responsibility using a high-speed CAN -Bus. This connection speeds up vehicle electrical system adaptation processes.

The Data Bus On Board Diagnostic Interface -J533- has additional responsibilities such as controlling component protection.

There are no switches using battery power in the passenger compartment of the MQB. All switches and buttons function using only low control currents. Relays located in different parts of the vehicle perform the switching processes, allowing smaller wires to be used throughout the vehicle, saving weight.