Self Study Program 272 – The Phaeton Onboard Power Supply

VAG SSP 272. This Self-Study Programme covers the design and function of the onboard power supply, that is, the power and data management of the Phaeton.

The onboard power supply of vehicles in the early 1950s consisted of approx. 30 m of cables, some  switches, lights and the ignition system.

The further development of motor vehicles required a constant increase in the number of electrical as well as electronic components.

In today’s luxury performance class vehicles, the length of cable, despite networking, is approx. 3000 m, branching into approx. 1500 individual cables.

Networking connects control units with one another via databus lines. In this way, various signals can be transmitted digitally from one control unit to another. This takes place via two databus lines and  eliminates the need for a separate cable for each individual signal.

It describes new control units that control and regulate the power supply. It also describes, for example, the networking of the lighting control system as well as the CAN bus topology.


  • Introduction
  • Electrics boxes
  • Energy management
  • Onboard supply power management
  • Networked functions
  • Control unit for windscreen heating
  • Switches
  • Dash panel insert
  • Networking
  • Analogue clock
  • Glossary
  • Test your knowledge

The self-study programme involves the design and function of new developments!
The contents are not updated. Please always refer to the relevant Service Literature for all inspection, adjustment and repair instructions.

Language: English
Format: PDF
Pages: 64

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