Volkswagen Caddy 2004 Self-Study Programme page 53

Tasks:
The onboard supply control unit activates and controls the following functions:
• Electrical load management
• Outside light control
• Turn signal control
• Wipers, front windscreen
Forwarding of data bus signals to the
wiper motor control unit
• Wipers, rear windscreen
• Heated rear windscreen
The heated rear windscreen is controlled
via the onboard supply control unit when
the button for a heated rear windscreen is
pressed and the alternator generates
enough voltage.
• Interior light control
Terminal 30 via which the interior lights are
supplied with power is controlled by the
control unit for the onboard supply.
• Terminal control, the onboard supply
control unit controls the following
functions:
– Terminal 75x via the relief relay for the
X contact
– Terminal 15 via the relay for voltage
supply terminal 15 in the E-box and on
the relay carrier on the control unit for
the onboard supply.
– Terminal 50 via the relay for voltage
supply terminal 50 in the E-box.
• Dimming, instrument illumination
The dimmable output terminal 58d
supplies the dimmable switches and
instruments with voltage.
• Fuel pump supply
When the driver's door is opened, the
electrical fuel pump is supplied with
voltage by the onboard supply control
unit.
Once the engine has been started, it is
supplied via the engine control unit.
• Alternator exciter
The alternator is excited via the onboard
supply control unit.
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