Interfaces - Audi A6 242 Service Manual

The interfaces
The driving speed signal
(a square wave signal processed by the dash
panel insert, the frequency of which changes
analogously to the speed)
is required in the evaluation of the driving
condition (stationary/driving mode) and
thereby for the selection of the control
criteria (see "Control concept").
Signal T.15 ...
... is used for the evaluation of the system
status, run-on, stationary, driving and sleep
modes.
The door switch signal...
... is an earth signal from the control unit for
central locking. It signals that the door or
boot lid/tailgate is open.
... serves as the "wake-up pulse" for the
transition from sleep mode to run-on mode
(see "Control concept").
Signal T. 50 ...
... signals the control of the starter and is
used to switch off the compressor during the
starting process.
If a low position is detected after a wake-up
pulse, the compressor is actuated
immediately in order to allow the vehicle to
drive off as quickly as possible.
The compressor is switched off during the
starting process to protect the battery and
ensure starting performance.
1 wheel revolution
Driving speed signal (4 pulses)
Signal from speedometer sender (reed contact)
We speak of run-on mode even if the
system is currently in "run-up" mode
(after a wake-up pulse before
commencing driving).
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