Sensors; Charge Pressure Sender G31; The Altitude Sender F96; Substitute Function And Self-Diagnosis - Audi V6 BITURBO Manual

The following chapter presents the new features of the sensors, provided that they have not
already been described in the chapter on Subsystems of Motronic.

Charge pressure sender G31

The charge pressure sender is located
upstream of the throttle valve control part.
The Motronic supplies the sender with a
voltage of 5 volts and earth.
The signal which the sender generates is a
pressure- proportional voltage ranging from 0
to 5 volts.
At atmospheric pressure (at sea-level), the
voltage is approx. 2.5 volts.
The signal is used for charge pressure control.
The Motronic also needs information on
charge pressure so that it can take counter-
measures if the maximum permissible
pressure is exceeded.

Substitute function and self-diagnosis:

If sender G31 fails, the charge pressure is
controlled via the characteristic curve (engine
speed-dependent). This will result in a
deficiency of engine power.

The altitude sender F96 ....

... is integrated in the engine control unit, as is
normally the case with turbocharged engines.
... is required to control the charge pressure. In
conditions of decreasing air pressure (lower
density), the charge pressure is reduced to
prevent the turbocharger overspeeding.
... influences the air/fuel mixture composition
at engine start-up. The starting mixture is
leaned down with rising altitude.
Charge pressure sender G31
Substitute function and self-diagnosis
If a signal fails, the charge pressure is reduced
to a safe level, which results in a deficiency of
engine power.
Adaption of the injection quantity at start-up
no longer takes place.
The fault message "Control unit defective" is
displayed in the self-diagnosis.

Sensors

SSP 198/29
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