Volkswagen Golf 1999 Service Manual page 3865

A/C refrigerant system
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High pressure sensor -G65-
Where applicable, high pressure
sensor -G65- -B-, transmits a square
wave signal to Coolant Fan Control
(FC) Module -J293- at a rate which
varies according to the refrigerant
system pressure. -J293 reacts to the
pulse rate of the signal from -G65 as
follows:
If the refrigerant system pressure
rises, -J293- switches the
radiator fan(s) to the second
speed.
Where excessive or insufficient
refrigerant system pressure is
present (E.g.: insufficient air flow
over condensor or when
overcharged), -J293- switches
A/C clutch -N25- off (-N25-
controlled by -J293-).
On Climatronic equipped models
it informs the A/C control head -
E87- that the pressure in the
refrigerant system is OK and that
A/C clutch -N25- can be switched
on (-N25- controlled by -J293-).
On applicable engines, the signal
generated by -G65- is also provided
as an input to the Motronic Engine
Control Module (ECM). As the
amount of torque needed to drive the
A/C compressor varies according to
the refrigerant system pressure, the
ECM processes this signal in order
to enhance engine performance.
Notes:
The presence of -G65- is engine
dependant. Where -G65- is not
used, A/C pressure switch -
F129- is used instead
87-84 .
Where -G65- is used, it's wiring
circuit varies according to engine
Página 17 de 21
87-85
Page
13/2/2005