Checking pressure signal at refrigerant pressure and temperature sender G395 — AUDI

Checking pressure signal at
refrigerant pressure and temperature sender
G395
Note
The cooling output cannot be checked if the
refrigerant pressure and temperature sender
G395
is removed; the operating and display unit (
Climatronic control unit
J255
) does not switch on the air conditioner compressor
Vehicle diagnostic, testing and information system
VAS 5051/
("Guided Fault Finding")
.
For checking measured values of refrigerant pressure and temperature sender
G395
, refer to
Vehicle diagnostic, testing and information system
VAS 5051/
("Guided Fault Finding")
.
The
refrigerant pressure and temperature sender
G395
uses a local data bus to exchange information with the
onboard supply control unit
J519
. The
J519
transmits the data via the data bus to the operating and display unit (
Climatronic control unit
J255
).
Due to the version of the
refrigerant pressure and temperature sender
G395
and its fitting location, the temperature measured by the
refrigerant pressure and temperature sender
G395
differs from the actual temperature of the refrigerant. Currently this is therefore not evaluated and used for the control of the air conditioner.
This vehicle may only be fitted with a
refrigerant pressure and temperature sender
G395
Electronic parts catalogue
.
After switching off the air conditioner compressor, it might take a relatively long period on this vehicle before the pressure in the high-pressure side drops (the expansion valve is cold and the pressure in the low-pressure side increases rapidly after the compressor is switched off, the expansion valve is closed and the refrigerant can flow to the low-pressure side only slowly).
Preparation
Switch off ignition.
Remove cover (top) for lock carrier
General body repairs, exterior
Rep. gr.
50
Lock carrier; Exploded view - lock carrier
.
Unplug electrical connector
A
.
Assignment of 3-pin connector at
refrigerant pressure and temperature sender
G395
A
Earth
Signal output – to
onboard supply control unit
J519
via local data bus
Terminal
“75”
(positive)
Test sequence:
Switch on ignition.
Check earth and positive connection to connector
A
.
Check connection and operation of
refrigerant pressure and temperature sender
G395
as described in Guided Fault Finding
Vehicle diagnostic, testing and information system
VAS 5051/
("Guided Fault Finding")
.
Note
When the electrical connector
A
is unplugged, the air conditioner compressor (
air conditioner compressor regulating valve
N280
) is not activated.
The
refrigerant pressure and temperature sender
G395
is an electronic control unit which exchanges information via a local data bus with the
onboard supply control unit
J519
Vehicle diagnostic, testing and information system
VAS 5051/
("Guided Fault Finding")
.