74
Air conditioning
Air conditioning diagnosis
The diagnosis options listed in the table are
available via the diagnosis tester. For this purpose,
the diagnosis on the CAN-Diagnosis and on the
diagnosis interface for data bus J533 is performed
in Climatronic control unit J255.
All input and output signals of Climatronic control
unit J255 can be diagnosed according to the
following error types:
– Line interruption
– Short circuit after positive
– Short circuit after ground
– Block (control motors)
– Plausibility of data bus signals
The actuator test of the air conditioning system is
now sequentially (complete performance of all
actuator tests) and selectively (selection of
individual actuator tests) possible. The following
conditions must be met before the actuator test can
be performed.
– no compressor switch-off condition active
– Vehicle speed < 5 km/h
– 300 / min < engine speed < 3000 / min
Otherwise the message "Function unknown or
cannot be performed at the moment" is displayed in
the diagnosis tester. During the basic setting of the
air conditioning system, all flap positioning motors
are simultaneously moved to their limit positions.
These positions are then saved in Climatronic
control unit J255. During the basic setting, certain
fault memory entries are deleted, with the exception
of those identified during the basic setting. In
addition, the activation of the compressor is only
allowed after the basic setting. Up until then,
Climatronic control unit J255 remains in ECON
mode, which cannot be deactivated. After the
successful basic setting, Climatronic control
unit J255 remains in ECON mode, which can now,
however, be deactivated at any time by means
of the AUTO or ECON button.
Since Climatronic control unit J255 is component
protected, the exchange of the component without
vehicle-specific adaptions can cause restricted
functionality.
In contrast to the current Audi A8 and Audi A3,
during a recoding of a Climatronic control unit J255,
no information on the networking is taken from the
diagnosis interface for data bus or the engine
control unit. In the case of the Audi A6´05, the
coding is performed completely by the entries at the
diagnosis tester.
323_037
