Checking electrical air conditioner components activated or evaluated via other control units — AUDI

Checking electrical air conditioner components activated or evaluated via other control units
Note
Certain components of the air conditioner are not activated directly by the air conditioner front operating and display unit (
Climatronic control unit
J255
). For example, the
air conditioner compressor regulating valve
N280
is activated via the
onboard supply control unit
J519
. The data are exchanged between the two control units by way of the data bus
Vehicle diagnostic tester
in
“Guided Fault Finding”
mode.
The measured values of certain air conditioner components are no longer evaluated directly by the air conditioner front operating and display unit (
Climatronic control unit
J255
). Thus, for example, the pressure signal of the
refrigerant pressure and temperature sender
G395
is evaluated by the
onboard supply control unit
J519
and the measured values are transmitted by way of the data bus to
J255
Vehicle diagnostic tester
in
“Guided Fault Finding”
mode and
Current flow diagrams, Electrical fault finding and Fitting locations
.
A start/stop system is offered for this vehicle in combination with certain engines. Depending on the setting, the air conditioner front operating and display unit (
Climatronic control unit
J255
), may inhibit the stop function. For example, the stop function is not possible, or the stop function is interrupted and the engine is switched on as soon as the
“defrost”
mode is selected. This also applies if the difference between the set specified temperature and the measured actual temperature exceeds a certain value in heating and cooling mode
Vehicle diagnostic tester
in
“Guided Fault Finding”
mode.
Certain air conditioner functions can be switched on and off via the MMI system (Multi Media Interface) using the
“A/C”
function on the
“Car”
/
“Car systems”
menu. In addition, the operation of the air conditioner can also be influenced by the settings on the MMI (Multi Media Interface) in the
“A/C”
function of the
“Car”
/
“Car systems”
menu. Therefore, if there are problems with these components, first check the settings on the MMI
Infotainment/MMI Operating Manual
.