Components Actuated By A/C System, Electrical Test; General Information; Rear Window Defogger Z1 , Checking - Audi Q7 2007 Repair Manual

Audi Q7 2007 ➤
Heating, Ventilation and Air Conditioning - Edition 04.2013
8 Components Actuated by A/C Sys‐
tem, Electrical Test
⇒ "8.1 General Information", page 80
⇒ "8.2 Rear Window Defogger Z1 , Checking", page 80
⇒ "8.3 Heated Seats and Seat Ventilation, Checking", page 81
⇒ "8.4 Auxiliary Heater Heating Element Z35 , Checking",
page 85
⇒ "8.5 Testing the Fuel-Driven Auxiliary Heater", page 90
8.1

General Information

Note
Various electrical components of the vehicle (for example, the
♦
Heated Rear Window - Z1- and heated seats) which do not
belong to the A/C system are actuated by the Climatronic
Control Module - J255- front A/C control head (or the Rear A/
C Display Control Head - E265- ). Perform an electrical test
using the Vehicle Diagnostic Tester via the "Guided Fault
Finding" function.
From MY 2011, this vehicle has a Start/Stop System for spe‐
♦
cific engines as optional equipment. The stop function can be
inhibited by this, depending on the setting for the climatronic
control module -J255- . If, for example, "defrost" is selected,
the stop function is not possible or will be interrupted and the
engine will start. The same applies in the case of heating and
cooling. The difference between the selected and actual tem‐
perature is greater than a specified value. Use the Vehicle
Diagnostic Tester via the "Guided Fault Finding" function.
8.2 Rear Window Defogger - Z1- , Checking
♦ If there is a condition that prevents the rear window heater from
switching on such as a short circuit in the connection to the
rear window or an open circuit in the voltage supply to the Cli‐
matronic Control Module - J255- front A/C control head, this
will be stored as a fault in the control head. Use the Vehicle
Diagnostic Tester via the "Guided Fault Finding" function.
♦ If the voltage measured at the Energy Management Control
Module - J644- terminal "30" falls below a value stored in the
Energy Management Control Module - J644- , the rear window
defogger is either switched off completely or its output is re‐
duced to relieve the load on the generator (the Climatronic
Control Module - J255- A/C control head reduces the duty cy‐
cle activation from 100% to between 0 and 90%). Use the
Vehicle Diagnostic Tester via the "Guided Fault Finding" func‐
tion.
♦ If heated rear window must be switched off due to insufficient
voltage, indicator lamp in heated rear window button on the
Climatronic Control Module - J255- front A/C control head re‐
mains switched on, however if switch-off is to last longer than
approximately 150 seconds, the Climatronic Control Module -
J255- front A/C control head switches off the indicator lamp.
♦ Measuring value block of the Climatronic Control Module -
J255- front A/C control head indicates that heater of Heated
Rear Window is switched on or why no activation is occurring
despite a request. Use the Vehicle Diagnostic Tester via the
"Guided Fault Finding" function.
80
Rep. Gr.87 - Air Conditioning
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