Audi Q3: Rear Window Defogger
Rear Window Defogger -Z1-, Checking, Vehicles with Manual Climate
Control System (Heater without A/C System)
Procedure
The rear window defogger is switched on via the button
-2- on the A/C Control Module
-J301- (the Heater Control Module -J65-) control head.
Note
- By pressing the button -2-, the
A/C Control Module -J301- (the Heater Control Module -J65-)
control head activates the Vehicle Electrical System Control
Module -J519- via the data bus when the ignition is switched on.
As soon as the Vehicle Electrical System Control Module -J519-
switches on the rear window defroster (only when the engine is
running), the indicator lamp in the button
-2- comes on (the Electrical System Control Module -J519-
sends the return message via the data bus. The rear window
defogger is switched off by pressing button again and by
switching ignition off. Refer to the Owner's Manual and
→ Wiring diagrams, Troubleshooting & Component locations.
- If the measured voltage at terminal "30" at the Vehicle
Electrical System Control Module -J519- falls below a value
stored in the Vehicle Electrical System Control Module -J519- or
the A/C Control Module -J301- (Heater Control Module -J65-)
control head, the rear window defogger is switched off
completely (or the output is reduced), therefore reducing the
load on the Generator -C-. Refer to Vehicle Diagnostic Tester in
the "Guided Fault Finding" function.
- The Rear Window Defogger -Z1- is only activated by the
Vehicle Electrical System Control Module -J519- when the engine
is running. When the engine is off, there is no activation and
no return message from the Vehicle Electrical System Control
Module -J519-. The Light Emitting Diode (LED) in the button
-2- does not come on, or will go
out shortly after the button is pushed. Refer to the Owner's
Manual and
→ Wiring diagrams, Troubleshooting & Component locations.
- If the Rear Window Defogger -Z1- activation must be switched
off due to insufficient voltage, the indicator lamp in the rear
window defogger button -2- in the
A/C Control Module -J301- (the Heater Control Module -J65-)
control head remains switched on. Should it take longer to shut
off, the Vehicle Electrical System Control Module -J519-
switches off the indicator lamp via a message.
- The Guided Fault Finding "Read measured values" function for
the A/C Control Module -J301- (the Heater Control Module -J65-)
control head shows that the rear window defogger is switched on
or why it was not activated even though there was a request.
Refer to Vehicle Diagnostic Tester in the "Guided Fault Finding"
function.
- The function test for the rear window defogger activation is
described. Refer to Vehicle Diagnostic Tester in the "Guided
Fault Finding" function.
- The Rear Window Defogger -Z1- switches itself off when the
outside air temperature is higher than 0 ºC (32 ºF) the
operating time stored in the Vehicle Electrical System Control
Module -J519- (approximately 10 minutes) by the Vehicle
Electrical System Control Module -J519-.
- The Rear Window Defogger -Z1- stays switched on with outside
temperatures less than 0 ºC (32 ºF) until ignition is switched
off (it can be switched on and off manually at any time). If the
temperature becomes greater than 0 ºC (32 ºF) during a driving
period, the Rear Window Defogger -Z1- is switched off after the
operating time stored in the Vehicle Electrical System Control
Module -J519- has elapsed (approximately 10 minutes).
- For vehicles with a Start/Stop System, the rear window
defogger can be switched off for the time in which the stop
function is active (to protect the Battery -A-). However, the
setting for the Rear Window Defogger -Z1- actuation remains
stored. After the engine was started again via the start
function, the rear window defogger is switched on again. Refer
to Vehicle Diagnostic Tester in the "Guided Fault Finding"
function.
Rear Window Defogger -Z1-, Checking, Vehicles with Automatic Climate
Control System
Procedure
The rear window defogger is switched on via the button
-2- on the Climatronic Control
Module -J255- control head.
Note
- By pressing the button -2-, the
Climatronic Control Module -J255- control head activates the
Vehicle Electrical System Control Module -J519- via the data bus
when the ignition is switched on. As soon as the Vehicle
Electrical System Control Module -J519- switches on the rear
window defroster (only when the engine is running), the
indicator lamp in the button -2-
comes on (the Vehicle Electrical System Control Module -J519-
sends the return message via the data bus. The rear window
defogger is switched off by pressing button
-2- again and by switching the
ignition off. Refer to the Owner's Manual and
→ Wiring diagrams, Troubleshooting & Component locations.
- If there is a condition that the rear window defogger cannot
be switched on (short circuit in the connection to the rear
window, interruption in the power supply to the Climatronic
Control Module -J255- control head or to the Vehicle Electrical
System Control Module -J519-), this will be stored as a fault in
the respective control module. Refer to Vehicle Diagnostic
Tester in the "Guided Fault Finding" function.
- If the measured voltage on the Vehicle Electrical System
Control Module -J519- to terminal "30" falls below a value
stored in the Vehicle Electrical System Control Module -J519-,
the rear window defogger will be switched off completely (or the
output will be reduced) to relieve the load on the Generator
-C-. Refer to Vehicle Diagnostic Tester in the "Guided Fault
Finding" function.
- The Vehicle Electrical System Control Module -J519- only
activates the rear window defogger when the engine is running.
If the engine is not running, there is no return message from
the Vehicle Electrical System Control Module -J519- and the LED
in the button -2- for the
Climatronic Control Module -J255- goes out again for a short
time after pressing.
- If the Rear Window Defogger -Z1- activation must be switched
off due to insufficient voltage, the indicator lamp in the rear
window defogger button in the Climatronic Control Module -J255-
remains switched on. If it takes longer than approximately 150
seconds to switch off, the Climatronic Control Module -J255-
will switch off the indicator lamp.
- The Guided Fault Finding "Read measured values" function for
the Climatronic Control Module -J255- control head shows that
the rear window defogger is switched on or why it was not
activated even though there was a request. Refer to Vehicle
Diagnostic Tester in the "Guided Fault Finding" function.
- The function test for the rear window defogger activation is
described. Refer to Vehicle Diagnostic Tester in the "Guided
Fault Finding" function.
- The Rear Window Defogger -Z1- switches itself off when the
outside air temperature is higher than 0 ºC (32 ºF) after the
operating time stored in the Vehicle Electrical System Control
Module -J519- (approximately 10 minutes) by the Vehicle
Electrical System Control Module -J519-.
- The Rear Window Defogger -Z1- stays switched on with outside
temperatures less than 0 ºC (32 ºF) until ignition is switched
off (it can be switched on and off manually at any time). If the
temperature becomes greater than 0 ºC (32 ºF) uring a driving
period, the Rear Window Defogger -Z1- is switched off after the
operating time stored in the Vehicle Electrical System Control
Module -J519- has elapsed (approximately 10 minutes).
- For vehicles with a Start/Stop System, the rear window
defogger can be switched off for the time in which the stop
function is active (to protect the Battery -A-). However, the
setting for the Rear Window Defogger -Z1- actuation remains
stored. After the engine was started again via the start
function, the rear window defogger is switched on again. Refer
to Vehicle Diagnostic Tester in the "Guided Fault Finding"
function.
Coolant Fan
- There are different versions. Refer to the Parts Catalog.
- The Climatronic Control Module -J255- or the A/C Control
Module -J301- control head transmits the request to switch on
the A/C system operation (to cool the condenser) to the engine
control module via the data bus. The engine control module then
activates the fan(s) ( Coolant Fan -V7- and Coolant Fan 2
-V177-) directly or via the Coolant Fan Control Module -J293-.
Refer to
→ Rep. Gr.19; Radiator/Coolant Fan; Radiator, Removing and
Installing and
→ Wiring diagrams, Troubleshooting & Component locations.
- To check the activation of the coolant fans for the
Climatronic Control Module -J255-, refer to Vehicle Diagnostic
Tester in the "Guided Fault Finding" function.
- The respective engine control module continuously switches
the Coolant Fan -V7- and the Coolant Fan 2 -V177- (directly or
via the Coolant Fan Control Module -J293-) to the desired output
(depending on the engine type). Refer to Vehicle Diagnostic
Tester in the "Guided Fault Finding" function and
→ Wiring diagrams, Troubleshooting & Component locations.
Outside Air Temperature Display -G106-
- It is a component of the Instrument Cluster Control Module
-J285-. Refer to
→ Electrical Equipment; Rep. Gr.90; Instrument Cluster; Overview
- Instrument Cluster.
- If the temperature display if faulty, check the measured
value of the Outside Air Temperature Sensor -G17-. Refer to
Vehicle Diagnostic Tester in the "Guided Fault Finding"
function, A/C system, instrument cluster "Read measured values".
Note
If there is a faulty measured value for the Outside Air
Temperature Sensor -G17-, complaints may arise regarding the Air
Conditioning (A/C) system regulation. The Climatronic Control
Module -J255- or the A/C Control Module -J301- control head does
not activate the A/C compressor when the exterior temperature is
too low. Refer to Vehicle Diagnostic Tester in the "Guided Fault
Finding" function.
READ NEXT:
Special tools and workshop equipment
required
Vehicle Diagnostic Tester
Connector Test Set -VAG1594D-
Probe -VAS5051/8-
Test Sequence
- Remove the noise insulation. Refer to
→&n
Handling Refrigerant Safety Precautions
The assemblies and piping system of the air conditioner are
filled with the following refrigerant:
1.1.1.2 Tetrafluorethane (CF3-CH2F
or CH2F-CF3)
Curren
SEE MORE:
Bumper Cover Side Mount, Removing and Installing
Removing
- Remove the rear bumper cover. Refer to
→ Chapter "Bumper Cover, Removing and Installing".
- Remove the bolts -arrows-.
- Remove the bumper cover mount -1-.
Installing
Install in reverse order of removal. Note t
Overview - Brake Pedal
1 - Mounting Bracket
Removing and installing, refer to
→ Chapter "Mounting Bracket, Removing and Installing".
2 - Nut
25 Nm
Always replace if removed
Self-locking
First tighten the nuts -A and B-
3 - Noise Insu