1996 AUDI A4 AC System On Board Diagnostic Workshop Manual

01-14

Part
number Comments
8D0 820
043 D - G
Regulation is only switched off in
On Board Diagnostic (OBD)
during output diagnostic test
mode and basic setting.
For vehicles with 6 cylinder
engines, must only be combined
with Zexel compressor.
8D0 820
043 after
H For all vehicles up to m.y. 96.
8L0 820
043 A - C For all vehicles up to m.y. 97 (lighting
via terminal 58 and 58d)
8L0 820
043 after
D For all vehicles up to m.y. 98 without
radio navigation system up to VIN
199999 of m.y. 1999 (lighting
indirectly activated via terminal 58s).
8D0 820
043 K or L Version with only one display (for
vehicles with radio navigation system
up to VIN 199999 of m.y. 1999)
8D0 820
043 after
M Version with only one display (for
vehicles as of VIN 200000 of m.y.
1999)
Pa
ge 17 of 91 A/C s
ystem, On Board Dia
gnostic
(OBD
)
11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.HA01.01.1

01-15

Notes:

Zexel A/C compressors were installed from
start of production. During m.y. 1996,
Nippondenso type compressors are installed as
a running change. These compressors are not
equipped with A/C speed sensor G111.
The A/C control head is coded to reflect the
compressor type installed (Zexel or
Nippondenso).
Vehicles equipped with Nippondenso (Denso)
compressors must have A/C control head with
Part No. index "H" or higher installed to allow
for correct coding.
Follow coding exactly when replacing an A/C
control head -E87-.

Parts catalog microfiche

A/C control head varies after VIN 200000 of
m.y. 1999 for vehicles with and without radio
navigation system (or a radio with a large
control panel), with and without switch for
heated seats (e.g. index "M", "N", "P" or "Q").
Pa
ge 18 of 91 A/C s
ystem, On Board Dia
gnostic
(OBD
)
11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.HA01.01.1

Parts catalog microfiche
Depending on VAG1551 Scan Tool (ST) program card version, 1st and 2nd digit may not
be displayed (readout: e.g. 040 instead of
00040).
Software version of control head is of no
significance for service department.
If a replacement control head is not coded after
installation or if an unrecognized code was
entered, code "00042" (4-cyl. gasoline engine
USA) is stored.
Pa
ge 19 of 91 A/C s
ystem, On Board Dia
gnostic
(OBD
)
11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.HA01.01.1

01-16

Safety precautions

If special testing equipment is required during
road test, note the following:

WARNING!

Special testing equipment must always be
secured on the back seat and must be
operated from there by a 2nd person.
If special testing equipment were to be
operated from the passenger seat, there
could be injuries to the person seated there
in the event of an accident and air bag
deployment.
Pa
ge 20 of 91 A/C s
ystem, On Board Dia
gnostic
(OBD
)
11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.HA01.01.1

01-17

On Board Diagnostic (OBD) functions

A list of On Board Diagnostic functions can be
printed out by pressing the HELP button.
The following functions are available:

List of functions
Page
01 - Check Control Module
Versions Page 01
-8
02 - Check DTC Memory Page 01
-18


03 - Output Diagnostic Test
Mode Page 01
-42


04 - Basic Setting Page 01
-52


05 - Erase DTC Memory Page 01
-55


06 - End Output Page 01
-56


07 - Code Control Module Page 01
-57


08 - Read Measuring Value
Block Page 01
-63


Only the functions listed above can be used for
the "AC/Heating Electronics" OBD program.
Pa
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(OBD
)
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p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.HA01.01.1

-
Press button. Rapid data transfer
HELP
Select function XX

Indicated on display
Pa
ge 22 of 91 A/C s
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(OBD
)
11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.HA01.01.1

01-18

Check DTC Memory (function 02)


- Press buttons -0- and -8- to insert "AC/Heating
Electronics" address word 08 and advance
program until "Select function XX" appears on
display page01
-17
.

- Switch printer on by pressing PRINT button
(indicator lamp in button comes on). Rapid data transfer
HELP
Select function XX

Indicated on display (function selection)
- Press buttons -0- and -2- to select "Check DTC Memory" function 02.
Rapid data transfer
Q
02 - Check DTC Memor
y

Indicated on display
- Press -Q- button to confirm input.
Rapid data transfer
Q
X DTC reco
gnized

Number of stored DTCs is displayed
-
Press button.
Rapid data transfer
Q
No DTC reco
gnized

If "No DTC recognized" is displayed, the program returns to the starting
position after button is pressed page 01
-20
.
Notes:
-
Press button.
If the printer is switched on, stored DTCs are displayed and printed
Pa
ge 23 of 91 A/C s
ystem, On Board Dia
gnostic
(OBD
)
11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.HA01.01.1

out in sequence. If the printer is switched off, the button must be pressed in order to
display the next DTC.
Pa
ge 24 of 91 A/C s
ystem, On Board Dia
gnostic
(OBD
)
11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.HA01.01.1