1997 AUDI A4 AC System On Board Diagnostic Workshop Manual

The fresh air blower and control module.
Following components that provide input signals
to the A/C control head -E87- are revised:
Instrument cluster
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01-7

A/C system changes

Revised heating/air conditioner assembly with
flap motors page 87
-174
.

The air flow flap motor now activates the fresh
air/recirculating air flap as well.
The two way valve for the circulating/fresh air
door, the vacuum unit and the vacuum reservoir
are deleted.

A/C refrigerant circuit changes
New service valve connection on low pressure
side.
Service valve connection for high pressure side
installed in high pressure line in plenum panel
(deleted at condenser).
A/C pressure switch -F129- replaces pressure
switches -F73- and -F118-.
New version "Zexel" compressor and high
pressure line (4-cyl. engines only).
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01-8

VAG1551 Scan Tool (ST), connecting;
A/C control head -E87-, checking
version


Battery Voltage OK
Fuse 22 (S22) OK
Ground (GND) connection on engine and
transmission OK

1996 vehicles

- Open rear passenger ashtray in center console and remove cover for
Data Link Connector (DLC).
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01-9


- With ignition switched off, connect VAG1551 Scan Tool (ST) to Data
Link Connector (DLC) with cable VAG1551/3.
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01-10

1997 vehicles

All vehicles - With ignition switched off, connect VAG1551 (VAG1552) scan tool to
16-pin Data Link Connector (DLC) under dash to left of steering
column, using adapter cable VAG1551/3.
V.A.G - ON BOARD DIAGNOSTIC HELP1 - Rapid data transfer2 - Blink code output

Indicated on display 1) 1) Operating modes 1 and 2 are displayed alternately
- Switch on printer with -PRINT- button (indicator lamp in switch will light
up).
- Switch on ignition or start engine.
- Switch A/C compressor on (press "AUTO" button).
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01-11

- Press button -1- for operating mode "Rapid data
transfer." Rapid data transfer
HELP
Enter address word XX

Indicated on display
Notes:
If display is blank, check wiring to VAG1551/power supply using
Troubleshooting Procedure No. 1 in "Electrical Wiring Diagrams,
Troubleshooting and Component Locations" Manual.
Address word for A/C Heating Electronics: 08
Additional operating instructions can be obtained by pressing the
HELP button on VAG1551 Scan Tool (ST) During testing procedures, the button advances the program to the
next step An incorrect entry can be cancelled with the -C- button
- Press buttons -0- and -8-.
Rapid data transfer
Q
08 - A/C Heating Electronics

Indicated on display
- Press -Q- button to confirm input.
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01-12
If one of the following messages is displayed: Rapid data transfer
HELP
Control module does not answer

Indicated on display
or
Rapid data transfer
HELP
K wire not switchin
g to B+

Indicated on display
- Press HELP button to print out list of possible causes.
Rapid data transfer No si
gnal from control module

- Check wiring to Data Link Connector (DLC) according to wiring
diagram Electrical Wiring Diagrams, Troubleshooting & Component
Locations binder.
Rapid data transfer Error in communication link

If this display appears at the beginning of or during the OBD program,
malfunctions have occurred and data transfer is no longer possible
between the VAG1551 Scan Tool (ST) and the A/C control head -E87-.
Electrical Wiring Diagrams, Troubleshooting & Component Locations
binder - Check wiring to DLC.
Rapid data transfer
Q
08 - A/C Heatin
g Electronics

- After repairing possible causes of the malfunction, press buttons -0-
and -8- to insert "AC/Heating Electronics" address word 08.
- Press -Q- button to confirm input.
Rapid data transfer Scan Tool sends address word 08

Indicated on display
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01-13

8D0820043D A4-Klimavollautomat DXX
Coding 00062 WSC ZZZZZ

Indicated on display after approx. 5 seconds
Readout example shows US/CDN version, Zexel A/C compressor, 6
cylinder gasoline engine
Coding -E87- and code tables page 01
-57
.
8D0 820 043 D: Part Number of A/C control head -E87-A4: A/C Heating Electronics component designationDXX: Software version of A/C control head -E87-Coding: 00062WSC 06812: Dealership code
8L0 820 043B A4-
A/C full
y automatic DXX
Codin
g XXXXX
WSC ZZZZZ

For m.y. 1997 vehicles install only A/C control head -E87- with Part No.
8L0 820 043 up to and including Part No. index letter "C."
8L0 820 043D A4-
A/C full
y automatic DXX
Coding XXXXX
WSC ZZZZZ

For vehicles beginning m.y. 1998 install only A/C control head -E87- with
Part No. 8L0 820 043 from Part No. index letter "D."
CAUTION!
Part numbers are listed here for reference only. Always check with
your Parts department for the latest information.
Pa
ge 16 of 91 A/C s
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