1999 AUDI A4 instrument

01-5

Notes:

For m.y. 1997, changes that affect monitoring of
the A/C system by A/C control head -E87- were
made.
Monitored components, locations pages 87
-
101
and Page 87
-113
.

Additional technical data and notes page 01
-
1 .

If a replacement A/C control head is not coded
after installation or if an unrecognized code was
entered, code "04142" (Audi A4 -4cyl. -USA) is
stored.
The A/C control head is no longer connected to
terminal 30 (vehicle electronics). The last input
setting (into the A/C control head) is stored
when the ignition is switched off and retained
when the ignition is switched on.
The duration of time when ignition is off is
calculated by the A/C control head. When
ignition is switched on, the previous "standing
time" is calculated by monitoring a time signal
from the instrument cluster. If more than 4
hours pass since ignition was switched off, the
actual measured values of the outside
Pa
ge 6 of 91 A/C s
ystem, On Board Dia
gnostic
(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

The fresh air blower and control module.
Following components that provide input signals
to the A/C control head -E87- are revised:
Instrument cluster
Pa
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p://127.0.0.1:8080/audi/servlet/Dis
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yp
e=re
pair&id=AUDI.B5.HA01.01.1

01-24

VAG1551 scan tool
display Possible cause
Corrective action
00000
No DTC recognized If "no DTC recognized appears after performing repairs, OBD is ended.
00529 2122
Speed information
missing /SP1) - Open circuit in wiring between Engine Control Module
(ECM), instrument cluster and A/C control head -E87-
- ECM and instrument cluster supply an unusable engine
speed signal - Diagnose and repair open circuit in
wiring using wiring diagram
- Read measuring value block
page 01
-63

- Test engine speed signal
Repair Manual, Fuel Injection &
Ignition, Repair Group 24
00532 2234
Supply voltage

Signal too low /SP - Voltage drops in electrical system to levels of less than
9.5 V2)
- Contact resistance in cable connection to A/C
Refrigerant Low Pressure Switch -F73- - Test Generator (GEN) and Voltage
Regulator (VR)
Repair Manual, Engine
Mechanical, Repair Group 27
- Diagnose and repair contact
resistance using wiring diagram
1)This fault may be generated during Output Diagnostic Test Mode (DTM) (no engine speed signal recognized although A/C
compressor speed detected).
2) If voltage at -E87-connector -C3- drops below 9.5 V, compressor switches off for a minimum of 25 seconds. Compressor
switches on again when voltage exceeds 10.8 V.
Pa
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(OBD
)
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p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
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e=re
pair&id=AUDI.B5.HA01.01.1

01-27

VAG1551 scan tool
display Possible cause
Corrective action
00604
Back Pressure Flap
Motor Position Sensor
G113 in Air Flow Flap
Motor V71

Short circuit to
ground /SP

Open circuit/short
circuit to positive /SP

Adaptation limit
exceeded1)

Inoperative - Short circuit, open circuit in wiring or incorrect terminal
assignment (wires interchanged) of connectors between -
G113- and -E87-
- Air flow flap not operating freely
- -G113- in -V71- inoperative- Diagnose and repair short circuit,
open circuit in wiring or confirm
terminal assignment using wiring
diagram

- Check for free operation of air flow
flap2)
- Replace -V71-
00625
Road speed signal

Implausible signal /SP - Loose terminal in wiring/connections between
Speedometer Vehicle Speed Sensor (VSS) G22, the
instrument cluster or in another component also
connected to this signal (e.g. radio or control module for
cruise control) and -E87-
- Speedometer -G21- or instrument cluster supplying
unusable signal or a component disrupts signal - Diagnose and repair loose terminal
using wiring diagram.





Pa
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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

- Test road speed signal from
Speedometer G21 or from instrument
cluster (check all components
connected to this circuit using wiring
diagram)
1)This DTC only recognized during basic setting.
2)Both end stops must be reached.
Pa
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(OBD
)
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pair&id=AUDI.B5.HA01.01.1

01-28

VAG1551 scan tool display
Possible cause
Corrective action
00779 3133
Outside Air Temperature Sensor G17

Short circuit to ground /SP

Open circuit/short circuit
to positive /SP - Short circuit or open
circuit
between -G17- and -
E87-
- -G17- malfunction- Diagnose and repair short circuit or open circuit in
wiring using wiring diagram
- -G17- electrical test page 01
-115
00785 3211
Instrument Panel Interior Temperature
Sensor G56

Short circuit to ground /SP

Open circuit/short circuit to
positive /SP - Short circuit or open
circuit
between -G56- and -
E87-
- -G56- malfunction- Diagnose and repair short circuit or open circuit using
wiring diagram
- -G56- electrical test page 01
-115
00787 3213
Fresh Air Intake Duct Temperature
Sensor G89

Short circuit to ground /SP
- Short circuit or open
circuit
between -G89- and -
E87-
- -G89- malfunction- Diagnose and repair short circuit or open circuit in
wiring using wiring diagram
- -G89- electrical test page 01
-115
Pa
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ystem, On Board Dia
gnostic
(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

01-30

VAG1551 Scan Tool display
Possible cause
Corrective action
00785 3211
Instrument panel
interior temperature
sensor
-G56
Short circuit or open circuit between
instrument panel interior temperature
sensor -G56- and A/C control head -E87- - Locate short circuit or open
circuit using wiring diagram and
repair
Short circuit to
Ground /SP
Open/Short
circuit to B+ /SP Instrument panel interior temperature
sensor -G56- malfunctioning - Check instrument panel interior
temperature sensor -G56-
electrical testing, page 01
-115

Note for DTC 00785:
For the A/C control head -E87-, the instrument panel interior temperature sensor -G56- is installed with only one display in the
A/C control head -E87-. instrument panel interior temperature sensor-G56- cannot be checked or replaced individually, if
malfunctioning replace A/C control head -E87- completely. VAG1551 Scan Tool display
Possible cause
Corrective action
00796 6) 3234
Interior temperature
sensor fan-V42
Open circuit in power supply to -V42- or in
wiring connection between -V42- and -E87- - Locate and repair open
circuit using wiring diagram
Blocked or no
voltage /SP Interior temperature sensor fan -V42-
malfunctioning - Replace A/C control head -
E87-
6) For an A/C control head -E87- with only one display, the interior temperature sensor fan -V42- is installed in the A/C control
head -E87-; if malfunctioning replace complete unit.
Pa
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ystem, On Board Dia
gnostic
(OBD
)
11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
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pair&id=AUDI.B5.HA01.01.1

01-37

VAG1551 Scan Tool display
Possible cause
Corrective action
01582
Coolant Temperature Signal
Short circuit or open circuit between
instrument cluster and A/C control head -
E87- - Locate short circuit or open circuit
according to wiring diagram and repair
Short circuit to
Ground /SP
Open/Short circuit
to B+ /SP
Incorrect
Signal /SP Instrument cluster malfunctioning- Check signal from instrument cluster.
Note:
The DTC "Coolant Temperature Signal" is only recognized by A/C control heads -E87- with one display.
Pa
ge 50 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