1995 AUDI A4 change

01-4

Heating and A/C system changes, 1997


On Board Diagnostic changes

New A/C control head -E87- with specific
coding for m.y. 1997, 4-cyl. and 6-cyl. engines.

Notes:
Before performing On Board Diagnostic of A/C
system, ensure A/C control head -E87- is coded
correctly (according to engine application).
A/C control heads beginning with Part No. 8L0
820 043 should only be installed in m.y. 1997
vehicles.
A/C control heads beginning with Part No. 8D0
820 043 must only be installed in vehicles
through m.y. 1996.

CAUTION!
Part numbers are for reference only.
Always check with your Parts Dept. for the
latest information.
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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
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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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01-15

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").
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01-22
Diagnostic Trouble Code (DTC) table

Notes:

DTC changes affecting m.y. 1997 vehicles page 01
-38
.
Diagnostic Trouble Codes (DTC) recognized by A/C control head -E87- and displayed on VAG1551 Scan Tool (ST)
starting on page 01
-24
.
If malfunctions occur only occasionally or if the DTC memory was not erased after repairs, such DTC are displayed as
"sporadic faults." (The contents of DTC memory is retained until erased, "permanent memory").
DTCs and flash codes (only for specific components) appear only in the printout in operating mode -1-, (Rapid data
transfer).
In addition to displayed DTC and affected component descriptions, malfunction cause information is listed in the table
below the DTC code.
After performing repairs and operating the A/C system, DTC memory must always be checked again to confirm the repair.
Before replacing a suspected malfunctioning component, check all appropriate wiring, connections, harness connectors
and Ground (GND) connections.
When checking for the cause of sporadic faults, check all plug connections and wiring between A/C control head -E87-
and any component recognized as being inoperative using wiring diagram.
After replacing AC/heating system components, always perform basic setting (function 04), check DTC memory (function
Pa
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01-25

VAG1551 scan tool display
Possible cause
Corrective action
00600
Temperature Regulator Flap Motor
Position Sensor -G92- for
Temperature Regulator Flap Motor
V681)
Short circuit to ground /SP

Open circuit/short circuit to
positive /SP
Adaptation limit exceeded
Mechanical malfunction. - Short circuit, open circuit in wiring or
incorrect terminal assignment (wires
interchanged) of connectors between -G92-
and -E87-
- Temperature flap not operating freely
- -G92- in -V68- inoperative- Diagnose and repair short circuit,
open circuit in wiring or confirm
terminal assignment using wiring
diagram

- Check for free operation of
temperature flap
- Replace -V68-
00601
Central Flap Motor Position Sensor
G112 in Central Air Flap Motor V70
Short circuit to ground /SP

Open circuit/short circuit to
positive /SP
Adaptation limit exceeded2)
Mechanical malfunction - Short circuit, open circuit in wiring or
incorrect terminal assignment (wires
interchanged) of connectors between -
G112- and -E87-
- Central flap not operating freely
- -G112- in V70 inoperative- Diagnose and repair short circuit,
open circuit in wiring or confirm
terminal assignment using wiring
diagram

- Check for free operation of central
flap3)
- Replace -V70-
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01-26

VAG1551 scan tool display
Possible cause
Corrective action
00602
Footwell/Defrost Flap Motor
Position Sensor G114 in
Footwell/Defroster Flap Motor V85
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 -G114-
and -E87-
- Footwell/defroster flap not operating freely
- -G114- in -V85- inoperative- Diagnose and repair short circuit,
open circuit in wiring or confirm
terminal assignment using wiring
diagram

- Check for free operation of
footwell/defroster flap2)
- Replace -V85-
00603
Footwell/Defroster Flap Motor V85

Blocks or de-energized /SP - Short circuit, open circuit in wiring or
incorrect terminal assignment (wires
interchanged) of connectors between V85
and -E87-
- Footwell/defroster flap flap not operating
freely
- -V85- inoperative- Diagnose and repair short circuit,
open circuit in wiring or confirm
terminal assignment using wiring
diagram

- Check for free operation of
footwell/defroster flap
- Check -V85- using function 03
(Output DTM) page 01
-42

1)This fault only recognized during basic setting.
2) Both end stops must be reached.
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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
ge 35 of 91 A/C s
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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