1997 AUDI A4 Heating And Ventilation System Servicing Workshop Manual

87-159

Heater/air conditioner assembly
complete with instrument panel,
removing and installing (1996)


- Using VAG1551 function 03, initiate output
Diagnostic Test Mode (DTM) page 01
-42
.

CAUTION!
Before proceeding with removal of instrument panel and heater/air
conditioner complete: - Proceed through output DTM and wait until air flow flap -A- closes via
air flow flap motor V71.
- Cancel output DTM (press VAG1551 button -C-) with closed air flow
flap -A-.
- Discharge refrigerant system page 87
-201
.
- Remove dust and pollen filter page 87
-158
.
Obtain security code for anti-theft radio.Note customer's pre-set radio stations.Move power seats to most rearward position.Disconnect and remove battery.
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87-160

- Release pressure in coolant system by opening
cap at coolant expansion tank.

WARNING!

With hot engine, cooling system is under
pressure.
Coolant expansion tank cap must be
removed slowly.

CAUTION! - Clamp coolant hoses -A- and -B- with VAG3094 (or equivalent) and
remove from heater core inlet/outlet.
- Place catch basin below heater core connection -A- and carefully blow
coolant out of heater core with compressed air through connection -B-.
- Remove A/C system vacuum supply hose from engine and attach at
heater core inlet/outlet.
- Remove boot -C-.
Dispose of used coolant properly. Check local regulations.Do not re-use used coolant.
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87-161


CAUTION!
Immediately plug open connections on A/C components and lines to
prevent dirt and moisture contamination. - Remove bolt -A-: tightening torque 15 Nm (11 ft lb).
- Loosen refrigerant line clamp and remove lines from evaporator.
- Secure refrigerant lines in engine compartment to allow unobstructed
evaporator re-installation.
- Use blank plug from a replacement evaporator -C- to seal the
connections at the evaporator; this also aids with evaporator re-
installation.

- Remove boot -D-.
- Disconnect low pressure switch -F73- electrical connection and secure
connector end to evaporator fixture.
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87-162
Remove glovebox, lower shelf on driver side and
center section of instrument panel complete (trim
and supports)
Repair Manual, Body Interior, Repair Group
70

Detach pedal assembly from instrument panel
mounting (bolt -1-) Repair Manual, Brake
System, Repair Group 46

Remove drivers Airbag unit Repair Manual, Body
Interior, Repair Group 69

Remove steering wheel Repair Manual, Electrical
Equipment, Repair Group 96

Remove steering column -4- from steering gear (bolt
-5-) and secure with wire -3- at hole -2- to prevent
unit from sliding apart Repair Manual,
Suspension, Wheels, Steering, Repair Group 48

Disconnect affected electrical connections to
Electronic box (integrated auxiliary fuse/relay panel)
in left air plenum chamber) Repair Manual,
Electrical Equipment, Repair Group 97

Disconnect all affected electrical connections
between instrument panel assembly and vehicle
Repair Manual, Electrical Equipment, Repair Group
97

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87-163

Remove heater/air conditioner assembly complete
with instrument panel Repair Manual, Body
Interior, Repair Group 70

Note:
The instrument panel must only be placed on a
clean, covered workbench to avoid damaging the
top cover.
- Remove footwell air outlet page 87
-134
.
- Disconnect all electrical connections between
instrument panel and heater/air conditioner
assembly.

Notes: - Remove all screws/bolts between instrument
panel mounting and heater/air conditioner
assembly.
- Separate Instrument cluster from heater/air
conditioner assembly.
- Install in reverse order of removal noting the
following.

Before removing screws/bolts, mark installation
position.
All cable ties removed in order to separate the
instrument panel from the heater/air
conditioner assembly must be re-attached at
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the same point after assembly.
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87-164

Notes:

When re-installing instrument panel and
heater/air conditioner assembly, ensure the A/C
system vacuum supply hose with heater core
fixture, and low pressure switch electrical
connector and evaporator fixture are inserted
together through the plenum chamber
openings.
Ensure evaporator drain is correctly positioned
page 87
-169
.

Connect coolant hoses correctly:
Ensure boot -C- is correctly installed.Hose -A-: return flow to water pump (with vent hole).Hose -B-: supply from cylinder head.

Replace refrigerant line O-rings -A- and -B-.Evaporator refrigerant line fixture bolt tightening torque: 15 Nm (11 ft
lb). Ensure boot -D- and wiring to low pressure switch are correctly
located and secured when installing.
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Install refrigerant lines free of stress.Evacuate refrigerant circuit and charge system with refrigerant R134a
page 87
-204
.
Fill with fresh coolant/anti-freeze and bleed cooling system Repair
Manual, "General, Engine," Repair Group 19.
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