ECU AUDI A4 1999 B5 / 1.G Heating And Ventilation System Servicing Workshop Manual
[x] Cancel search | Manufacturer: AUDI, Model Year: 1999, Model line: A4, Model: AUDI A4 1999 B5 / 1.GPages: 24, PDF Size: 0.49 MB
Page 1 of 24

87-151
 
  
Heating and ventilation system, 
servicing  Instrument panel air outlets and air guide 
ducts
 
CAUTION! 
Before working on the electrical system: 
Note:  
Air is extracted from the passenger compartment 
through 2 outlets located on both sides of the rear 
luggage compartment area near the bumper   
page 87-157
 . 
Removing and installing   Repair Manual, Body 
Interior, Repair Group 70
    
Obtain security code for anti-theft radio.
 Note customer's pre-set radio stations.
 Disconnect battery Ground (GND) strap.1 - 
Instrument panel top cover 2 - 
Retaining spring for air guide duct 
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Page 9 of 24

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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Page 11 of 24

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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Page 12 of 24

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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Page 15 of 24

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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Page 17 of 24

87-165
      
Heater/air conditioner assembly, 
removing and installing (1997  )
 
     
CAUTION! 
     
Obtain security code for anti-theft radio.
     Note customer's pre-set radio stations.
     Move power seats to most rearward 
position. 
     Switch off ignition and disconnect battery 
ground (GND) strap. 
     
-  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. 
     Dispose of used coolant properly. Check 
local regulations. 
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Page 19 of 24

87-166
 
    
CAUTION! 
A/C refrigerant system must be discharged before removing 
heater/air conditioner assembly.  -  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 boot -C-.
-  Discharge refrigerant system   page 87
-201
 .
    
CAUTION! 
Immediately plug open connections on A/C components and lines to 
prevent dirt and moisture contamination.  - Remove bolt -A-.
-  Remove refrigerant lines from evaporator and secure with tie wraps to 
prevent interference during installation. 
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Page 23 of 24

87-170
 
    
Notes:  -  Foam seal -B- must fit tightly against drain funnel -C-.
-  Plate -A- must be fitted at drain in order to support foam seal.
The drain funnel and foam seal can only be replaced with A/C housing 
with evaporator assembly removed (removing and installing heater/air 
conditioner assembly   page 87
-172
 ). 
The stopper -D- on drain prevents liquid flowing back into the foam 
seal. 
    
Drain funnel -C- must be secured to floor panel and must not impede 
operation of drain valve -E-. 
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