24-88
 
     
Auxiliary input signals, 
checking 
     
Rear window defroster signal, checking
 
     
Requirement  
     
Engine Control Module (ECM) coding OK   
page 01
-247
 . 
     
Checking  
     
-  Using VAG 1551 scan tool, select "Read 
Measuring Value Block" function 08, display 
group 004, display field 4   page 01
-249
 . 
Read measuring value block 4 1 2 3 4
    
Indicated on display, note value in display field 4  
CAUTION! 
Do not use the shift inputs (identified by an X) during the RPM 
increase check. 
If display value is OK:     Specified value: 0XX_XX 
-  Switch ON rear window defroster.
   Specified value: 1XX_XX 
Pa
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11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU01.24.25 
         
        
        24-89
       If display value does not change:  
     
-  Switch ignition OFF and connect VAG 1598/19 
test box to ECM harness connector   page 01
-
255
 . 
     
-  Connect VAG 1527B voltage tester between 
VAG 1598/19 test box socket C14 and Ground 
(GND). 
     
-  Switch ignition ON.
     
-  Switch ON rear window defroster.
     
Voltage tester must light up 
      If voltage tester does not light up:  
    
If wiring is OK:  
If rear window defroster is OK:  -  Check wiring for continuity between C14 and rear window defroster 
using wiring diagram. 
-  Check rear window defroster using wiring diagram.
- Replace ECM   page 01
-265
 .
Pa
ge 3 of 37 Auxiliar
y in
put si
gnals, checkin
g
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU01.24.25