24-138
      
Voltage supply, checking  
    
If LED tester does not light:  -  Disconnect harness connector for LDP -V144-.
-  Connect VAG 1527B LED voltage tester between connector terminal 3 
(B+) and engine Ground. 
-  Start engine and run engine at idle.
   LED must light up.
-  Check fuse for LDP -V144-.
-  Check wiring for open circuit between terminal 3 and fuse, according to 
wiring diagram. Specified value: max. 0.5  . -  Check fuel pump relay and signal to relay   Page 24
-81
 .
Pa
ge 3 of 12 Eva
porative Emissions 
(EVAP
) system, checkin
g
11/19/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU02.24.4 
24-143
      
Checking EVAP canister purge regulator 
valve voltage supply  
     
Test conditions  
     
Fuse for EVAP canister purge regulator 
valve OK. 
     
-  Disconnect harness connector from EVAP 
canister purge regulator valve. 
    
If LED test light does not light:  
If wiring is OK:  -  Connect VAG 1527B LED voltage tester between connector terminal 1 
and engine Ground. 
-  Operate starter motor. 
   Specified value: LED must light up
-  Check wiring for open circuit between connector terminal 1 and fuse, 
according to wiring diagram. Repair if necessary. 
-  Check fuel pump relay   Page 24
-81
 .
Pa
ge 11 of 12 Eva
porative Emissions 
(EVAP
) system, checkin
g
11/19/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU02.24.4