engine AUDI A4 1997 B5 / 1.G APB Engine Evaporative Emission Syst
Page 3 of 6
24-136
      
Checking voltage supply to Evaporative 
Emission (EVAP) Canister Purge Regulator 
Valve (solenoid valve)  
     
Note:  
     The Evaporative Emission (EVAP) Canister 
Purge Regulator Valve receives its power supply 
via the fuel pump relay. 
     
Test requirements 
     
Fuse for EVAP valve OK 
     
-  Disconnect harness connector on Evaporative 
Emission (EVAP) Canister Purge Regulator 
Valve -N80. 
    
The diode test lamp should light up.  
If diode test lamp does not light up:  
 Electrical Wiring Diagrams, Troubleshooting & Component Locations    -  Connect VAG1527 diode test lamp between engine Ground (GND) and 
socket 1 on connector. 
- Operate starter.
-  Check continuity of wiring from socket 1 to fuel pump relay via fuse. 
Repair open circuit if necessary. 
Pa
ge 3 of 6 Eva
porative Emission 
(EVAP
) system, 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.FU04.24.3 
Page 5 of 6
24-137
      
Testing activation of Evaporative Emission 
(EVAP) Canister Purge Regulator Valve  
    
The diode test lamp should blink.  
If the diode test lamp does not blink or lights up continuously:  -  Connect VAG1527 between diode test lamp sockets 1 (B+) and 2 of 
harness connector. 
-  Start output Diagnostic Test Mode (DTM) and select Evaporative 
Emission (EVAP) Canister Purge Regulator Valves -N80   Page 01
-
75
 . (To initiate DTM a second time, the engine must be started and 
switched off) 
    
-  Connect VAG1598/31 test box to multi-pin harness connector for 
engine control module. Do not connect to the engine control module 
itself  Page 24
-20
 . 
Pa
ge 5 of 6 Eva
porative Emission 
(EVAP
) system, 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.FU04.24.3 
Page 6 of 6
24-138
       If the diode test lamp lights up continuously:  
    
If the diode test lamp does not flash:  
 Electrical Wiring Diagrams, Troubleshooting & Component Locations   
If no short circuit or open circuit is found   -  Check for short circuit to Ground (GND) in wiring between contact 2 on 
EVAP valve harness connector and socket 64 on test box. 
-  Check for open circuit as well as short circuit to B+ in wiring between 
contact 2 on EVAP valve harness connector and socket 64 on test box.
   Resistance in wiring: max. 1.5 ohm-  If necessary, repair short circuit to Ground (GND) or open circuit.
-  Replace Motronic Engine Control Module (ECM) -J220   Page 24
-24
 .
Pa
ge 6 of 6 Eva
porative Emission 
(EVAP
) system, 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.FU04.24.3