24-51
      
Oxygen sensor heater, checking  
     
Notes:  
     
Z19 = Oxygen Sensor (O2S) heater, bank 1 
     Z28 = Oxygen Sensor (O2S) heater, bank 2
     For functional check of O2S heaters -Z19- or -
Z28-   Repair Group 01, Read measuring 
value block, display group 040 
     
-  Disconnect O2S heater connector -Z19- or -Z28-
(component locations   page 24
-1 ). 
    
If the specified value is not obtained:  -  Switch multimeter (Fluke 83 or equivalent) to measure voltage and 
connect between terminals 1 (B+) and 2 (GND). 
-  Start engine and let idle. 
   Specified value: approx. 12 to 14 volts
-  Check oxygen sensor heater fuse.
-  Check fuel pump relay   page 24
-24
 .
    
-  Check wiring for continuity between terminal 1 and fuse in fuse holder 
using wiring diagram (if necessary check terminal assignments). 
Pa
ge 5 of 7 Heated Ox
yg
en Sensor 
(HO2S
) before Three Wa
y Catal
ytic Converter 
(TWC
), 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.FU01.24.12