24-49
 
     
Heated Oxygen Sensor 
(HO2S) before Three Way 
Catalytic Converter (TWC), 
checking 
     
Heated oxygen sensor, checking  
     
Notes:  
     
G39 = Heated Oxygen Sensor (HO2S), bank 
1 
     G108 = Heated Oxygen Sensor (HO2S) 2, bank 
2 
     Functional check of HO2S -G39- or -G108-   
Repair Group 01, Read measuring value block, 
display group 010 or 041 
     
-  Disconnect Heated Oxygen Sensors (HO2S) -
G39- or -G108- harness connector (component 
locations  page 24
-1 ). 
    
If continuity is not obtained:  - 
Switch multimeter (Fluke 83 or equivalent) to measure resistance ( ) 
and check for continuity between terminal 4 oxygen sensor signal wire 
(measured at oxygen sensor connector) and engine Ground (GND). 
Pa
ge 1 of 7 Heated Ox
yg
en Sensor 
(HO2S
) before Three Wa
y Catal
ytic Converter 
(TWC
), checkin
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11/22/2002 htt
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