AUDI A6 1998 C5 / 2.G AHA Engine Multiport Fuel Injection And Ignition System Repair Manual

AUDI A6 1998 C5 / 2.G AHA Engine Multiport Fuel Injection And Ignition System Repair Manual https://www.carmanualsonline.info/img/6/1045/w960_1045-0.png AUDI A6 1998 C5 / 2.G AHA Engine Multiport Fuel Injection And Ignition System Repair Manual

Page 51 of 166

AUDI A6 1998 C5 / 2.G AHA Engine Multiport Fuel Injection And Ignition System Repair Manual 24-39
       If there is no voltage:  
    
If there is still no voltage:  -  Connect multimeter between harness connector terminal 1 (to ECM) 
and vehicle Ground, using VW1594 connector test kit.

Page 52 of 166

AUDI A6 1998 C5 / 2.G AHA Engine Multiport Fuel Injection And Ignition System Repair Manual 24-40
       If there is voltage:  
    
If display = Htg.bC.ON:  
If display switches between "Htg.bC.ON" and "Htg.bC.OFF:"  -  Connect multimeter between harness connector terminal 2 (to ECM) 
and B

Page 53 of 166

AUDI A6 1998 C5 / 2.G AHA Engine Multiport Fuel Injection And Ignition System Repair Manual 24-41
       If there is no voltage:  
     
-  Connect VAG1598/22 test box to ECM harness 
connector  page 01
-67
 . 
    
If wiring is OK:  -  Check wiring for open circuit between ECM/test box and

Page 54 of 166

AUDI A6 1998 C5 / 2.G AHA Engine Multiport Fuel Injection And Ignition System Repair Manual 24-42
      
Oxygen Sensor (O2S) and Oxygen 
Sensor (O2S) control behind TWC, 
checking
 
     
Notes:  
     
Connector for Oxygen Sensor (O2S) behind 
Three Way Catalytic Converter (TWC) -G130- 
(ba

Page 55 of 166

AUDI A6 1998 C5 / 2.G AHA Engine Multiport Fuel Injection And Ignition System Repair Manual Wiring diagram 
     
Test requirements  
     Engine Coolant Temperature (ECT) at least 
80 C (176 F) 
Pa
ge 55 of 166 Motronic Multi
port Fuel In
jection 
(MFI
) and i
gnition s
ystem
11/23/2002 htt

Page 56 of 166

AUDI A6 1998 C5 / 2.G AHA Engine Multiport Fuel Injection And Ignition System Repair Manual 24-43
      
Function test  
     
-  Connect VAG1551 or VAG1552 scan tool and 
press buttons -0- and -1- to insert "Engine 
Electronics" address word 01 (with engine 
running at idle)   page 01
-8 .

Page 57 of 166

AUDI A6 1998 C5 / 2.G AHA Engine Multiport Fuel Injection And Ignition System Repair Manual 24-44
      
-  Compare display and specified values (display 
fields 1-4): 
  
Display fields  
  
1   2   3   4  
Display group 36: Oxygen Sensor (O2S) behind Three Way Catalytic Converter (TWC), Ba

Page 58 of 166

AUDI A6 1998 C5 / 2.G AHA Engine Multiport Fuel Injection And Ignition System Repair Manual 24-45
      
Continuation  
     
-  Road test to condition oxygen sensor (eliminate 
possible contamination) and repeat test. 
      If the values are still NOT OK:  
     
-  Check Oxygen Sensor (O2

Page 59 of 166

AUDI A6 1998 C5 / 2.G AHA Engine Multiport Fuel Injection And Ignition System Repair Manual 24-46
 Evaluation of display group 36  Display group: 
36  
  
  
Display fields: 
1, 3  
Possible malfunction cause  
Corrective action  
approx. 0.435 V  
 
Open circuit in wire -4- between oxygen s

Page 60 of 166

AUDI A6 1998 C5 / 2.G AHA Engine Multiport Fuel Injection And Ignition System Repair Manual 24-47
      
Checking O2S reference voltage  
     
-  Disconnect 4-pin connector for respective 
Oxygen Sensor (O2S) behind Three Way 
Catalytic Converter (TWC). 
    
If voltage is NOT OK:  
If volt