light AUDI A4 1997 B5 / 1.G AFC Engine Auxiliary Input Signals Checking Workshop Manual
[x] Cancel search | Manufacturer: AUDI, Model Year: 1997, Model line: A4, Model: AUDI A4 1997 B5 / 1.GPages: 37, PDF Size: 0.15 MB
Page 3 of 37

24-89
       If display value does not change:  
     
-  Switch ignition OFF and connect VAG 1598/19 
test box to ECM harness connector   page 01
-
255
 . 
     
-  Connect VAG 1527B voltage tester between 
VAG 1598/19 test box socket C14 and Ground 
(GND). 
     
-  Switch ignition ON.
     
-  Switch ON rear window defroster.
     
Voltage tester must light up 
      If voltage tester does not light up:  
    
If wiring is OK:  
If rear window defroster is OK:  -  Check wiring for continuity between C14 and rear window defroster 
using wiring diagram. 
-  Check rear window defroster using wiring diagram.
- Replace ECM   page 01
-265
 .
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Page 6 of 37

24-91
      
Checking  
     
-  Start engine and let idle. 
     
-  Switch A/C on, push "AUTO" button, set 
temperature to "LO" and blower speed to "HI". 
     
A/C compressor symbol must light up and 
A/C must run. 
     
-  Using VAG 1551 scan tool, select "Basic 
Setting" function 04, display group 004   page 01
-150
 . 
     
A/C compressor must stop (visual check) 
      If the A/C compressor does not shut off:  
     
-  Switch A/C off (press "minus" button for fresh air 
blower in A/C control head repeatedly, until all 
indicators are off). 
     
   Continue to let engine run in idle.
     
-  Using VAG 1551 scan tool, select "Read 
Measuring Value Block" function 08, display 
group 004. 
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Page 19 of 37

24-98
       If no vehicle speed is displayed between 
standstill and moving:  
     
-  Switch ignition OFF and connect VAG 1598/19 
test box   page 01
-255
 . 
     
-  Connect VAG 1527B voltage tester between test 
box sockets 13C (signal) and 10D (B+). 
     
-  Raise front of vehicle until left-front wheel is free 
to rotate. 
     
Note:  
     The right front wheel must NOT rotate. 
     
-  Switch ignition ON.
     
Voltage tester must light up at half strength 
     
-  Rotate left front wheel by hand.
     Voltage tester must become brighter (flash) 
      If tester does not light up (become brighter) or 
flash:  
     
- 
Check wiring between test box socket 13X and 
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Page 20 of 37

vehicle speed sensor, using wiring diagram. 
    
If wiring is OK, replace vehicle speed sensor.  
If voltage tester does not light up (become brighter) or flash, replace ECM 
 page 01
-265
 .   -  Find and eliminate open circuit in wiring between terminal C13 and 
vehicle speed sensor. 
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Page 23 of 37

24-100
      
- 
Press  button.     
-  Select "End Output" function 06 and press -Q- 
button to confirm input. 
      If a display did NOT change, even though coding 
is OK:  
     
-  Connect VAG 1598/19 test box to ECM harness 
connector  page 01
-255
 . 
     
-  Connect VAG 1527B voltage tester between test 
box sockets 11B (signal) and 10B (constant 
B+/terminal 30). 
     
Voltage tester must light up (with TR selector 
lever in P or N), then go out with drive mode 
(1, 2, 3, R or D) selected 
      If voltage tester lights up and goes out when 
drive mode is selected, even though the range 
indicator in the "Read measuring value block" is 
OK:  
     
- Replace ECM   page 01
-265
 .
      If voltage tester lights up constantly or not at all:  
    
- 
Check wiring for short to ground, short to B+ or open circuit between 
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Page 36 of 37

24-110
      
-  Find and eliminate open or short circuit; repair 
as necessary. 
      If wiring is OK:  
     
-  Replace ABS control module.
      If the ABS control module is OK, but the 
malfunction is still occurring:  
     
- Replace ECM   page 01
-265
 .
     
ABS control module with ABS/EDL/ASR  
     
Notes:  
     
The torque signal is monitored by the 
"Automatic Traction Control" Control Module 
and by the ECM. 
     
       Repair Manual, Brake System On Board 
Diagnostic (OBD), Repair Group 01
   
     
Vehicles with automatic traction control (ASR) 
can be recognized by the ASR indicator light in 
the instrument cluster or by control module 
identification displayed during the ABS On 
Board Diagnostic program sequence. 
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