AUDI A4 1996 B5 / 1.G AFC Engine Coolant Temperature Sensor Checking Workshop Manual
Page 1 of 3
28-25
 
     
Engine Coolant Temperature 
(ECT) sensor, checking 
     
Notes:  
     
To functionally check the Engine Coolant 
Temperature (ECT) sensor   Repair Group 01, 
Read measuring value block, display group 
001, display field 1. 
     
Component locations   page 28
-1 .
     
-  Disconnect ECT sensor harness connector.
    
-  Switch Fluke 83 multimeter to resistance range and measure between 
ECT sensor terminals 1 (signal) and 3 (GND). 
    
Specified values: 
At approx. 20 C (68 F): approx. 2500 At approx. 80 C (176 F): approx. 330 
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Page 2 of 3
If the specified value is not obtained:  
If the specified value is obtained:  -  Replace ECT sensor. 
-  Check wiring between ECT sensor and ECM as follows:
-  Connect VAG 1598/19 test box to ECM harness connector   page 01
-
255
 . 
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Page 3 of 3
28-26
 
    
If the specified values are not obtained:  -  Check wiring for continuity between terminal 3 of ECT sensor harness 
connector and engine Ground (GND). 
  
Specified value: max. 1   -  Check signal wire for continuity between ECT sensor harness 
connector terminal 1 and test box socket 16A. 
  
Specified value: max. 1   -  Check both wires for short circuit to each other.
    
If wiring is OK and the ECT sensor is OK:  -  Eliminate short or open circuit in wiring between ECT sensor and ECM 
connector -A- or engine Ground (GND). 
ECT sensor terminal 
number  ECM Connector A or engine Ground 
(GND)  
1   16A  
3   Engine Ground (GND)  
-  Replace the ECM   page 01
-265
 .
Pa
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perature 
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) sensor, checkin
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11/23/2002 htt
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