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Test step 2 ( overheating fuse S24 / overheating sensor G189 and temperature sensor G18 ) > < List of electrical checks

A3 Mk2

Test step 1 (glow plug with flame monitor Q8)
   
Test step 1 (glow plug with flame monitor -Q8-)
Vehicle diagnostic, testing and information system -VAS 5051 A-, measurement mode: Multimeter, resistance measurement (0...100 Ω)
Test stepConnection on heaterComponent(s) checked
l  Test requirements
–  Additional steps
SpecificationMeasures to be taken if reading does not match specification
1.1Connector A, contacts 1 and 2Glow plug with flame monitor -Q8- and corresponding wiring 
–  Greater than 0.15 and less than 1.5 ~Ω.
–  Renew glow plug (with burner element)
1.2Connector A, contact 1 and auxiliary heater housing  
–  ∞ Ω.
–  Renew glow plug (with burner element)

  Note
t  At 25 °C, internal resistance of glow plug is 0.220 Ω +/- 0.033 Ω (rated resistance). It increases linearly with increasing temperature and reaches approx. 0.790 Ω +/- 0.170 Ω at 1000 °C.
t  Resistances of less than 1 Ω cannot be measured as exactly as required using workshop equipment. Therefore this test can only be used to detect a major damage to the component.
t  Resistance characteristic curve of glow plug with flame monitor -Q8- enables auxiliary heater control unit -J364- to detect whether a flame has formed in heater.
t  If a voltage of 10 V is applied to the glow plug with flame monitor, the power input is between 9 and 14 A.
t  If the resistance at connector -A- between contacts 1 and 2 is greater than 1.5 kilo ohms or less than 0.5 milli ohms, a fault is detected by the auxiliary heater control unit -J364- → Guided Fault Finding function of vehicle diagnostic, testing and information system VAS 5051.
t  Checking activation of the glow plug with flame monitor -Q8- → Guided Fault Finding function of vehicle diagnostic, testing and information system VAS 5051.
   
Vehicle diagnostic, testing and information system -VAS 5051 A-, measurement mode: Multimeter, resistance measurement (0...100 Ω)
Test stepConnection on heaterComponent(s) checked
l  Test requirements
–  Additional steps
SpecificationMeasures to be taken if reading does not match specification
1.3Connector housing E, contact 2 and connector housing D, contact 2Earth connection in auxiliary heater control unit -J364- for glow plug with flame monitor -Q8- 
–  Less than 1.5 ~Ω.
–  Renew auxiliary heater control unit -J364- (with combustion air blower -V6-)

   

Test step 2 ( overheating fuse S24 / overheating sensor G189 and temperature sensor G18 ) > < List of electrical checks